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	claims	1. A container for radioactive materials comprising a main hollow body as well as a cover made of at least a first metallic material, said cover being fixed on the main hollow body by means of sealing means made of a second metallic material poured into a groove defined by the cover and the main hollow body of the container, wherein the cover and the main hollow body are made solid with said sealing means by means of a bonding zone, formed by chemical reaction between the first and second metallic materials, wherein the first metallic material comprises a material selected from the group consisting of cast iron and steel, and wherein the second metallic material poured is a material selected from the group consisting of aluminum and aluminum alloys, with the bonding zone being composed of an iron-aluminum alloy. 2. A container for radioactive materials comprising a main hollow body as well as a cover made of at least a first metallic material, said cover being fixed on the main hollow body by means of sealing means made of a second metallic material poured into a groove defined by the cover and the main hollow body of the container, wherein the cover and the main hollow body are made solid with said sealing means by means of a bonding zone, formed by chemical reaction between the first and second metallic materials, and wherein the bonding zone uses an average thickness of between 10 mm and 5 mm. 3. The container as claimed in claim 1 or claim 2, in which the cover comprises an external lateral surface partially defining said groove and comprising two adjacent portions inclined respectively at an angle α and an angle β relative to a direction parallel to a longitudinal principal axis of the container, the angles a and β being acute and opposite so a to produce a corner effect. 4. A process for closing a container for radioactive materials comprising a main hollow body as well as a cover made of at least a first metallic material, said process comprising a stage of placing the cover on said main hollow body of the container so as to form a groove between these two elements, followed by a stage of excess pouring the second metallic material in said groove over a determined period, so as to cause heating of the first metallic material constituting said groove as well as washing the surfaces of this groove, followed by a stage of making sealing means ensuring fixing of the cover onto the main hollow body of the container by pouring a second metallic material into said groove wherein the second metallic material is selected such that it reacts chemically with each first metallic material, so as to form a bonding zone between the sealing means on the one hand, and the cover and the main hollow body of the container on the other hand. 5. The process as claimed in claim 4, in which the stage of placing the cover is followed by a stage of pre-heating the first material constituting the groove. 6. The process as claimed in claim 5, in which the stage of pre-heating is preceded by a preparation stage of the surfaces of the groove. 7. The process as claimed in claim 6, in which the preparation stage of the surfaces of the groove is done by means of at least one preparation technique taken from the group constituted by mechanical, chemical and electrochemical techniques for preparation of surfaces, and techniques for depositing layers of metallic materials. 8. The process as claimed in claim 4, in which the stage of making the sealing means by pouring the second metallic material into said groove is followed by a heating stage of this second material resting in said groove, so as to favor chemical reaction between the first and second metallic materials.
	claims	1. In an apparatus for obtaining an X-ray image of a target located between an X-ray radiation source and a back-stop object, said apparatus including one or more X-ray radiation detectors located rearward of said target and forward of said object, a method for reducing the intensity of X-ray radiation scattered onto a rear surface of a rearmost of said X-ray radiation detectors, said method comprising positioning at least a first X-ray radiation attenuating baffle plate between said rearmost X-ray radiation detector and said object, wherein said first baffle plate is axially aligned with a central longitudinal axis of said detector. 2. In an apparatus for obtaining an X-ray image of a target located between an X-ray radiation source and a back-stop object, said apparatus including one or more X-ray radiation detectors located rearward of said target and forward of said object, a method for reducing the intensity of X-ray radiation scattered onto a rear surface of a rearmost of said X-ray radiation detectors, said method comprising positioning at least a first-type X-ray radiation attenuating baffle plate between said rearmost X-ray radiation detector and said object, wherein said first-type baffle plate is axially aligned with a central longitudinal axis of a detector element of said one or more detectors. 3. An apparatus for reducing the intensity of X-ray radiation scattered onto a rear surface of a rearmost X-ray radiation detector located rearward of an X-ray radiation source and target and forward of a back-stop object, said apparatus comprising at least a first-type X-ray radiation attenuating baffle plate located between said rearmost X-ray radiation detector and said object, wherein said first-type baffle plate is axially aligned with a central longitudinal axis of a detector element of said detector. 4. The method of claim 1 wherein said first baffle plate is further defined as having a surface parallel to a longitudinal axis of said detector. 5. The method of claim 4 wherein said first baffle plate is further defined as having a tubular shape. 6. The method of claim 4 wherein said first baffle plate is further defined as having a surface adjacent to a first longitudinally disposed side of said detector. 7. The method of claim 6 further including positioning a second baffle plate adjacent to a second longitudinally disposed side of said detector. 8. The method of claim 7 wherein said second baffle plate is further defined as having a surface parallel to said second longitudinally disposed side of said detector. 9. The method of claim 8 further including positioning a third baffle plate adjacent to a third longitudinally disposed side of said detector. 10. The method of claim 9 wherein said third baffle plate is further defined as having a surface parallel to said third longitudinally disposed side of said detector. 11. The method of claim 10 further including positioning a fourth baffle plate adjacent to a fourth longitudinally disposed side of said detector. 12. The method of claim 11 wherein said fourth baffle plate is further defined as having a surface parallel to said fourth longitudinally disposed side of said detector. 13. The method of claim 12 wherein said third and fourth baffle plates are further defined as being oriented perpendicularly to said first and second baffle plates. 14. The method of claim 1 wherein said first baffle plate is further defined as being composed at least partially of an X-ray radiation absorbing material. 15. The method of claim 1 wherein said first baffle plate is further defined as being composed at least partially of a metal. 16. The method of claim 1 wherein said first baffle plate is further defined as composed at least partially of a metal having an atomic number Z at least as high as that of iron. 17. The method of claim 2 wherein said first-type baffle plate is further defined as having a tubular shape. 18. The method of claim 2 wherein said first-type baffle plate is further defined as being one of a plurality of first-type baffle plates, each one of which is axially aligned with a central longitudinal axis at a separate detector element of said array. 19. The method of claim 2 wherein said first-type baffle plate is further defined as being one of a plurality of pairs of first-type baffle plates, opposite members of each said pair being located in approximate longitudinal alignment with a first pair of opposite longitudinally disposed sides of a detector element of said array. 20. The method of claim 19 further including the step of positioning a second-type baffle plate between said rear surface of said detector array and said object. 21. The method of claim 20 wherein said second-type of baffle plate is axially aligned with a central longitudinal axis of a detector element of said array. 22. The method of claim 20 wherein said second-type baffle plate is further defined as being one of a plurality of second-type baffle plates, each one of which is axially aligned with a central longitudinal axis of a separate detector element of said array. 23. The method of claim 20 wherein said second-type baffle plate is further defined as being one of a plurality of pairs of second-type baffle plates, opposite members of each said pair being disposed transversely to said first-type baffle plates. 24. The method of claim 23 wherein opposite members of each of said pair of second-type baffle plates are further defined as being located in approximate longitudinal alignment with a second pair of opposite longitudinally disposed sides of a detector element of said array. 25. The method of claim 20 wherein at least one of said first-type and second-type baffle plates is further defined as being composed at least partially of an X-ray radiation absorbing material. 26. The method of claim 20 wherein at least one of said first-type and second-type baffle plates is further defined as being composed at least of a metal. 27. The method of claim 20 wherein at least one of said first-type and second-type baffle plates is further defined as being composed at least partially of a metal having an atomic number Z at least as high as that of iron. 28. The apparatus of claim 3 wherein said X-ray radiation detector is further defined as being an element of an array of detector elements. 29. The apparatus of claim 28 wherein said first-type baffle plate is further defined as being one of a plurality of first-type baffle plates, each one of which is axially aligned with a central longitudinal axis of a separate detector element of said array. 30. The apparatus of claim 29 wherein said first-type baffle plate is further defined as having a tubular shape. 31. The apparatus of claim 28 wherein said first-type baffle plate is further defined as being one of a plurality of pairs of first-type baffle plates, opposite members of each said pair being located in approximate longitudinal alignment with a first pair of opposite longitudinally disposed sides of a detector element of said array. 32. The apparatus of claim 31 further including a second-type X-ray radiation attenuating baffle plate located between said rear side of said X-ray radiation detector and said object. 33. The apparatus of claim 32 wherein said second-type of baffle plate is axially aligned with a central longitudinal axis of a detector element of said array. 34. The apparatus of claim 32 wherein said second-type baffle plate is further defined as being one of a plurality of second-type baffle plates, each one of which is axially aligned with a central longitudinal axis of a separate detector element of said array. 35. The apparatus of claim 32 wherein said second-type baffle plate is further defined as being one of a plurality of pairs of second-type baffle plates, opposite members of each said pair being disposed transversely to said first-type baffle plates. 36. The apparatus of claim 35 wherein opposite members of each of said pair of second-type baffle plates is further defined as being located in approximate longitudinal alignment with a second pair of opposite longitudinally disposed sides of a detector element of said array. 37. The apparatus of claim 32 wherein at least one of said first-type and second-type baffle plates is further defined as being composed at least partially of an X-ray radiation absorbing material. 38. The method of claim 32 wherein at least one of said first-type and second-type baffle plates is further defined as being composed at least partially of a metal. 39. The method of claim 32 wherein at least one of said first-type and second-type baffle plates is further defined as being composed at least partially of a metal having an atomic number Z at least as high as that of iron.
041892542	description	In the drawings 1 designates the bedrock in which the repository is located at a certain depth below the ground level 2. This depth may be for instance 300 to 600 meters. In the bedrock 1 there is excavated an outer cavity the outline of which is designated 53 in FIG. 1, and in this cavity there is left a core 54 of rock. The space between this rock 54 and the outer rock is filled with clay 55 which forms a shell enclosing the core 54 of rock. The core 54 is positioned in relation to the outer bedrock 1 by means of supporting members 56 which may consist of reinforced concrete or of left rock. The core 54 contains an inner cavity 57 of a spherical form. Thus, the core 54 forms a shell of rock around the cavity 57. The cavity 57 communicates through a vertical shaft 58 with a horizontal tunnel 59 which is located adjacent to the ground level. The cavity 57 and the shaft 58 are lined with reinforced concrete 60. The cavity 57 constitutes the storage space for the radioactive material. A vertically standing cylinder 61 of reinforced concrete is placed within the cavity 57. This cylinder is shown in detail in FIG. 3. As seen in this figure the wall thickness of the cylinder may be larger in the central part of the cylinder and decrease towards the ends of the cylinder. At the lower end of cylinder 61 there are arranged two rows of ventilation holes 62 along the periphery of the cylinder. Adjacent to the top end of the cylinder there are also provided a row of holes 63 along the periphery of the cylinder wall. The cylinder 61 rests by its lower end on the bottom part of the cavity 57 while its upper end is at some distance from the top part of the cavity 57. Thus, the cylinder 61 divides the cavity 57 into an outer space between the outside of cylinder 61 and the wall of cavity 57 and an inner space formed by the interior of the cylinder. These spaces communicate with each other through the openings 62 in the lower end of the cylinder 61 and through the open upper end of the cylinder and the holes 63. As shown in FIG. 2 the space in cavity 57 which is not occupied by the cylinder 61 is filled with spherical bodies in the form of balls 64 of concrete which are all of the same diameter. Such a ball 64 is shown more in detail in FIG. 4. The ball is provided with a plurality of through cylindrical openings 65. In the embodiment shown in FIG. 4 there are three such openings. The openings 65 have the form of straight cylinders and seen in a cross-section at right angles to their axes they are so disposed that the center lines are at the corners of an equilateral triangle. Each ball 64 is provided with a hook or strap 66 which is anchored in the ball and by means of which the ball can be lifted and lowered. The balls 64 are so placed in the cavity 57 that the openings extend in a direction at a certain angle to horizontal plane. This angle should be such that the openings terminate in the spaces between the balls. The hook or strap 66 is so located in relation to the openings that when the ball is lowered into the cavity 57 hanging in the hook or strap 66, the openings 65 will automatically assume the desired direction. All the balls 64, both those located outside and those located inside the cylinder 61, are provided with such openings 65. The purpose of these openings is to facilitate the circulation of air within the cavity 57. The radioactive material to be stored in the repository is assumed to be solid and shaped into rods. Thus, spent fuel rods and fuel assemblies from a nuclear reactor can be stored without any further treatment in the repository according to the invention. The rods of radioactive material are entered into the openings 65 in some of the balls 64, namely those balls that are placed within the cylinder 61 and preferably only in those balls 64 which are at the lower part of the interior of cylinder 61. Preferably the cylinder 61 is filled with balls 64 containing radioactive material only to one third of its height. The rods of radioactive material are placed in the openings 65 in the balls 64 in such a way that the rods are spaced from the insides of the openings 65 so that air can freely circulate through the openings along the rods of radioactive material. FIG. 4 shows some fuel assemblies 67 placed in the openings 65 in the ball 64. The rods are positioned within the openings 65 by means of suitable support means (not shown). The cavity 57 is closed by means of a seal 68 located in the shaft 58 near its opening into the cavity 57. The cavity 57 may contain sensing means sensing temperature, pressure and radioactive radiation. These sensing means could be connected with measuring instruments located outside the repository by means of cables 69 which are drawn through the seal 68 and the shaft 58. The construction of the repository can be effected by the use of rock blasting methods well known in the art and will therefore not be described more in particular. The cavity 57 should be lined on its inside with heavily reinforced concrete. The concrete cylinder 61 is manufactured by casting on its place within the cavity 57. The space outside the cylinder 61 is filled with concrete balls 64 which are lowered through the shaft 58. Concrete balls 64 containing radioactive material are placed at the bottom of cylinder 61 and above these balls are placed concrete balls 64 not containing radioactive material. The shaft 58 opens straight above the upper opening of cylinder 61. If so desired the balls 64 can easily be removed from the interior of the cylinder, which may be desirable for instance if the stored radioactive material is to be removed for reprocessing. The tightly stacked concrete balls 64 which fill the cavity 57 contribute to preventing the cavity from collapsing. Therefore, the cavity can be given very large dimensions. The dimensions of the repository will of course be dependent on the amount of radioactive material to be stored in it. A repository for the storage of 350 metric tons of spent fuel from a reactor will for instance have the following dimensions: Radius of cavity 57=20 meters Distance from the center of cavity 57 to the inner side of the clay barrier 55=65 meters The maximum temperature in shell 54 of rock will then amount to about 200.degree. C. and the maximum temperature in the clay shell 55 to less than 50.degree. C. In the embodiment shown in FIG. 1 the clay shell 55 and the space occupied by this shell in the rock has a spherical shape. However, the clay shell 55 and the space occupied thereby could also have other shapes, e.g. cylindrical shape within the scope of the invention.
041585984	abstract	A hot plasma producing device is provided, wherein pellets, singly injected, of frozen fuel are each ignited with a plurality of pulsed laser beams. Ignition takes place within a void area in liquid lithium contained within a pressure vessel. The void in the liquid lithium is created by rotating the pressure vessel such that the free liquid surface of molten lithium therein forms a paraboloid of revolution. The paraboloid functions as a laser mirror with a reflectivity greater than 90%. A hot plasma is produced when each of the frozen deuterium-tritium pellets sequentially arrive at the paraboloid focus, at which time each pellet is illuminated by the plurality of pulsed lasers whose rays pass through circular annuli across the top of the paraboloid. The beams from the lasers are respectively directed by associated mirrors, or by means of a single conical mirror in another embodiment, and by the mirror-like paraboloid formed by the rotating liquid lithium onto the fuel pellet such that the optical flux reaching the pellet can be made to be uniform over 96% of the pellet surface area. The very hot plasma produced by the action of the lasers on the respective singly injected fuel pellets in turn produces a copious quantity of neutrons and X-rays such that the device has utility as a neutron source or as an x-ray source. In addition, the neutrons produced in the device may be utilized to produce tritium in a lithium blanket and is thus a mechanism for producing tritium.
	summary
044407149	description	DETAILED DESCRIPTION OF THE INVENTION Refer to FIG. 1 which schematically discloses the basic concept of a variable pellet implosion site in a fusion reactor. FIG. 1 has the following features which are considered old art in ICF devices: a bottom blanket 1 and top blanket 2 wherein nuclear species are located for the breeding of useful isotopes (tritium and plutonium 239 being usual products); a plurality of radial blanket assemblies 3 wherein useful isotopes may also be generated; a group of fuel assemblies 4 wherein energy may be produced by nuclear fission as induced by neutrons released by the fusion process in the pellet; a pellet injection system 5; a plurality of beam sources 6, the preferred beam being laser light; means for heat removal shown here as a liquid sodium heat exchanger 7 having inlet 8 and outlet 9; a first wall 10, intended to encompass all interior surfaces of the reactor exposed to radiation directly from the pellet fusion burn. The pellet is injected into the reactor by the injection system 5 and by gravity and momentum travels along path A-A in FIG. 1. According to the prior art, the pellet is illuminated by the beams 19 upon reaching the central implosion site 11 which initiates a fusion reaction in the pellet. Radiation (not shown) from the pellet then emanates from site 11 outward striking first wall 10 and all blanket assemblies 1, 2, 3, and fuel assemblies 4. The new feature of this invention is the variation in axial position of the pellet implosion site 11. FIG. 1 shows a range B-B along path A-A which range is a locus of equally spaced points chosen to be implosion sites. The site variation causes the radiation deposited in reactor components to seem to have a line source. The time integrated radiation flux, defined as the fluence, is a line source fluence. Range B-B is limited in length such that no site is prohibitively close to the first wall 10. FIG. 1 shows representative implosion sites 12 and 13. The choice of an implosion site is accomplished by control of the timing of the firing of the laser such that the pellet is located at the desired site, and by control of the path of the laser light. The variation in implosion site along A-A may be accomplished in discrete steps taken between even subsequent pellet shots but may preferentially be achieved by changes made over a period of days or weeks. The description of the implosion site distribution in time and in space along B-B in order to achieve a line source fluence in the radial blanket assemblies 3, fuel assemblies 4, and first wall 10 may be preplanned or developed during reactor operation in response to radiation measurements. Applications may arise in which a non-uniform line source fluence is desired, which can be obtained by an appropriate frequency of implosions along range B-B. The axial variation of the implosion site along B-B matches the fluence to the use of cylindrical geometry in the first wall 10, fuel assemblies 4, and radial blanket assemblies 3. To provide a means of varying the point of implosion for ICF pellets, the optics of the laser system must permit focusing over a locus of points (B-B). Furthermore, the means of achieving this change in focal point should substnatially preserve the characteristics of symmetric illumination to avoid giving the pellet an asymmetric impulse during implosion. A first approach to achieving these conditions is simply to raise or lower the beam sources 6 of the laser beam system as illustrated in FIG. 2. FIG. 2 is a schematic diagram of an ICF reactor in which the beam sources 6 in FIG. 1 have been shown as having a system of optical mirrors 14. As shown in FIG. 2, the final two mirrors 14 in each of the beam sources 6 would be raised and lowered by an amount sufficient to change the locus of implosion sites over the desired distance. The coupling between the beam sources 6 and the remainder of the laser beam system would be accomplished by a sliding joint 15 in a periscope-like arrangement as shown in the detail of FIG. 3 for one of the beam sources 6. This approach would require a flexible penetration 17 for each of the beam sources 6 into the upper and lower access points of the reactor such that some degree of horizontal translation of the beam sources 6 is accommodated as they are raised and lowered. Position C in FIG. 2 is intended to correspond to a laser beam focus at implosion site 13 while position D corresponds to a laser beam focus at implosion site 12. A second arrangement to provide a linear adjustment or a variable locus of implosion sites is illustrated in FIG. 4. FIG. 4 is a schematic of an ICF reactor in which the beam sources 6 are not mobile as are the beam sources 6 in FIG. 2. This concept utilizes the techniques of adaptive optics (see Active Optical Devices and Applications-Volume 228, from the SPIE Proceedings, 1979) to change the curvature as well as the orientation of flexible mirrors 18 in each of the beam sources 6. This change is illustrated for one such flexible mirror 18 in FIG. 5 which shows the flexible mirror 18 in three different configurations with changes in both curvature and angle of inclination. The net effect is variation along range B-B of the focal point of the mirror 18 on line A-A. If done appropriately for all beam sources 6, the focal point of all beams 19 (of which 4 are shown in FIG. 4) will occur at the desired location for pellet implosion along A-A and within B-B. Variations in the focal length of the flexible mirrors 18 on the order of .+-.5% should be sufficient to effect the changes in implosion location of interest to this concept. There is a possibility that the effects of unequal focal lengths in the upper and lower laser beam sources 6 may give an asymmetric illumination and intensity and therefore an upward or downward impulse on the pellet during implosion. If this proves to be a problem, compensation for this asymmetry can be provided by introducing optical aberrations in the adaptive behavior of the optics to ensure symmetric illumination intensity. These aberrations would have the effect of slightly defocusing either the upper or lower beam sources 6 to appropriately adjust the symmetry of the illumination intensity. While in the above, two alternative methods to provide a locus of implosion sites is given, it is obvious that other means including optical, mechanical, and other techniques may be provided to accomplish the controlled aim of laser beams. The invention is not limited to laser fusion but can also be used in systems in which alternative fusion-initiating energy beams, such as electron beams, are employed. The reactors illustrated in FIGS. 1, 2, and 4 will of course have many components which are not included therein since there are not considered part of this invention. It is assumed, for example, that conventional systems will be used to time the firing of the beam sources 6 such that the pellet, in flight, is illuminated by the beam or beams at the proper implosion site. While in the foregoing a general invention has been described, it should be understood that various changes may be made without departing from the true spirit and scope of the invention. For example, the selection of the implosion site might be an automated decision based on a radiation fluence as continuously calculated by a computer using detected radiation flux levels. Therefore, the specification and drawings should be interpreted as illustrative rather than limiting.
053234332	claims	1. A pellet drying apparatus for drying and redirecting a plurality of pellets of a short rod shape being transported for processing, said apparatus comprising: (a) a rotation disc of an approximately circular shape rotatable about a disc axis for redirecting each pellet of said plurality of pellets from an axial direction to a radial direction; (b) a plurality of pellet pockets formed on the outer periphery of said rotation disc for housing each pellet of said plurality of pellets; and (c) a plurality of gas circulation devices having a plurality of gas circulation paths communicating with said plurality of pellet pockets. (a) a pellet drying section comprising a rotation disc of an approximately circular shape rotatable about a disc axis for redirecting each of a plurality of pellets being transported from an axial direction to a radial direction; a plurality of pellet pockets formed on the outer periphery of said rotation disc for housing each pellet of said plurality of pellets in each of said plurality of pellet pockets; and a plurality of gas circulation devices having a plurality of gas circulation paths communicating with said plurality of pellet pockets. (b) a pellet inspection section for recording surface conditions of said two end surfaces and said side surface of each of said plurality of pellets which have been dried in said pellet drying section and have been redirected from an axial direction to a radial direction, and for determining acceptance or rejection of each of said plurality of pellets based on recorded images; (c) grip transporting devices for transporting a plurality of pellets which have been determined to be acceptable in said pellet inspection section; (d) a visual confirmation section for visually inspecting the external appearance of said plurality of pellets transported by said grip transporting devices; and (e) a tray loading device for inserting a tray fully loaded with a plurality of pellets transported from said visual confirmation section by said grip transporting devices into a tray storage rack. (f) an end-surface recording device which transports each of said plurality of pellets periodically, record end surface conditions of said two end surfaces and determines acceptance or rejection of each of said plurality of pellets; and (g) a side-surface recording device comprising a pellet rotation device having a small diameter roller rotating in the same direction and at the same peripheral speed as a proximally-disposed large diameter roller having pellet discharge pockets, for supplying each pellet of said plurality of pellets between said small diameter roller and said large diameter roller periodically, recording the side surface condition of the side surface of each pellet of said plurality of pellets, and determines acceptance or rejection of each pellet of said plurality of pellets based on an linearly translated image of said side surface of each pellet. 2. A pellet drying apparatus as claimed in claim 1, said apparatus further comprising: a pellet displacement monitor which determines changes in the position of the end surface of a pellet being transported in an axial direction; and a pellet transport control device for placing said pellet in a pellet direction change position so as to be housed in a pellet pocket of said rotation disc. 3. A pellet drying apparatus as claimed in claim 2, said apparatus further comprising: a control device for rotating said rotation disc through a specific angle when said pellet displacement monitor determines that said pellet has been placed in said pellet direction change position. 4. A pellet drying apparatus as claimed in claim 2, said apparatus further comprising: a pellet position sensor which determines that a pellet to be housed in said pellet pocket of said rotation disc has been disposed in said pellet direction change position; and a control device for rotating said rotation disc through a specific angle when said pellet displacement monitor determines that said pellet has been placed in said pellet direction change position. 5. A drying apparatus as claimed in claim 1, wherein said plurality of pellet pockets are equidistantly disposed on the circumferential periphery of said rotation disc. 6. A drying apparatus as claimed in claim 5, wherein a plurality of ratchet devices are provided between two neighboring pellet pockets equidistantly around said circumferential periphery with sharp teeth of said ratchet devices facing in the forward rotational direction of said rotation disc. 7. A drying apparatus as claimed in claim 1, wherein said plurality of gas circulation paths comprise a plurality of gas in-ports which direct a gas flow to end surfaces of said plurality of pellets. 8. A drying apparatus as claimed in claim 1, wherein said plurality of gas circulation paths comprise a plurality of gas out-ports so as to enable gas to sweep over the end surfaces of pellets. 9. A drying apparatus as claimed in claim 1, wherein said plurality of gas circulation paths comprise a plurality of gas in-ports which direct a gas flow to end surfaces of pellets; and a plurality of gas out-ports which exhaust gas from opposing end surfaces of said plurality of pellets; wherein said gas in-ports and said gas out-ports are disposed on both end covers of said rotation disc in the radial direction of said rotation disc, and perform intaking and exhausting of gas so as to alternatingly direct said gas flow to both end surfaces of said plurality of pellets. 10. A drying apparatus as claimed in claim 8, wherein each of said in-ports is provided with a gas passage groove having a length longer than a diameter of said end surface of the pellet. 11. A drying apparatus as claimed in claim 1, wherein said plurality of gas circulation paths comprise a plurality of outflow ports which direct air flow against the side surfaces of said plurality of pellets housed in said pellet pockets. 12. A drying apparatus as claimed in claim 11, wherein said outflow ports are aimed at a bottom region of said pellets housed in said pellet pockets. 13. An apparatus for arranging short cylindrical bodies, represented by pellets, each pellet having two end surfaces and a side surface and moving from upstream process to downstream process, comprising: 14. An apparatus as claimed in claim 13, said pellet inspection section comprising: 15. An apparatus as claimed in claim 13, said apparatus further comprising a vacuum suction device disposed between said small diameter roller and said large diameter roller. 16. An apparatus as claimed in claim 13, said apparatus further comprising a pellet collection device, disposed upstream of said pellet drying section, for collecting a plurality of pellets being transported horizontally, and a spacer device for separating a plurality of pellets being transported horizontally in close contact with each other. 17. An apparatus as claimed in claim 16, wherein said pellet collection device becomes activated when an operational problem arises in a downstream section of the pellet drying section.
	claims	1. A method of conducting a controlled fusion reaction, the method comprising:a. inducing a flow of electrons in a discontinuity at a tip of a porous electrode with one of a RF generator device, a microwave generator device or a laser, whereby surface plasmons are excited;b. the tip comprising a lattice structure optionally coated with a getter material for hydrogen or low molecular weight gasses, the lattice structure being imbedded with a source of fusion fuel material;c. the discontinuity defining the boundary of the lattice structure containing said source of fusion fuel material;d. wherein an oscillating flow of electrons primarily along a surface of the electrode is induced in a forward direction toward the tip and in a reverse direction away from the tip, the forward and reverse direction electron flows oscillating at a frequency of at least about 1 GHz; ande. wherein, the oscillating flow of electrons creates an electric field greater than about 108 V/m at said tip, providing localized compression by ponderomotive forces, thereby lowering the Coulomb barrier between two fusing atoms thereby inducing a fusion reaction in said fusion fuel material in a region at or adjacent to the tip. 2. The method of claim 1, the electrode comprising a discontinuity and a fusion fuel material, the fusion fuel material having a particle density within a range of 1012/cm3 to 1023/cm3. 3. The method of claim 1, wherein the fusion fuel material comprises nuclei, the nuclei selected from the group consisting of hydrogen-1, boron-11, lithium-6, lithium-7, deuterium, helium-3, nitrogen-15, carbon-12, and tritium. 4. The method of claim 1, wherein the base structure material is comprised of getter materials for hydrogen or low molecular weight gasses, and other material that can support and carry the fusion fuel. 5. The method of claim 1, wherein the getter material for hydrogen or low molecular weight gasses comprises palladium, copper, or gold. 6. The method of claim 1 wherein the porous electrode contains an interstitial region to absorb fusion fuel material. 7. The method of claim 1, wherein the discontinuity is a sharp tip or annular knife edge, for enhancing an electric field. 8. The method of claim 1, wherein the fusion reaction occurs in the presence of a magnetic field. 9. The method of claim 1, wherein the fusion reaction is aneutronic. 10. A method of conducting a controlled fusion reaction, the method comprising:a. inducing a flow of electrons in a submicron or micron sized fusion device that comprises a discontinuity at the tip of a porous electrode and a fusion fuel material;b. oscillating the induced flow of electrons in a forward direction toward the discontinuity and in a reverse direction away from the discontinuity, the forward and reverse direction electron flows oscillating at a frequency of at least about 1 GHz;c. the discontinuity comprising a lattice optionally coated with a getter material for hydrogen or low molecular weight gasses, the lattice absorbing fusion fuel material;d. wherein, the oscillating flow of electrons creates an electric field greater than about 108 V/m at said discontinuity, providing localized compression by ponderomotive forces,thereby lowering the Coulomb barrier between two fusing atoms thereby inducing a fusion reaction in said fusion fuel material in a region at or adjacent to the discontinuity; ande. associating the submicron or micron controlled fusion device with a sensor adapted to convert fusion product particles into another form of energy. 11. The method of claim 10, wherein the fusion fuel material comprises nuclei, the nuclei selected from the group consisting of hydrogen-1, boron-11, lithium-6, lithium-7, deuterium, helium-3, nitrogen-15, carbon-12, and tritium. 12. The method of claim 10, wherein the porous electrode contains an interstitial region to absorb fusion fuel material. 13. The method of claim 10, wherein the getter material for hydrogen or low molecular weight gasses comprises palladium, copper, or gold.
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	summary
06084938&	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an X-ray projection exposure apparatus used in the manufacture of semiconductor integrated circuits. 2. Description of the Related Art In solid-state devices, such as LSIs (large-scale integrated circuits) and the like, circuit patterns are becoming finer in order to increase the degree of integration and the operation speed thereof. In order to form such fine circuit patterns, reduction projection exposure apparatuses having vacuum-ultraviolet exposure light sources are widely used. The resolution of such a reduction projection exposure apparatus depends on the exposure wavelength .lambda. and the numerical aperture NA of the projection optical system. In conventional exposure apparatuses, an approach of increasing the numerical aperture NA is adopted in order to improve the resolution. However, this approach is now close to the limit of the use because of the resulting reduction in the depth of focus and difficulty in the design and the manufacturing of the dioptric system. Accordingly, an attempt to shorten the exposure wavelength .lambda. is being made. For example, light used for exposure shifts from the g-line (.lambda.=435.8 nm) to the i-line (.lambda.=365 nm) of the mercury lamp, and further to KrF excimer lasers (.lambda.=258 nm). Although the resolution of the apparatus is improved by shortening the exposure wavelength, there is a theoretical limit on the resolution from the wavelength of ultraviolet rays used for exposure. Accordingly, in the extended technique of conventional exposure apparatuses using light, it is difficult to obtain a resolution equal to or less than 0.1 um. Against such a technical background, X-ray reduction projection exposure apparatuses using vacuum-ultraviolet rays or soft X-rays (these two kinds of rays are hereinafter termed "X-rays") as exposure light are attracting notice. SUMMARY OF THE INVENTION It is an object of the present invention to provide a practical X-ray projection exposure apparatus in which the above-described problems are solved. It is another object of the present invention to provide a device manufacturing method having a high productivity using such an exposure apparatus. According to one aspect, the present invention provides an X-ray projection exposure apparatus comprising a mask chuck for holding a reflection X-ray mask having a mask pattern thereon, a wafer chuck for holding a wafer onto which the mask pattern is transferred, an X-ray illuminating system for illuminating the reflection X-ray mask, held by the mask chuck, with X-rays, and an X-ray projection optical system for projecting the mask pattern of the reflection X-ray mask onto the wafer held by the wafer chuck with a predetermined magnification. The mask chuck comprises a mechanism for generating static electricity for attracting and holding the reflection X-ray mask by an electrostatic force. It is preferable that the apparatus further comprises a detection mechanism for detecting an attracting force when attracting and holding the mask on the mask chuck. For example, the detection mechanism comprises a pressure sensor provided on an attracting surface of the mask chuck. It is preferable that the apparatus further comprises means for performing scanning exposure by moving both of the mask chuck and the wafer chuck. For example, the mask chuck holds the mask against gravity. It is preferable that the apparatus further comprises means for changing the electrostatic force for attracting the mask by the mask chuck in accordance with the movement of the mask chuck. It is preferable that the relationship of {(the mass of the mask).times.(acceleration due to gravity+the maximum acceleration of the mask while being moved)/(the maximum coefficient of static friction between the mask and the mask chuck)}.times.(safety factor)<(the attracting force of the mask) is satisfied. It is preferable that a plurality of projections are formed on a mask holding surface of the mask chuck, and the reflection X-ray mask is supported by the plurality of projections. The ratio of the area of contact between the distal ends of the projections and the mask to the entire area of the mask is equal to or less than 10%. It is preferable that the apparatus further comprises means for supplying voids formed between the projections with a cooling gas when the mask is supported on the projections. It is also preferable that the apparatus further comprises a temperature control mechanism for controlling the temperature of the mask chuck. For example, the temperature control mechanism comprises means for supplying the inside of the mask chuck with a temperature controlled medium, and a temperature sensor for detecting the temperature of the mask chuck. It is preferable that the mask chuck comprises a ceramic material or a glass material. It is also preferable that the apparatus further comprises a grounded earth pawl provided at at least a side of the mask chuck for supporting the mask. For example, the reflection X-ray mask has a structure in which the mask pattern, made of an absorbing member, is formed on an X-ray reflecting multilayer film. For example, the X-ray illuminating system comprises a radiation source and a reflecting mirror. For example, the X-ray projection optical system comprises a reduction projection optical system having a plurality of X-ray-reflecting mirrors. According to another aspect, the present invention provides a device manufacturing method comprising the step of transferring a mask pattern onto a wafer using the X-ray projection exposure apparatus having the above-described configuration. According to still another aspect, the present invention relates to a device manufacturing method using an X-ray projection exposure apparatus comprising a mask chuck, a wafer chuck, an X-ray illuminating system, and an X-ray projection optical system. The mask chuck holds a reflection X-ray mask having a mask pattern thereon. The wafer chuck holds the wafer onto which the mask pattern is transferred. The X-ray illuminating system illuminates the reflection X-ray mask, held on the mask chuck, with X-rays. The X-ray projection exposure system projects the mask pattern of the reflection X-ray mask onto the wafer held by the wafer chuck with a predetermined magnification. The mask chuck comprises a mechanism for generating static electricity for attracting and holding the reflection X-ray mask by an electrostatic force. The method comprises the steps of generating static electricity with the mechanism of the mask chuck to hold the reflection X-ray mask with the mask chuck by an electrostatic force, holding the wafer with the wafer chuck, illuminating the reflection X-ray mask with X-rays using the X-ray illuminating system, and projecting the mask pattern of the reflection X-ray mask onto the wafer held by the wafer chuck with a predetermined magnification with the X-ray projection optical system to transfer the mask pattern onto the wafer. The foregoing and other objects, advantages and features of the present invention will become more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
	abstract	A source-collector module for an extreme ultraviolet (EUV) lithography system, the module including a laser-produced plasma (LPP) that generates EUV radiation and a grazing-incidence collector (GIC) mirror arranged relative thereto and having an input end and an output end. The LPP is formed using an LPP target system wherein a pulsed laser beam travels on-axis through the GIC and is incident upon solid, moveable LPP target. The GIC mirror is arranged relative to the LPP to receive the EUV radiation therefrom at its input end and focus the received EUV radiation at an intermediate focus adjacent the output end. An example GIC mirror design is presented that includes a polynomial surface-figure correction to compensate for GIC shell thickness effects, thereby improve far-field imaging performance.
	claims	1. A safety injection tank (SIT) system pressurized by inert gas and steam, for injecting emergency core coolant into a reactor vessel of a nuclear reactor system comprising:a safety injection tank (SIT) into which the inert gas is charged and in which the emergency core coolant is housed, the SIT fluidly connected to the reactor vessel through an emergency coolant injecting pipe;a pressurizer in which the pressurized steam is housed, and on which a safety valve pipe is mounted to discharge the pressurized steam; anda pressure equalization pipe which is selectively openable and closable, and which connects an upper portion of the SIT and an upper portion of the pressurizer to equalize the pressure between the pressurizer and the SIT when the pressure equalization pipe is open, further wherein when the pressure equalization pipe is opened, the SIT shifts from a first pressure operation mode charged with the inert gas to a second pressure operation mode, wherein the second pressure operation mode has increased pressure over the first pressure operation mode provided by the pressurized steam during an accident that pressurizes the reactor system, so that the emergency core coolant is introduced into the reactor vessel. 2. The SIT system according to claim 1, further comprising an inert gas exhaust pipe which connects the upper portion of the SIT to the safety valve pipe, wherein the safety valve pipe includes a safety valve configured discharge the inert gas when the pressurized steam of the pressurizer is introduced into the safety injection tank. 3. The SIT system according to claim 1, wherein the inert gas is nitrogen gas and the first pressure is approximately 4.3 MPa, and the second pressure is approximately 17 MPa. 4. The SIT system according to claim 2, further comprising:an injection isolation valve mounted on the emergency coolant injection pipe;a pressure equalization valve mounted on the pressure equalization pipe; andan inert gas exhaust isolation valve mounted on the inert gas exhaust pipe, wherein the injection isolation valve, the pressure equalization valve, and the inert gas exhaust isolation valve are motor operated valves configured to be opened and closed by a separate battery power during station blackout event even when there is a loss of off-site and on-site power generation. 5. The SIT system according to claim 2, wherein the inert gas is nitrogen gas and the first pressure is approximately 4.3 MPa, and the second pressure is approximately 17 MPa. 6. The SIT system according to claim 4, wherein the inert gas is nitrogen gas and the first pressure is approximately 4.3 MPa, and the second pressure is approximately 17 MPa. 7. A safety injection tank (SIT) system pressurized by inert gas and steam, for injecting emergency core coolant into a reactor vessel of a nuclear reactor system comprising:a safety injection tank (SIT) into which the inert gas is charged and in which the emergency core coolant is housed, the SIT fluidly connected to the reactor vessel through an emergency coolant injection pipe, the SIT configured to shift between a plurality of emergency core coolant injection modes, the emergency core coolant injection modes including at least a first pressure operation mode and a second pressure operation mode,a pressurizer for storing the pressurized steam,a pressure equalization pipe comprising a pressure equalization valve that connects the SIT to the pressurizer, wherein the pressure equalization valve is selectively openable to equalize the pressure between the pressurizer and the SIT, further wherein opening of the pressure equalization valve causes the SIT to shift from the first pressure operation mode to the second pressure operation mode,wherein in the first pressure operation mode the inert gas charged SIT is configured to inject the emergency core coolant into the reactor system under a first pressure condition of the reactor system, and wherein in the second pressure operation mode, the pressure equalization valve is opened to provide increased pressure by the pressurized steam to the SIT to inject the emergency core coolant into the reactor system under a second pressure condition of the reactor system; andone or more valves, comprising at least the pressure equalization valve, wherein the one or more valves are driven by a backup emergency power source during a station blackout accident with a loss of off-site and on-site power including emergency generators of a nuclear power plant due to malfunction, to thereby enable injection of the emergency core coolant into the reactor system. 8. The SIT system according to claim 7, further comprising:an emergency coolant injecting pipe connecting the SIT to the reactor vessel;wherein the pressurizer comprises a safety valve pipe to discharge the pressurized steam; andwherein the SIT is configured to shift from the first pressure operation mode to the second pressure operation mode such that the emergency core coolant in the SIT is capable of being introduced into the reactor vessel even when the pressure in the reactor system exceeds the pressure of the SIT in the low pressure operation mode. 9. The SIT system according to claim 7, wherein the inert gas is nitrogen gas and the first pressure is approximately 4.3 MPa, and the second pressure is approximately 17 MPa. 10. The SIT system according to claim 8, further comprising an inert gas exhaust pipe which connects an upper portion of the SIT to the safety valve, wherein the safety valve is configured to selectively discharge inert gas when the pressurized steam of the pressurizer is introduced into the SIT. 11. The SIT system according to claim 8, wherein the inert gas is nitrogen gas and the first pressure is approximately 4.3 MPa, and the second pressure is approximately 17 MPa. 12. The SIT system according to claim 10 wherein the one or more valves comprise:an injection isolation valve mounted on the emergency coolant injection pipe;the pressure equalization valve mounted on the pressure equalization pipe; andan inert gas exhaust isolation valve mounted on the inert gas exhaust pipe, wherein the injection isolation valve, the pressure equalization valve, and the inert gas exhaust isolation valve are motor operated valves configured to be opened and closed during a station blackout event even when there is a loss of off-site and on-site power generation. 13. The SIT system according to claim 10, wherein the inert gas is nitrogen gas and the first pressure is approximately 4.3 MPa, and the second pressure is approximately 17 MPa. 14. The SIT system according to claim 12, wherein the inert gas is nitrogen gas and the first pressure is approximately 4.3 MPa, and the second pressure is approximately 17 MPa.
039742695	description	THE INVENTION In accordance with the process of this invention, the presence of N.g. antibodies in serum is detected by a process which comprises the steps of: A. adding anti-human IgG to the serum to be tested in a buffered aqueous medium, PA1 B. thereafter adding a heat labile antigen which has been produced by a growth culture of N.g. and labeled with a radioactive element, PA1 C. incubating the resulting mixture at from about 4.degree. to 45.degree.C for from about 24 to 2 hours at a pH of from about 6.5 to 8.5 to form an antigen-antibody conjugate when said antibodies are present, and PA1 D. determining the level of radioactivity as a measure of the presence of the antigen-antibody conjugate. The antigen which is used in this test is the heat labile antigen described in the above identified copending patent application. For the purpose of the test method which is described and claimed herein, the antigen is labelled with a radioactive element, the presence of which can be detected by ordinary means such as a counter. The method of growth and isolation is as described below. The process is applicable to a number of N.g. organisms including those identified above by their ATCC numbers and to known organisms identified in our culture collection by the code designation B-273, B-125 and B-2169. Cultures of N. gonorrhoeae B-370 are maintained in a lyophilized state or on semisolid medium and reconstituted as needed. Tissue culture bottles (29 oz.) containing 80 to 100 ml of a charcoal medium are inoculated with a sterile physiological saline suspension of cells, which had been grown for 18 hr. on rabbit chocolate agar slants at 35.degree. in a 4 to 8% CO.sub.2 atmosphere. After 18-24 hr., the cells are again suspended in saline and transferred to metal trays each containing about one liter of the charcoal medium. Following an overnight incubation, the cells are harvested by washing each tray with 150-200 ml of sterile physiological saline. The resulting suspension is filtered through sterile gauze and the filtrate centrifuged at 10,000 rpm in a Sorvall RC2-B centrifuge at 5.degree. for 10 min. The cell pellets are pooled, weighted and suspended in a solution of isotonic saline containing 0.3% sodium dodecyl sulfate (SDS), (4.0 ml/gm of cells wet wt.). This suspension is homogenized gently for 10 min. at room temperature, then centrifuged at 15,000 rpm for 10 min. The supernatant fraction is pooled and the cell pellets were reextracted with 0.1% SDS as before. The combined SDS supernatant fractions were centrifuged at 5,000 rpm to remove residual cells and were stored at 4.degree. in 0.02% sodium azide. The antigenicity of these extracts, in addition to those purified by the following procedure, are monitored by a fluorescent inhibition assay described in the above identified copending application. The combined SDS extracts concentrated at 4.degree. to 15 mg/ml in an Amicon ultrafilter with a PM-10 membrane at 10 psi. Twenty ml of concentrate are applied to a 5.0 .times. 95-cm column of Bio-Gel A-5 m (100-200 mesh) which had been equilibrated previously in 0.05 M NH.sub.4 HCO.sub.3 containing 0.01% sodium azide. Elution of the column is continued at 4.degree. with this solution at a flow rate of 64 ml/hr. Fractions of 20 ml are collected and those containing the GC-antigen are combined (Fractions 35-45) and concentrated to 1 mg/ml of protein in an Amicon ultrafilter as described above. The agarose column purified GC-antigen (6.6 mg of protein in 6.0 ml of 0.05 M NH.sub.4 HCO.sub.3) is mixed with 0.5 mg of crystalline deoxyribonuclease and 0.25 mg crystalline ribonuclease and the resulting solution dialyzed for 24 hr. at 25.degree. against two 2-liter changes of 0.05 M NH.sub.4 HCO.sub.3, 0.01 M MgCl.sub.2, and 0.01% sodium azide. Most of the protein is recovered as revealed by Lowry protein analysis but much of the nucleic acid is removed as indicated by a decrease in absorbance at 280 nm of 48% and of 67% at 260 nm. The nuclease-treated GC-antigen mixture is then chromatographed at 4.degree. on a 2.0 .times. 42-cm column of Bio-Gel A-1.5 m (100-200 mesh) previously equilibrated with 0.05 M NH.sub.4 HCO.sub.3. Fractions of 3.2 ml are collected at a flow rate of 9.6 ml/hr. The GC-antigen elutes as a single sharp peak at the void volume of the column (fractions 14-18) and is concentrated in an Amicon ultrafilter at 10 psi with a PM-10 membrane. The protein recovery is 60%. The above partially purified GC-antigen is iodinated by a slight modification of the procedure of Syvanen et al. as described in J. Biol. Chem. 248, 3762 (1973) in which the following components are incubated at room temperature for 30 sec: 10 .mu.l of 1 mM KI; 10 .mu.l of Na.sup.125 I (7.7 .times. 10 7 cpm); 10 .mu.l of 1.5 mM chloramine T; and 2 .mu.l of 1 N H.sub.2 SO.sub.4. To this solution is added 25 .mu.l of 0.5 N potassium phosphate, pH 7.1, and 0.1 ml of partially purified GC-antigen (44 .mu.g of protein) containing 0.05% SDS. After an additional 2-4 min of incubation, 10 .mu.l of 1 M2-mercaptoethanol is added and the resulting solution passed through a 0.9 .times. 26-cm column of Bio-Gel A 1.5 m (100-200 mesh). The column, equilibrated previously with 0.05 M potassium phosphate, pH 7.0, is developed with this buffer at a flow rate of 20 ml/hr. Fractions of 1.2 ml are collected. The iodinated GC-antigen elutes sharply between tubes 6-8 while .sup.125 iodide ion elutes between tubes 13-18. To each 0.5 ml of the pooled GC-antigen was added 1.4 ml of 1% bovine serum albumin (BSA) containing 0.02 M EDTA and 0.1 ml of 1% sodium azide. The antigen-antibody conjugate is formed by a reaction which takes place in an aqueous medium at a pH of from about 6.5 to 8.5 during a period of from about 24 to 2 hours at a temperature of from about 4.degree.C to 45.degree.C. Reaction is effected by mixing the serum under test with an aqueous buffer and adding anti-human IgG followed by the addition of the labelled antigen. The order of addition is most important and most unexpected. The normal procedure for the preparation of conjugates is to add the antigen to the serum and then to add the antihuman IgG. Unexpectedly, it has been discovered that with the heat labile antigen of this invention, the normal procedure is inapplicable, because the test is not sufficiently sensitive to distinguish between positive and negative sera with a useful degree of confidence. However, following the abnormal order of addition of this invention, the test is remarkably sensitive, reproducible and capable of detecting positive males and females at a percent of as high as 85% or higher. The preferred buffer is phosphate buffered saline (PBS) because it is relatively inexpensive and reliable, although a number of other buffers may be employed. Typical of the well known buffers which may be employed in this invention are borate, glycine, pyrophosphate and imidazole buffers. In a typical procedure for the detection of antibodies: 0.1 ml of phosphate buffered saline, pH 7.2; 5 .mu.l of serum; 30 .mu.l of sheep anti-human IgG (Meloy Labs., 6.4 mg antibody/ml); 10 to 20 .mu.l of .sup.125 I-labelled GC-antigen (3000-5000 cpm ) are mixed as described above. Even less than 5 .mu.l of serum can be used, provided the amount of anti-human IgG added is adjusted to yield maximal precipitation of radioactivity. The antigenantibody reaction mixture is incubated at 45.degree. for 2 hours and at the end of this period 0.50 ml of PBS was added. The PBS may be omitted, but is used to provide a larger volume of material to facilitate handling. The suspension is filtered through a 2.4-cm Whatman GF/C filter using a pyrex microanalysis filter apparatus. The filter is prewashed to minimize nonspecific binding of antigen. The preferred prewash medium is bovine serum albumin although other reagents such as human serum immunoglobulin, ovalbumin and hemoglobin may also be employed. The preferred prewash is with 0.5 ml of a solution containing 2% by weight fraction V BSA together with a chelating agent such as 0.01 M ethylenediamine tetraacetic acid (EDTA). After filtration, the precipitate is washed thoroughly with water. The radioactivity of the precipitate is then determined by any convenient method, for example a gamma spectrometer. Blank reactions, which contain all of the components of the reaction media except the serum, are also counted. These are subtracted from the results obtained with positive and negative sera. This procedure serves to reduce proportionately the low level of radioactivity fixed by the negative sera since the blank values often amount to half the count incorporated by the negative sera. The filter procedure just described, while perfectly adequate for many purposes, is not preferred for large scale population screening. For this purpose, the centrifugation procedure is preferred. The incubation procedure employed is similar to the procedure utilized with the filter procedure except that the buffer contains a reagent to eliminate non-specific binding of the antigen. The reagent performs the same function in the incubation medium as it does in the filter procedure for washing the filter. The same reagents as mentioned above can be employed, and again BSA is preferred. A typical incubation medium contains 0.2 ml of PBS containing 2% by weight BSA, 0.02 M EDTA or other chelating agent; 5 .mu.l of serum; 30 .mu.l of sheep anti-human IgG and 10 to 20 .mu.l of .sup.125 I labelled antigen. Following incubation of the typical incubation medium, 3 ml of PBS are added to the reaction mixture which is then centrifuged at from about 2000 to 3000xg. The supernatant fractions are discarded and the centrifugation tube again washed with 3 ml of PBS and recentrifuged. The supernatant is discarded and the precipitate counted, for example with a gamma counter. Of course, as in the filter procedure, other buffers can be employed in the centrifugation process. In both procedures the chelating agent can be omitted. While the procedure has been described with .sup.125 I as the detectable element, others may also be utilized, for example .sup.14 C-acetic anhydride, maleic anhydride, fluorodinitro benzene, fluorescein, and isothiocyanate; .sup.32 P-diisopropylfluorophosphate; and .sup.35 S phenylisothiocyanate. The preferred detectable element is .sup.125 I because a scintillation solution is not required if it is used in a gamma ray spectrometer, and it is a weak enough gamma emitter with a sufficiently short half life to obviate much of the hazzard of working with it. A comparison of the reactivity of known positive and negative sera using the filter assay procedure is presented in FIG. 1 and as indicated, the reaction is directly proportional to the quantity of antigen added. Depending on the antigen preparation and the quantity of gonococcal antibodies in the sera used, the ratio of labeled antigen fixed by positive sera to that of negative sera may vary from 10/1 to 30/1. It is important, although not essential, to add the GC-antigen to each sample at about the same time, that is within about 2 minutes following the sheep anti-human IgG because the extent of antigen precipitation is related to its time of addition. Thus, is added 60 min after the sheep anti-human IgG, antigen fixation is reduced by almost half. In contrast, if the antigen is added to negative sera just prior to the anti-human IgG, excessively high values are obtained which in effect reduces the positive to negative ratio to about 3 to 1. However, these factors can be compensated for if for some reason it is desirable or necessary to withhold prompt addition of the GC-antigen. Normally duplicate reactions containing no more than 3000 to 6500 cpm of labelled GC-antigen are adequate to distinguish between positive and negative sera. Comparisons are made with blanks or with negative pools or sera. The optimum procedure is to prepare a titration curve similar to FIG. 1. Usually a serum may be considered positive if it fixes three times the level of antigen fixed by a negative pool. To establish the sensitivity and specificity of this method, 152 sera (57 men and 95 women) were examined in a double-blind study. Only sera from patients with a bacteriologically confirmed diagnosis of gonorrhea were considered positive, while the negative controls were obtained from individuals with negative-bacteriological and clinical findings. As indicated in Table 1, the process of this invention provides a high degree of reliability in detecting gonorrhea in males and females, Thus, it was possible to correctly identify 87% of the infected men and 88% of the infected women. False positives were encountered in only three cases. Included in the test were 20 duplicates and 2 triplicates, and in no instance was there a discrepancy among these results. The inability to detect positive cases in some instances is not surprising, since antibody titers may not have reached detectable levels at the time the serum samples were taken. TABLE 1 ______________________________________ COMPARISON OF CULTURE AND CASE HISTORY DIAGNOSES FOR GONORRHEA WITH THE RADIOIMMUNE ASSAY Determined Positive Determined Negative History and Sex Culture RIA Percent Culture RIA Percent ______________________________________ Male 38 33 87 19 17 90 Female 60 53 88 35 34 97 ______________________________________
	description	This application is a continuation of U.S. application Ser. No. 16/688,979, filed on Nov. 19, 2019, which claims the benefit of, and priority to, U.S. Provisional Application No. 62/770,125, filed on Nov. 20, 2018. All of the above applications are hereby incorporated herein by reference in their entirety. This disclosure relates generally to mobile radiation oncology coach system and more specifically to a mobile radiation oncology coach system with internal and/or external shielding to a mobile unit. A medical linear particle accelerator (LINAC) is widely used to treat cancer by using customized high energy x-rays or electrons to conform to a tumor's shape of a patient and destroy cancer cells while sparing surrounding normal tissue of the patient. Like all expensive equipment, a LINAC with normal usage (e.g., 25 treatments per day) would require regular maintenances in addition to daily or weekly-based calibrations. Typically, a regular maintenance would require the LINAC to be shut down for a period of time that may takes weeks or months. In addition, when an upgrade for renovation or when new equipment installation is required, the LINAC is typically shut down. The shutdown of a single vault LINAC facility could cost a million dollars of revenue lost during a multi-month shutdown. The inventors here have recognized that there is a need for mobile and/or interim (e.g., portable, substantially portable/movable, leasing) radiation oncology service solutions that are capable of overcoming the foregoing shortcomings and maintain high-quality care, referrals and revenue while the fixed site equipment is temporarily unavailable or where fixed site equipment are not possible. Disclosed here are numerous aspects of a unique and advantageous mobile radiation oncology coach equipped with state-of-the-art LINAC facility that is able to provide the same or equivalent technology, such as accelerated treatment times, a six-point safety system, ergonomic operator controls and many patient-friendly features, that are typically offered to patients in leading cancer centers. While patients receive excellent clinical care, the user and/or owners of the mobile radiation oncology coach experience no disruption in referrals, revenue or staffing during equipment upgrades or construction projects. In some embodiments, a mobile radiation oncology coach system comprises a trailer configured to include a control console area, a treatment area, and a vestibule area located between the control console area and the treatment area, the treatment area being equipped with a medical treatment facility that can emit radiation; a first internal shielding provided between the vestibule area and the treatment area; a first door configured and providing access between the treatment area and the vestibule area, the first door including a first supplemental shielding; and a second door configured and providing access between the vestibule area and the control console area, the second door including second supplemental shielding and further configured to be constructed near an opposite side of said trailer, preventing a direct line of sight between the treatment area and the control console area. In some embodiments, the first internal shielding comprises interlocked lead bricks. In some embodiments, the interlocked lead bricks comprises a predetermined thickness to provide substantially effective shielding between the control console area and the treatment area. In some embodiments, the mobile radiation oncology coach system further comprises a second internal shielding provided between the vestibule area and the control console area. In some embodiments, the second internal shielding comprises additional interlocked lead bricks comprising a second thickness to provide substantially effective shielding between the control console area and the vestibule area. In some embodiments, the mobile radiation oncology coach system further comprises an alternating door containing interlocked lead bricks to shield direct line of sight of the medical treatment facility and people located in the control console area. In some embodiments, the medical treatment facility includes medical linear particle accelerator (LINAC). In some embodiments, the mobile radiation oncology coach system further comprises an external shielding, wherein the external shielding comprising a plurality of barriers. In some embodiments, the plurality of barriers are made of concrete. In some embodiments, the mobile radiation oncology coach system further comprises a support pad dimensioned to support the trailer, and wherein the support pad comprises concrete. In some embodiments, the mobile radiation oncology coach system further comprises a tractor, wherein said tractor and said trailer are arranged in tandem. In some embodiments, the first door is a pocket door that is driven by a motor which in turn is controlled by door switches. In some embodiments, the mobile radiation oncology coach system further comprises a lever for manually disengaging the pocket door and the motor. In some embodiments, a mobile radiation oncology coach system comprises a trailer configured to include a control console area and a treatment area, the treatment area being equipped with a medical treatment facility that can emit radiation; a first internal shielding disposed between the control console area and the treatment area; a first door configured and providing access between the treatment area and the control console area, the first door including a first supplemental shielding, wherein the first door is further configured to be constructed and positioned to prevent a direct line of sight between the treatment area and the control console area; and a swing door including second supplemental shielding, and constructed and positioned to shield radiation that may be emitted in an area associated with the first door between the treatment area and the control console area. In some embodiments, the first internal shielding comprises interlocked lead bricks. In some embodiments, the interlocked lead bricks comprises a predetermined thickness to provide substantially effective shielding between the control console area and the treatment area. In some embodiments, the mobile radiation oncology coach system further comprises a vestibule area located between the control console area and the treatment room; and a second internal shielding provided between the vestibule area and the control console area. In some embodiments, the second internal shielding comprises additional interlocked lead bricks comprising a second thickness to provide substantially effective shielding between the control console area and the vestibule area. In some embodiments, the medical treatment facility includes medical linear particle accelerator (LINAC). In some embodiments, the mobile radiation oncology coach system further comprises an external shielding, wherein the external shielding comprising a plurality of barriers. In some embodiments, the plurality of barriers are made of concrete. In some embodiments, the mobile radiation oncology coach system further comprises a support pad dimensioned to support the trailer, and wherein the support pad comprises concrete. In some embodiments, a mobile radiation oncology coach system comprises a trailer configured to include a control console area and a treatment area, the treatment area being equipped with a medical treatment facility that can emit radiation; internal shielding disposed between the control console area and the treatment area; and external shielding provided at a predetermined location outside of the trailer. In some embodiments, the internal shielding comprises interlocked lead bricks. In some embodiments, the interlocked lead bricks comprises a predetermined thickness to provide substantially effective shielding between the control console area and the treatment area. In some embodiments, the mobile radiation oncology coach system further comprises a vestibule area located between the control console area and the treatment room; and a second internal shielding provided between the vestibule area and the control console area. In some embodiments, the second internal shielding comprises additional interlocked lead bricks comprising a second thickness to provide substantially effective shielding between the control console area and the vestibule area. In some embodiments, the mobile radiation oncology coach system further comprises an alternating door between the treatment room and the control console area, wherein the alternating door contains interlocked lead bricks to shield direct line of sight of the medical treatment facility and people located in the control console area. In some embodiments, the mobile radiation oncology coach system further comprises a first door configured and providing access between the treatment area and the vestibule area, the first door including first shielding; and a second door configured and providing access between the vestibule area and the control console area, the second door is further configured to be constructed near an opposite side of said trailer, preventing a direct line of sight between the treatment area and the control console area. In some embodiments, the mobile radiation oncology coach system further comprises a first door configured and providing access between the treatment area and the control console area, the first door including first supplemental shielding. In some embodiments, the first door is further configured to be constructed and positioned to prevent a direct line of sight between the treatment area and the control console area. In some embodiments, the mobile radiation oncology coach system further comprises a swing door including a second supplemental shielding, and constructed and positioned to shield radiation that may be emitted in an area associated with the first door between the treatment area and the control console area. In some embodiments, the medical treatment facility includes medical linear particle accelerator (LINAC). In some embodiments, the external shielding comprising a plurality of barriers. In some embodiments, the plurality of barriers are made of concrete. In some embodiments, the mobile radiation oncology coach system further comprises a support pad dimensioned to support the trailer, and wherein the support pad comprises concrete. In some embodiments, the mobile radiation oncology coach system further comprises a tractor, and wherein said tractor and said trailer are arranged in tandem. In some embodiments, a method for providing a mobile radiation oncology services, the method comprises moving a trailer to a designated site, the trailer having a control console area and a treatment area being equipped with a medical treatment facility that can emit radiation; providing an internal shielding disposed between the control console area and the treatment area; and providing an external shielding at a predetermined location outside of the trailer. In some embodiments, the internal shielding comprising interlocked lead bricks. In some embodiments, the method further comprises providing an alternating door positioned between the treatment area and the control console area, wherein the alternating door contains interlocked lead bricks to take away direct line of sight of the medical treatment facility and people located in the control console area. In some embodiments, the medical treatment facility is a LINAC. In some embodiments, the external shielding comprising a plurality of barriers. In some embodiments, the plurality of barriers is made of concrete. In some embodiments, the method further comprises providing a support pad dimensioned to support the trailer, wherein the support pad is made of concrete. In some embodiments, the method further comprises providing a tractor, wherein the tractor and the trailer are arranged in tandem. In some embodiments, the method further comprises securing the trailer after the trailer is moved to the designated site. In some embodiments, the method further comprises removing the external shielding after the services is complete. It should be understood that each of the foregoing and various aspects, together with those set forth in the claims and summarized above and/or otherwise disclosed herein, including the drawings, may be combined to support claims for a device, apparatus, system, method of manufacture, and/or use without limitation. As summarized above and illustrated in the drawings, disclosed herein are various aspects and embodiments of a mobile radiation oncology coach system. According to some embodiments, the exemplary mobile radiation oncology coach system 10 described herein comprises a mobile unit 100, an external shielding 201-211 and an optional support pad 300. Referring to FIG. 1, the mobile unit 100 has a tractor 110 and a trailer or relocatable coach 120 arranged in tandem. The trailer 120 can be attached to the tractor 110 during relocation (travel mode). The trailer 120 is configured to house a LINAC facility. When the trailer 120 is in the treatment configuration or clinical mode, the trailer 120 can be detached from the tractor 110 so that the tractor 110 can be separated from the trailer 120 for other duties. In some embodiments, the mobile unit 100 can be a single motorized vehicle (e.g., a bus or a motorhome) instead of a separate tractor and trailer combination. In the exemplary embodiment, the mobile trailer 120 is about 58 feet in length and about 13 feet 6 inches in height. When the mobile trailer 120 is in the travel mode, the mobile trailer 120 is about 10 feet in width. In the exemplary embodiment, the mobile trailer 120 has slide-out sections that allow the width of the mobile trailer 120 to be extended to a wingspan of about 18 feet in width when the mobile unit 100 is in the clinical mode. In some embodiments, the dimensions of the mobile trailer 120 are varied, including the dimensions of the slide-out sections. Preferably, the mobile trailer 120 is provided with sufficient area to be maneuvered and positioned for setup and takedown. The mobile trailer 120 can be provided with external storage compartments and service doors that require access during processes or operation. The slide-out sections, patient lift, entry stair and any optional platform may require additional space on the passenger side of the mobile unit 100. In some embodiments, storage compartments, service doors, slide out sections, patient lift and/or platforms are provided in alternative configurations. Referring also to FIG. 2, proper and safe operation of the LINAC system can be obtained when the mobile trailer 120 is located on a substantially level area or firm pad 300. Hydraulic support legs 180 can be provided to assist in the leveling and stabilization of the mobile trailer 120. In some embodiments, load bearing screw jacks and support legs can ultimately replace the hydraulic support legs as long-term support. In some embodiments, the recommended mobile unit support pad 300 is a concrete pad with a dimension of, for example, 20 feet wide and 60 feet long. In some embodiments, the minimum support pad 300 could be split into two or more separate pads, rather than one large pad if properly configured. For example, a support pad 300 at the front 122 of the mobile trailer 120 can provide support for the landing gear, leveling legs and king pin support. A support pad at the rear 124 of the mobile trailer 120 can support tandem-axles (two sets of axles) 190, the hydraulic leveling legs and the load bearing screw jacks. Referring also to FIG. 12, in some embodiments, the thickness of support pad 300 is to be determined at the local level, based on, for example, soil conditions. In some embodiments, the levelness of support pad 300 is preferably not to exceed ¼ inches per 10 feet. In some embodiments, the overall length of the mobile unit 100 of the tractor and trailer tandem is generally 75 feet. The travel weight can be approximately 80,000 pounds. In some embodiments, an area, for example, one hundred sixty feet by 60 feet immediately adjacent to the support pad 300 on both sides is blocked off and reserved to allow for assembly, set-up, and upon conclusion of its use, dismantling of this unit. Access to this area from the adjacent roadway infrastructure preferably be available in all weather conditions, while taking into consideration the weight of the trailer and supporting vehicles. Exemplary electrical options are provided below. The electrical power for the mobile unit 100 can be 480 volt AC, 3-phase Wye system with neutral and ground, at 200 Amperes. The frequency can be 60+/−2 Hertz. The maximum voltage variance can be +11%/−4% from nominal voltage. The maximum line regulation can be 2.5%. The maximum line-to-line imbalance can be 3%. For power cord/plug, a Russell Stoll 200 Amp plug, can be supplied with the 50 feet power cord for connection to facility power. The cord connection point can be on the roadside of the trailer at around mid-point. For electrical support requited at the facility, a 200 Amp, 480 Volt, 5 wire dedicated service including, for example, a Russell Stoll 200 Amp receptacle, can be mounted in a NEMA 3R rated enclosure to meet local codes requirements. An auxiliary earth ground connection point may be required in addition to the ground circuit within the pin and sleeve connector. An easily accessible NEMA 3R service disconnect in the immediate area is preferable. The ground for the mobile unit 100 can be, for example, originated at the system power source, e.g., transformer or first access point of power into a facility, and be continuous to the system power disconnect on the mobile trailer 120. This ground can be spliced with high compression fittings and can be terminated at each distribution panel it passes through. When it is broken for a connection to a panel, it can be connected into an approved grounding block with the incoming and outgoing ground in this same grounding block, which then can be connected to the steel panel. The connection at the power source can be at the grounding point of the neutral—ground if a Wye transformer is used. In the case of an external facility, it can be bonded to the facility ground point at the service entrance. In some embodiments, the ground wire can generally be copper wire with a minimum AWG 1/0 or the same size as the power feeders, whichever is larger. This means that if there is a primary feeder to a distribution panel of 500 MCM with a secondary feeder to this system of AWG 1/0 wire, the ground to the distribution panel can be 500 MCM with an AWG 1/0 to the system. The ground wire impedance from the system disconnect, including the ground rod, preferably not have an impedance greater than 2 ohms to earth as measured by one of the applicable techniques, for example, ANSI/IEEE Standard 142-1982. In some embodiments, a 15 feet ground cable can be pre-installed and can be found in the forward most, entry door side of the mobile trailer. In some embodiments, a grounding rod is provided and installed as part of the system installation. When the mobile unit 100 is generating radiation for either imaging or treatment, an exclusion zone is generally required to prevent exposure to either radiation workers or members of the public. This exclusion zone is generally determined based on the level of radiation exposure and local, state and federal requirements. It is possible to add shielding that allows a building to be closer, but the distances allowed may be determined by the customer's physicist and local, state and federal requirements. FIGS. 13-18 depict diagrams of exemplary radiation scatter and leakage measurements conducted on the mobile unit 100 of FIG. 1. In some embodiments, measurements can be acquired by using a PTW Unidos E electrometer and a PTW TK-30 large volume chamber. Measurements can be engaged at different field sizes (FS) and gantry angles (G). Leakage measurements can be engaged with the multileaf collimator completely closed (or field size of 0 cm×0 cm). Full scatter measurements can be produced with the collimator in the full open position (or 28 cm×28 cm). All measurements can be displayed as a percentage of the delivered dose at isocenter. All displayed data are at the level of isocenter and radiate out at 1 m increments at various angles from zero degrees to 360 degrees. Based on the exemplary measurements and calculations, expected radiation exposure results for the mobile unit 100 are provided in this disclosure and the above-mentioned distances are exemplary recommendations. The final site plan may also be determined based on distances to adjacent buildings and structures. In addition, as with the installation of any ionizing radiation device, the appropriate site radiation survey should be conducted to verify compliance with these recommendations. Failure to correctly calculate and construct the radiation barriers and shielding as required may result in radiation exposure levels that are in excess of allowable limits, and may present hazards to radiation workers and members of the public. In some embodiments, 6-10 anchoring points embedded in the support pad 300 are provided. In some embodiments, it is preferable that a minimum of 6 anchor points be used. See FIG. 12 for a typical pad layout and typical tie down. Actual thickness of the support pad 300 can be based on, for example, site conditions, coach weight distribution, and other factors. More or less anchoring points can optionally be used. A typical LINAC system uses a 6 MV FFF beam. The maximum dose rate can be 800 cGy/min. The maximum treatment field can be 28 cm×28 cm. The isocenter can be 100 cm. The unit can employ a beam stop so that the primary consideration for shielding is leakage and scatter. A typical LINAC system can deliver 3D, IMRT, and VMAT treatments. Shielding considerations for the mobile radiation oncology coach system 10 can have the following exemplary assumptions: workload, use factors (U=1), occupancy times, design goal (permissible limits), distances, and utilization rate (beam on time). These considerations allow many variants to the external shielding design of the mobile radiation oncology coach system 10. Design goals for unrestricted areas can be set as 1 mSv/yr (0.02 mSv/wk). Design goals for restricted areas can be set as 5 mSv/yr (0.10 mSv/wk). The conventional exposure rate in any one hour of 2 mR/hr guideline can be used. In addition, occupancy factors and utilization rate can be considered. In addition, actual instantaneous dose rates may optionally be considered as well. The following lists an exemplary series of iso-scatter/leakage measurements (see FIGS. 13-18) for calculating shielding requirements. As a guideline, the following parameters were used to calculate the required shielding. ParametersValueWorkload1,200,000 mGy/wk (based on a workload of 40 patients perday)Use Factor1.0 (leakage and scatter)OccupancyBased on locationDistancesMeasured in meters with 0.3 meter from barrierDesign Goal1 mSv/year (unrestricted), 5 mSv/year (restricted)IMRT4 (used for workload leakage) Referring to FIGS. 2-3, the mobile trailer 120 has a front end 122 and a rear end 124. Between the front end 122 and rear end 124, the interior space of the coach 120 can be partitioned into multiple rooms. In some embodiments, as shown in FIGS. 2-3, the coach 120 includes a control console room or area 130, a vestibule 140, and a treatment room or area 150. As shown in FIGS. 2-3, the treatment room 150 is closer to the rear end 124 than the vestibule 140 and the control console room 130 while the vestibule 140 is closer to the rear end 124 than the control console room 130. In some embodiments, other partitions or arrangements for the rooms/areas 130, 140, 150 can be provided. For example, in some embodiments, only the treatment room 150 and control console area 130 are partitioned. In other embodiments, only the treatment room 150 is provided in the coach 120 and the functions of the control console room can be provided outside of the coach 120 via, for example, wired or wireless communications. In some embodiments, the control console room 130 can contain the operator's station and the planning station. The control console room 130 can also be an entry room and has a front door 132 for entering and exiting the coach 120. A stair 134 can be provided to facilitate the access. In some embodiments, the control console area 130 has an access door 136 for connecting the control console area 130 and the vestibule 140. In some embodiments, a door 142, for example a sliding door, is provided for connecting the vestibule 140 and the treatment room 150. The sliding door 142 can slide into wall 148. The sliding door 142 can be loaded with lead bricks to form a pocket door. In one embodiment, the pocket door 142 can weight about 5000 lbs. Referring also to FIGS. 8A-8C, in some embodiments, through an engagement mechanism 151, the sliding door 142 can be mechanically driven by a drive chain 147 that is engaged with a motor 141. The motor 141 can be controlled by door switches 145 from the treatment room 150 and switches (not shown) from the vestibule 140. A track or rail 149 can be installed at an upper location of the sliding door 142 to accept one or more wheels 155 that are coupled to the sliding door 142 through a supporting mechanism 153. Additional wheels can be provided at the bottom of the sliding door 142 to facilitate the sliding of the door 142 on a bottom track or rail provided on the floor between the vestibule 140 and the treatment room 150. In one embodiment, the track or rail is provided as recessed in the floor about ½ inches. A lever 143 can be provided for manually disengaging the sliding door 142 and the motor 141 so that and the sliding door 142 can be open/close manually from the treatment room 150, for example, in case of an emergency. Referring also to FIG. 9, in some embodiments, the vestibule 140 has a swing door 144 which is preferably closed for the treatment to be delivered. One or more interlock switches 157 can be installed for redundancy and fail safe to insure the swing door 144 is shut during treatment delivery. The vestibule 140 can be provided with a door 146 that can be used as the primary entrance or for use with the wheelchair lift. A patient under treatment can also enter the coach 120 from the front door 132. After confirmed by a representative of the control console room 130, the patient can enter the vestibule 140 through the access door 136. Then the patient can be guided to the treatment room 150 for treatment through the pocket door 142. In some embodiments, the treatment room 150 can be designed for installation of a LINAC system 152 or other treatment or diagnostic instrument(s). A LINAC system 152 generally uses microwave technology to accelerate electrons in a wave guide and enable these electrons to collide with a heavy metal target to produce high-energy x-rays. These high energy x-rays can be shaped as they exit the machine to conform to the shape of the patient's tumor, enabling the customized beam can be directed to the patient's tumor. The x-ray beam comes out of a part of the accelerator called a gantry 154, which can be rotated around the patient. Radiation can be delivered to the tumor from many angles by rotating the gantry 154 and moving the treatment couch 156. Because radiation may scatter or leak from the treatment room 150 during a patient's treatment, protection to people outside of the treatment room 150 is desired. In some embodiments, the coach 120 can have shielding for protecting the control console area 130 during treatment operations. In some embodiments, lead (Pb) shielding 160, for example interlocked lead bricks, is used in walls 138, 148 and doors 142, 144 to block line of site of leakage and scatter. In other embodiments, standard shielding materials can be used. The wall 138 between the vestibule 140 and the control console room 130 can provide secondary or additional shielding for protecting the control console area 130. Referring to FIGS. 5-7, internal lead shielding formed by interlocked lead bricks 160 is applied to the wall 148 and doors 142, 144. The actual thickness of the interior walls and doors are determined based on standard techniques. In some embodiments, using standard lead (Pb) shielding materials, the thickness of lead bricks on the interior wall 138 between the control console room 130 and the vestibule 140 is 2 inches, the thickness of lead bricks on the interior wall 148 between the vestibule 140 and the treatment room 150 is 4 inches, the thickness of lead bricks on the pocket door is 2 inches, and the thickness of lead bricks on the swing door is 2 inches. In some embodiments, the access door 136 between the control console room 130 and the vestibule 140 can be made without shielding and is there for privacy purposes only. Alternatively, the access door 136 can be provided with shielding if necessary. In some embodiments, different thicknesses of the shielding can be used based on different shielding materials and/or radiation scatter and/or leakage. In some embodiments, the pocket door 142 between the vestibule 140 and the treatment room 150 can be a steel door with 2 inches of lead bricks. The steel plates holding the lead in place can be ¼ inches steel or ½ inches steel. In some embodiments, the coach 120 advantageously incorporates alternating doors between the treatment room 150, vestibule 140 and control console room 130 to provide effective shielding. For example, a manual swing door 144 can be added. The manual swing door 144 can contain 2 inches of interlocked lead bricks 160 to take away any potentially not blocked direct line of sight of the machine 154 and those located in the console area. In some embodiments, non-manual or automated doors may optionally be used. In some embodiments, the internal shielding 160 is installed after the trailer 120 has arrived at a designated site. In this configuration, the mobile unit 100 can meet the highway weight limitations set forth by the state authorities. A forklift (not shown) may be utilized to unload the lead shielding 160 (and other accessories) from a secondary vehicle. If a forklift is needed, a site survey may be conducted to determine the size of the forklift prior to the trailer's arrival. Alternatively, the internal shielding 160 is installed before the trailer 120 arrives at the designated site. In this configuration, the mobile unit 100 can be ready for used in a timely manner. In some embodiments, coach 120 is equipped with limited yet adequate internal shielding 160 so as to achieve energy efficiency for relocation of the coach 120 to a designated site. The protection of the public external to the coach 120 is achieved using external shielding provided on the outside of the coach 120. In some embodiments, concrete or high-density concrete for the external shielding is used surrounding the coach 120. The amount of external shielding required can be dependent on, for example, one or more or all of the following factors: workload, distance to surrounding areas, occupancy of surrounding areas, height of surrounding buildings, density of concrete used for shielding, and/or barrier location. The external shielding may be customized and does not need to be symmetric depending on the above listed parameters. The closer the coach 120 is placed to an existing occupied structure, the more shielding will generally be required. In some typical examples, the mobile radiation oncology coach system workload stays fairly constant (35-40 patients per day). The radiation decreases by 1/R2, where R is the distance from the radiation source. In other words, when the distance from the radiation source is doubled, the radiation exposure decreases by approximately ¼. Occupancy Rate (T) can be determined by how often someone will be in a certain area. If people are in an area 100% of the time (T=1) the machine is on, then that area must be shielded as needed/appropriately. If a person is in an area where there is little to no occupancy and no direct line of sight to the particle accelerator, in theory, that area would not need as much shielding. If there are multi-story structures, then that can be taken into account as well in determining the appropriate shielding. In some embodiments, the following external shielding recommendation is based on the following: ParametersValueDesign Goal0.02 mGy/wk (unrestricted)Workload1,200,000 mGy/wkLeakage0.05%Occupancy RateT = 0.5 and T = 1.0ShieldingHigh-Density Concrete (240 pcf) On leakage parameter, Federal regulations require that radiation producing machines cannot exceed 0.1% of the output at 1 meter from the radiation source. Many existing machines are able to achieve 0.05% of the calibrated output at 1 meter. From the measurements depicted in FIGS. 13-18, the leakage parameter may be even less than 0.05%. For the shielding parameter, in some embodiments, concrete of around 147 pcf is used to achieve more cost effective result for adequate shielding. FIG. 10 depicts a top view of the trailer 120 of the mobile unit 100 illustrated in FIG. 1, with external shielding barrier 201-211 positioned according to some embodiments. The trailer or coach 120 illustrated in FIG. 10 is in a clinic mode. As shown in FIG. 10, each of the external shielding barriers or walls 201-211 is placed at a calculated and/or predetermined distance from the nearest surface of coach 120. In some embodiments, the calculated distance is 3 meters. In some embodiments, at least 1 meter is disposed between the furthest out wall and the shielding to account for room to maneuver around the unit when parked. FIG. 11 is table showing exemplary recommended thickness (in inches, when Occupancy Rate T=0.5 and T=1.0, respectively) for each external shielding barrier 201-211 identified in FIG. 10. As depicted in FIG. 11, barrier 210 is thicker than barrier 211 although both barrier 210 and barrier 211 are placed on relatively symmetrical positions. In consideration of the position of the pocket door 142, it is preferable to have the barrier 210 thick enough to prevent or reduce any potential radiation leaked through the pocket door 142 or the surrounding of the pocket door 142. In other embodiments, barrier 210 and barrier 211 can have the same thickness or other thicknesses. The height of the external shielding walls 201-211 is dependent on location of nearby structures. This will be different on each location the unit is placed. The height of the external barriers 201-211 is configured to block a direct line of sight of the leakage coming from any gantry position. Alternative thicknesses, heights and/or materials may optionally be used to accomplish similar shielding results. In the present embodiment, the ceiling of coach 120 is not shielded. Alternatively, the coach 120 can also include shielding in the ceiling. This may help to reduce the shielding height and thickness of the external shielding barriers 201-211. Skyshine can be evaluated as needed. In the present embodiment, shielding below the trailer 120 is not required for lateral barriers and for the rear of the trailer 120. The external barriers 201-211 will block any ground scatter. Alternatively, shielding below the trailer between the tractor 110 and the control console area 130 can be provided. In some embodiments, sand is used to provide such shielding. The amount of sand can be range from 30″ to 36″. In some embodiments, external shielding 201-211 may require using L-block shields where the external shield abuts with the trailer 120. This is to ensure there are no areas of leakage. The x-ray radiation generated by the mobile unit 100 is typically 6 MV. It is typically when about 10 MV that pair production is achieved and elements become radioactive. As concrete is a low Z-element, even at high energy levels, advantageously no radioactive material is created. Accordingly, all external shielding barriers 201-211 will not be contaminated after used. In some embodiments, external shielding barriers 201-211 can be removed from site after use and can be reused. A full radiation survey can be conducted around the trailer 120 after installation. Any areas that exceed limits for unrestricted areas will be marked as restricted areas. These areas may not be occupied by members of the general public, and any professionals working in these areas may be permitted based on training and being equipped with the appropriate monitoring badge (personal monitor). Areas that have no occupancy may require little to no shielding. These areas can preferably be treated as restricted and access to these areas may be limited. Fences and appropriate signage may be required. These areas are preferably monitored closely by the staff and security. It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the invention be regarded as including equivalent constructions/processes to those described herein insofar as they do not depart from the spirit and scope of the present invention. For example, the specific sequence of any described component and/or process may be altered. For example, certain processes are conducted in parallel or independent, with other processes, to the extent that the processes are not dependent upon each other. Other alterations or modifications of the above components and/or processes are also contemplated. For example, further insubstantial changes to the components, systems and/or processes are also considered within the scope of the processes described herein. In addition, features illustrated or described as part of one embodiment can be used on other embodiments to yield a still further embodiment. Additionally, certain features may be interchanged with similar devices or features which perform the same or similar functions. It is therefore intended that such modifications and variations are included within the totality of the present invention. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The term “consisting essentially of” to describe a combination shall include the elements, ingredients, components or steps identified, and such other elements ingredients, components or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, ingredients, components or steps herein also contemplates embodiments that consist essentially of the elements, ingredients, components or steps. By use of the term “may” herein, it is intended that any described attributes that “may” be included are optional. By use of the term “at least one of A and B” herein, it is intended to mean “one or more of X and/or Y.” Plural elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate plural elements, ingredients, components or steps. The disclosure of “a” or “one” to describe an element, ingredient, component or step is not intended to foreclose additional elements, ingredients, components or steps. The detailed description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practice the invention. Thus, the detailed descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Modifications and variations of the above detailed description are considered within the scope of the described invention. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, they thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.
	summary
	claims	1. An imaging system, including:a rotating gantry with an examination region in which a volume of interest (VOI) is positioned;a transmission X-ray source, mounted for rotation with the gantry, the X-ray beam emitted across the examination region to an X-ray detector; anda movable wedge-shaped attenuation filter comprising a first lateral portion having a first thickness exposed to the X-ray beam, a second lateral portion having a second thickness exposed to the X-ray beam wherein the first thickness is greater than the second thickness, and a middle portion extending from the first lateral portion to the second lateral portion and having a thickness exposed to the X-ray beam which continually decreases from the first thickness to the second thickness,wherein the filter is positioned between the X-ray source and the examination region, for the filter being at least laterally movable relative to the X-ray beam to adjust an attenuation of the X-ray beam across an entire lateral extent of the X-ray beam between the first lateral portion and the second lateral portion of the filter. 2. The system according to claim 1, wherein the X-ray source generates a half field of view across the VOI and generates a complementary half field of view when the gantry is rotated 180°. 3. The system according to claim 1, wherein the wedge-shaped attenuation filter is movable, closer to or further from the X-ray source. 4. The system according to claim 1, wherein the X-ray detector is a flat panel X-ray detector, and wherein the gantry rotates 360° to generate a complete set of X-ray data for the VOI during computed tomography (CT) acquisition. 5. The system according to claim 4, further comprising an overlap analyzer that compensates for redundant data collected along redundant rays during the 360° rotation of the gantry to refine the X-ray data. 6. The system according to claim 5, further comprising a reconstruction processor that reconstructs a CT image of the VOI from the refined X-ray data. 7. The system according to claim 1, further including a wedge position calculator that determines path length and density information encountered by the X-ray beam at each rotational position of the X-ray source. 8. The system according to claim 7, further comprising a controller that receives path length and density information in real time and adjusts the position of the wedge-shaped attenuation filter during rotation. 9. The system according to claim 8, wherein the wedge position calculator calculates wedge position as a function of X-ray gain detected at the detector, and path length and density information. 10. The system according to claim 1, wherein the wedge-shaped attenuation filter has a rectangular base, two opposite triangular sides that connect to the base and taper to an edge opposite the base, and two rectangular sides that connect to the base and the edge opposite the base. 11. The system according to claim 1, further including at least two nuclear detector heads movably mounted to the gantry, wherein the nuclear detector heads are at least one of positron emission tomography (PET) detector heads or single-photon emission computed tomography (SPECT) detector heads. 12. The system according to claim 1, wherein the X-ray source is a cone-beam X-ray source. 13. The system according to claim 1, wherein the wedge-shaped attenuation filter has at least one of the following configurations:a base with a pseudo-bow-tie shape, coupled to a top surface with a substantially central crease running the length thereof to an edge that is common to a bottom surface;a rectangular base that is coupled to curved top and bottom surfaces that meet at a common edge; ora dual-wedge arrangement, wherein a first wedge and a second wedge are slidably and adjustably coupled to each other. 14. A method of performing a CT scan using the imaging system of claim 1, including:determining shape, size, and density information for the VOI in the examination region;positioning the wedge-shaped attenuation filter at a position in front of the X-ray source in accordance with gain of the detector and the shape, size and density information; andinitiating CT data acquisition and gantry rotation. 15. The method according to claim 14, further including adjusting the position of the wedge-shaped attenuation filter relative to the X-ray source to maintain relatively uniform attenuation of X-rays as the gantry rotates around the VOI. 16. A method of generating a 3D image of a subject, including:evaluating a VOI in an examination region of an X-ray imaging device to determine size, shape, and density information about a portion of the VOI in the examination region;positioning an adjustable wedge-shaped attenuation filter at a position in a cone-shaped X-ray beam, the wedge-shaped attenuation filter being movable in front of the X-ray source, such that a first lateral portion of the filter has a first thickness exposed to the X-ray beam, and a second lateral portion of the filter has a second thickness exposed to the X-ray beam, wherein the first thickness is greater than the second thickness, and such that a middle portion of the filter extends from the first lateral portion to the second lateral portion and has a thickness exposed to the X-ray beam which continually decreases from the first thickness to the second thickness, and an entire lateral extent of the X-ray beam is disposed between the first lateral portion and the second lateral portion; andinitiating CT data acquisition and gantry rotation. 17. The method according to claim 16, further including adjusting the position of the wedge-shaped attenuation filter relative to the X-ray source to maintain relatively uniform line integrals for X-ray paths through the VOI as the gantry rotates around the VOI. 18. The method according to claim 17, further including adjusting the position of the wedge-shaped attenuation filter closer to or further from the X-ray source. 19. The method according to claim 16, further including:converting X-rays that have traversed the VOI into imaging data; andreconstructing a 3D image of the VOI from the imaging data. 20. The method according to claim 16, wherein the X-ray source is mounted for rotation with the gantry and emits an X-ray cone beam across the examination region to an X-ray detector, generating a half field of view across the VOI and generating a complementary half field of view when the gantry is rotated 180°. 21. The method according to claim 16, further comprising adjusting the wedge-shaped attenuation filter as a function of VOI size, shape, and density information. 22. An apparatus for generating a 3D patient image, including:means for generating a cone-shaped X-ray beam which traverses half of a VOI, such that the beam traverses the other half of the VOI when rotated 180°;means for detecting the X-ray beam;means for adjustably attenuating of the X-ray beam including a filter comprising a first lateral portion having a first thickness exposed to the X-ray beam, a second lateral portion having a second thickness exposed to the X-ray beam wherein the first thickness is greater than the second thickness, and a middle portion extending from the first lateral portion to the second lateral portion and having a thickness exposed to the X-ray beam which continually decreases from the first thickness to the second thickness;means for monitoring size, shape, and density of the VOI presented to the X-ray beam during a 360° revolution of the X-ray generating means and means around the VOI; andmeans for selectively adjusting X-ray attenuation across an entire lateral extent of the X-ray beam between the first lateral portion and the second lateral portion of the filter by the attenuation means as the X-ray generation means and the detecting means rotate around the VOI.
	description	This application is a continuation application of U.S. patent application Ser. No. 13/794,604 filed Mar. 11, 2013, now U.S. Pat. No. 10,128,003, which claims the benefit of U.S. Provisional Application No. 61/747,064, filed Dec. 28, 2012, all of which are incorporated herein by reference in their entirety. The present patent application relates to fuel assemblies and methods related to same. Disclosed embodiments include fuel ducts, fuel assemblies, methods of making and using same. The foregoing is a summary and thus may contain simplifications, generalizations, inclusions, and/or omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. In addition to any illustrative aspects, embodiments, and features described herein, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. Other aspects, features, and advantages of the devices and/or processes and/or other subject matter described herein will become apparent in the teachings set forth. In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, the use of similar or the same symbols in different drawings typically indicates similar or identical items, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. One skilled in the art will recognize that the herein described components (e.g., operations), devices, objects, and the discussion accompanying them are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific exemplars set forth and the accompanying discussion are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components (e.g., operations), devices, and objects should not be taken as limiting. The present application uses formal outline headings for clarity of presentation. However, it is to be understood that the outline headings are for presentation purposes, and that different types of subject matter may be discussed throughout the application (e.g., device(s)/structure(s) may be described under process(es)/operations heading(s) and/or process(es)/operations may be discussed under structure(s)/process(es) headings; and/or descriptions of single topics may span two or more topic headings). Hence, the use of the formal outline headings is not intended to be in any way limiting. Overview By way of overview, provided in one embodiment is a fuel assembly, the fuel assembly comprising: a fuel duct, including: a first hollow structure having a first cross-sectional geometry, and a second hollow structure having a second cross-sectional geometry, the second hollow structure disposed exterior to the first hollow structure, and the second cross-sectional geometry being different from the first cross-sectional geometry. Provided in another embodiment is a fuel assembly, the fuel assembly comprising: a fuel duct, including: a first hollow structure having at least one dimension that is changeable under stress, and a second hollow structure disposed exterior to the first hollow structure, the first hollow structure and the second hollow structure defining a space therebetween; the second hollow structure being adapted to distribute therethrough at least a portion of the stress of the first hollow structure. Provided in another embodiment is a fuel assembly, the fuel assembly comprising: a fuel, a plurality of fuel elements, and a plurality of fuel ducts having the plurality of fuel elements disposed therein, at least one of the plurality of the fuel ducts including: a first hollow structure having a first cross-sectional geometry, and a second hollow structure having a second cross-sectional geometry, the second hollow structure disposed exterior to the first hollow structure, and the second cross-sectional geometry being different from the first cross-sectional geometry. Provided in another embodiment is a method of making a fuel assembly, the method comprising: forming a first hollow structure adapted to change at least one dimension thereof under stress and a second hollow structure adapted to distribute therethrough at least a portion of the stress of the first hollow structure; disposing the first hollow structure interior to the second hollow structure to form a fuel duct such that a space is defined between the first hollow structure and the second hollow structure. Provided in another embodiment is a method of making a fuel assembly, comprising: forming a first hollow structure having a first cross-sectional geometry; forming a second hollow structure having a second cross-sectional geometry that is different from the first cross-sectional geometry; and disposing the first hollow structure interior to the second hollow structure to form a fuel duct. Provided in another embodiment is a method of using a fuel assembly, comprising: generating heat with a plurality of fuel elements disposed within a first hollow structure, the first hollow structure being disposed within a second hollow structure; subjecting the first hollow structure to stress; and distributing the stress of the first hollow structure through the second hollow structure. Fuel Assembly FIG. 1a provides a partial illustration of a nuclear fuel assembly 10 in accordance with one embodiment. The fuel assembly may be a fissile nuclear fuel assembly or a fertile nuclear fuel assembly. The assembly may include fuel elements (or “fuel rods” or “fuel pins”) 11. FIG. 1b provides a partial illustration of a fuel element 11 in accordance with one embodiment. As shown in this embodiment, the fuel element 11 may include a cladding material 13, a fuel 14, and, in some instances, at least one gap 15. A fuel may be sealed within a cavity by the exterior cladding material 13. In some instances, the multiple fuel materials may be stacked axially as shown in FIG. 1b, but this need not be the case. For example, a fuel element 11 may contain only one fuel material. In one embodiment, gap(s) 15 may be present between the fuel material 11 and the cladding material 13, though gap(s) need not be present. In one embodiment, the gap 15 is filled with a pressurized atmosphere, such as a pressured helium atmosphere. A fuel may contain any fissionable material. A fissionable material may contain a metal and/or metal alloy. In one embodiment, the fuel may be a metal fuel. It can be appreciated that metal fuel may offer relatively high heavy metal loadings and excellent neutron economy, which is desirable for breed-and-burn process of a nuclear fission reactor. Depending on the application, fuel may include at least one element chosen from U, Th, Am, Np, and Pu. The term “element” as represented by a chemical symbol herein may refer to one that is found in the Periodic Table—this is not to be confused with the “element” of a “fuel element.” In one embodiment, the fuel may include at least about 90 wt % U—e.g., at least 95 wt %, 98 wt %, 99 wt %, 99.5 wt %, 99.9 wt %, 99.99 wt %, or higher of U. The fuel may further include a refractory material, which may include at least one element chosen from Nb, Mo, Ta, W, Re, Zr, V, Ti, Cr, Ru, Rh, Os, Ir, and Hf. In one embodiment, the fuel may include additional burnable poisons, such as boron, gadolinium, or indium. In one embodiment, the interior of the first hollow structure of the fuel duct may include a plurality of fuel elements. In one embodiment, the metal fuel may be alloyed with about 3 wt % to about 10 wt % zirconium to dimensionally stabilize the alloy during irradiation and to inhibit low-temperature eutectic and corrosion damage of the cladding. A sodium thermal bond fills the gap that exists between the alloy fuel and the inner wall of the clad tube to allow for fuel swelling and to provide efficient heat transfer, which may keep the fuel temperatures low. In one embodiment, individual fuel elements 11 may have a thin wire 12 (FIG. 1a) from about 0.8 mm diameter to about 1.6 mm diameter helically wrapped around the circumference of the clad tubing to provide coolant space and mechanical separation of individual fuel elements 11. In one embodiment, the cladding 13 and/or wire wrap 12 may be fabricated from ferritic-martensitic steel because of its irradiation performance as indicated by a body of empirical data. Fuel Element A “fuel element”, such as element 11 shown in FIGS. 1a-1b, in a fuel assembly of a power generating reactor, may generally take the form of a cylindrical rod. The fuel element 11 may be a part of a power generating reactor, which is a part of a nuclear power plant. Depending on the application, the fuel element may have any suitable dimensions with respect to its length and diameter. The fuel element may include a cladding layer 13 and a fuel 14 disposed interior to the cladding layer 13. In the case of a nuclear reactor, the fuel may contain (or be) a nuclear fuel. In one embodiment, the nuclear fuel may be an annular nuclear fuel. The fuel element may additionally include a liner disposed between the nuclear fuel 14 and the cladding layer 13. The liner may contain multiple layers. The fuel may have any geometry. In one embodiment, the fuel has an annular geometry. In such an embodiment, a fuel in an annular form may allow a desirable level of fuel density to be achieved after a certain level of burn-up. Also, such an annular configuration may maintain compressive forces between the fuel and the cladding to promote thermal transport. The fuel may be tailored to have various properties, depending on the application. For example, the fuel may have any level of density. In one embodiment, it is desirable to have a high density of fuel, such as one as close to theoretical density uranium (in the case of a fuel containing uranium) as possible. In another embodiment, having a high porosity (low density) may prevent formation of additional internal voids during irradiation, decreasing fuel pressure on structural material, such as cladding, during operation of the nuclear fuel. The cladding material for the cladding layer 13 may include any suitable material, depending on the application. In one embodiment, the cladding layer 13 may include at least one material chosen from a metal, a metal alloy, and a ceramic. In one embodiment, the cladding layer 13 may contain a refractory material, such as a refractory metal including at least one element chosen from Nb, Mo, Ta, W, Re, Zr, V, Ti, Cr, Ru, Rh, Os, Ir, Nd, and Hf. In another embodiment, the cladding material may be chosen from a ceramic material, such as silicon carbide or aluminum oxide (alumina). A metal alloy in cladding layer 13 may be, in one exemplary embodiment, steel. The steel may be chosen from an austenitic steel, a ferritic-martensitic steel, an oxide-dispersed steel, T91 steel, T92 steel, HT9 steel, 316 steel, and 304 steel. The steel may have any type of microstructure. For example, the steel may include at least one of a martensite phase, a ferrite phase, and an austenite phase. In one embodiment, substantially all of the steel has at least one phase chosen from a martensite phase, a ferrite phase, and an austenite phase. Depending on the application, the microstructure may be tailored to have a particular phase (or phases). The cladding layer 13 may include an iron-based composition as described below. At least some of the components of the fuel elements may be bonded. The bonding may be physical (e.g., mechanical) or chemical. In one embodiment, the nuclear fuel and the cladding are mechanically bonded. In one embodiment, the first layer and the second layer are mechanically bonded. Stress Distribution In one aspect, the various structural components of the fuel assembly described herein may work together to distribute stress. The stress may refer to bending stress, tensile stress, axial stress, compressive stress, hoop stress, or combinations thereof. The stress may arise from the interior of the fuel assembly, such as the pressure of the gas and/or coolant in the interior of the duct, which gas has a tendency to create a pressure pushing outward. Referring to FIGS. 2a-2b, a pressure differential between the interior 21 and exterior 22 of a fuel duct 20 may create a driving force that causes the wall of the fuel duct 20 to stretch—i.e., to be in tension. The pressure differential may drive both thermally induced creep and radiation induced creep (see FIG. 2a vs. FIG. 2b for non-creeping structure and creeping structure, respectively) in a pre-existing duct design. Bulk swelling of structural materials in region 23 in nuclear reactors may also occur. The swelling may be independent of coolant pressure and can lead to bending stresses within the assembly structure. A further component of internal stress can be due to swelling of the fuel element bundles, which may also exert force on the assembly walls. Referring to FIG. 3a, current assemblies, such as those used in liquid metal cooled fast reactors, use a single walled, hexagonal fuel duct 31 to house wire-wrapped fuel elements. One current method to limit distortion is to make thicker walled hex-ducts. However, this may increase the ratio of structural material to fuel within a reactor core, decreasing a reactor's neutron economy and increasing the cost and weight of the assembly. Ducts with 12-sides have also been considered in current designs, shown as fuel duct 32 in FIG. 3b. Twelve-sided ducts 32 have a decreased side length and increased side-to-side internal angle. Such a design decreases the bending stress in the duct and therefore decreases the distortion. However, configuration of these 12-sided assemblies into their most compact lattice configuration (dodeca-cell packing as opposed to hex-cell packing; see FIG. 3b) may leave interstitial spaces 301, which need to be filled with coolant or fuel. In the former case, the ratio of coolant to fuel increases. In the latter case, multiple assembly types are needed for the reactor, increasing costs and fuel management complexity. Thus, none of these current approaches is desirable. The fuel assemblies described herein overcome these challenges. Fuel Duct Configuration Another aspect of the embodiments described herein is related to a structural component of a fuel assembly or the assembly itself. For example, one embodiment is related to a fuel duct of or for a fuel assembly. Referring to FIG. 4, a fuel duct in accordance with one embodiment may include a first hollow structure 401 having a first cross-sectional geometry and a second hollow structure 402 having a second cross-sectional geometry. The second hollow structure 402 may be disposed exterior or interior to the first hollow structure—FIG. 4 illustrates the former scenario. In one embodiment, the second cross-sectional geometry is different from the first cross-sectional geometry. In another embodiment, the second cross-sectional geometry is at least substantially the same as the first cross-sectional geometry. “Substantially the same” geometry in one embodiment herein may refer to the same geometry but with very small variations, such as a (slightly) blunt edge (instead of a sharp edge) or a side including at least some curvature. In another embodiment, the second cross-sectional geometry is the same as the first cross-sectional geometry. The terms “first,” “second,” “third,” etc., herein merely denote separate entities, and the order of these entities may be changed. Thus, the association between the numbers and the entities are not limiting. In some embodiments, the hollow structure may be referred to as a “duct,” as that in a “multi-ducted” configuration. The term “geometry” herein may refer to the shape and/or size of a material. For example, the structure described herein may have a cross-sectional area having a shape including (or of) a polygon having a plurality of sides (or edges), a circle, or an irregular shape. A polygon may be a triangle, square, rectangle, pentagon, hexagon, heptagon, octagon, enneagon, decagon, hendecagon, dodecagon, tridecagon, tetradecagon, pentadecagon, or other geometries having more sides. A circular cross-sectional area herein may also refer to an elliptical cross-sectional area. Thus, depending on the cross-sectional area, the structure in a three-dimensional sense may be a cube (or more sides), cylinder, etc. In some embodiments, the interior (relative to the second structure) first hollow structure and the exterior (relative to the first structure) second hollow structure may each include a polygon as their respective cross-sectional geometries. In one embodiment, the first cross-sectional geometry may include a polygon having more sides than the second cross-sectional geometry. In another embodiment, first cross-sectional geometry may include a polygon having the same number of sides as the second cross-sectional geometry. In another embodiment, the first cross-sectional geometry may include a polygon having fewer sides than the second cross-sectional geometry. In the case wherein the first and the second hollow structures have polygonal cross-sectional areas, the areas may have any of the aforementioned polygonal geometries. In one embodiment, the first cross-sectional geometry may include a dodecagon. In one embodiment, the second cross-sectional geometry may include a hexagon. In one embodiment where the first cross-sectional geometry may include a polygon having more sides than the second cross-sectional geometry, the first cross-sectional geometry may include a dodecagon and the second cross-sectional geometry may include a hexagon. In an alternative embodiment, the first cross-sectional geometry may include an octagon and the second cross-sectional geometry may include a square. In another embodiment, the first cross-sectional geometry may include a circle and the second cross-sectional geometry may include an octagon. In an alternative embodiment, the first cross-sectional geometry may include a polygon having fewer sides than the second cross-sectional geometry—e.g., the first cross-sectional geometry includes a hexagon and the second cross-sectional geometry includes an octagon. The hollow structures of the fuel assembly may have the same thickness or different thicknesses. The thickness need not be limited to any particular value and may vary depending on the application. For example, the thickness of the first hollow structure and/or the second hollow structure may be between about 0.1 mm and about 20 mm—e.g., between about 0.2 mm and about 15 mm, between about 0.3 mm and about 10 mm, between about 0.5 mm and about 5 mm, between 1 mm and about 3 mm, etc. The thickness of the first and/or second hollow structures may be uniform along the circumference of their respective cross-sectional geometries, though it need not be. In one embodiment, the at least one of the first hollow structure and the second hollow structure has a wall thickness varying along at least a portion of the respective circumferences of the first and second cross-sectional geometries. In some embodiments, a change in the thickness along a side or multiple sides may result in a change of curvature. As a result, as described above, a polygon with varying thicknesses and/or curvature along its different sides may become not a hexagon but be still substantially the same as a polygon geometry. The change of thickness and/or curvature may be optimized for different purposes—e.g., dilation performance. The hollow structures of the fuel assembly may have the same chemical composition or different chemical compositions. In some embodiments, the first and/or second hollow structures may include at least one material chosen from a Zr-based alloy, a Fe-based alloy, a ceramic, a refractory metal, a refractory alloy, and a composite material. The ceramic may be a carbide (e.g., silicon carbide), nitride, oxynitride, etc. For example, the first and/or second hollow structures may include a Fe-based alloy, including steel. The steel may be chosen from at least one of ferritic steel, martensitic steel, ferritic martensitic steel, and non-ferritic steel. Other materials that are suitable in a radiation environment may be used. As shown in FIG. 4, an interior space 411 of the first hollow structure may be sealed from outside of the first hollow structure. In one embodiment, space 411 in the sealed inner first hollow structure may contain at least one coolant in the interior space. The coolant may be disposed in a space 412 defined between the first hollow structure and the second hollow structure. In one embodiment, the inner first hollow structure is sealed such that it is full of coolant or contains a fluid or material that is distinct from the coolant. The fluid may be one having desirable neutron properties—e.g., multiplying, absorbing, or effectively transparent to radiation. In one embodiment, the interior space 411 may be substantially empty, such that any neutronic effect may be minimized. In another embodiment, the interior space 411 of the first hollow structure is substantially free of coolant. The space 411 may also be used to house instruments for both testing within the reactor and observation of normal and non-normal operating conditions, as well as devices to control the reactor, or to provide desired reactivity feedback, as described above. Alternatively, the interior may be exposed to the outside of the first hollow structure. The interior space 411 of the first hollow structure may be empty or may include certain materials. For example, at least one coolant may be disposed in the interior of the first hollow structure. The coolant may be any suitable coolant, depending on the application. For example, the coolant may include sodium. The space 412 defined by the first hollow structure and the second hollow structure may be empty; alternatively, additional elements may be present in the space. The space 412 may be defined by an outer wall 413 of the first hollow structure and an inner wall 414 of the second hollow structure. For example, in the space 412 may be a coolant, which may be any of the aforedescribed coolants. Alternatively or additionally, in the space 412 there may be at least one structural member as aforedescribed. In another embodiment, in the space 412 there may be at least one instrument, which may be configured to test, observe and provide feedback regarding operation conditions (e.g., of the fuel assembly). The instrument may be the same as or different from that employed in the interior space of the hollow structure as described above. In one embodiment, in the fuel duct the first hollow structure may have at least one dimension that is changeable under stress. Depending on the geometry of the first hollow structure, the dimension may refer to width, length, diameter, etc. The change in dimension may refer to, for example, expansion thereof. In one embodiment, the second hollow structure is adapted to distribute therethrough at least a portion of the stress of the first hollow structure. The first hollow structure may be adapted to expand radially outwards under stress such that at least a portion of the first hollow structure physically contacts the second hollow structure. In some cases, expansion need not happen. For example, the first hollow structure may substantially maintain at least one of its dimensions (such as all of its dimensions) and geometry under stress. In one embodiment, the first hollow structure is adapted to change at least one dimension thereof under stress; and the second hollow structure is adapted to distribute at least some of the stress of the first hollow structure. In another embodiment, the first hollow structure does not change its dimension and/or geometry under stress, and yet the second hollow structure may distribute at least some of the stress. The second hollow structure may distribute at least some of the stress of the first structure with a minimal amount of change (such as no change) of its dimension and/or geometry. In one embodiment, the second hollow structure is configured to substantially maintain at least one of its dimensions (such as all dimensions) and geometry during distribution therethrough of the stress of the first hollow structure. When the first hollow structure is not subjected to any stress, particularly that arising from the pressure in the interior thereof, the first hollow structure need not be in physical contact with the second exterior hollow structure (as shown in FIG. 4), although it may be. In one embodiment, when under stress the first hollow structure may be adapted to expand outwards until at least a portion thereof is in physical contact with the second hollow structure to distribute the stress. The second hollow structure may be designed and/or configured to distribute the stress without having to change its dimension and/or geometry. In one embodiment, the stress may be (but need not be) uniformly distributed among the different sides of the second hollow structure. Structural Members Referring to FIG. 5, the interior 503 of the first hollow structure 501 may include structural member(s) 502. The interior of a first hollow structure space 503 may also be compartmentalized, such as compartmentalized axially. In one embodiment, the axial compartmentalization may be accomplished with a reflector below the fuel column, a void along the length of the fuel column, then coolant above the fluid column. The structural members 502 may be positioned in any way that suits the purpose of the application. For example, a structural member 502 may couple to a point of a first side of the inner first hollow structure to a point of a second side opposite to the first side, as shown in FIG. 5. The point may be any point on the side, such as a mid-point. In one embodiment, a structural member 502 may couple to one corner (instead of to a side) of the first hollow structure to another corner (not shown). The term “couple to” herein may refer to being in contact, such as physical contact (e.g., mechanical coupling). In some other embodiments, the contact may refer to other types of contacts, such as thermal contact, electrical contact, etc. For example, two items being coupled to each other in one embodiment may refer to these two items being connected to each other by physical contact either directly or indirectly (via a third item). These structural members 502 in the interior of the first hollow structure 501 may be (or act as) tensioning structural members. In one embodiment, the outward force due to coolant internal pressure may be at least partially balanced by tension within these internal structural members as shown in FIG. 5. As a result, this configuration may reduce the distortion of the outer hollow structure (or “duct”) by decreasing both normal and bending stresses. In one embodiment, as shown in FIG. 4, the first hollow structure 401 and the second hollow structure 402 may be spaced apart from each other by a space 412 and not in contact with each other at all. In other words, the first hollow structure 401 and the second hollow structure 402 define a space 412 therebetween in this embodiment. Alternatively, at least a portion of the first hollow structure may be coupled to a portion of the second hollow structure. For example, referring to FIG. 6a, the first hollow structure 601 and second hollow structure 602 may contain space 612 therebetween, while the two structures 601, 602 are in contact with one another. These structural members may be the same or different from the internal structural members in the interior of some first inner hollow structure as described above. FIG. 6b provides an illustration of a fuel duct having a plurality of structural members 603 in the space 612 between the inner hollow structure 601 and the outer hollow structure 602 in one embodiment. In this embodiment, the structural members each couples at a point on a side of (an outer wall of) the inner hollow structure to an (inner) corner of the outer hollow structure. The point may be a mid-point or may be anywhere on the side. The structural member may be placed perpendicularly to the side (as shown in FIG. 6b) but need not be. For example, the structural member may be placed at an angle. At least one instrument may be disposed in the interior of the first hollow structure. The instrument(s) may be configured to perform at least one function chosen from testing, observing, and providing feedback regarding operation conditions. The conditions may refer to the conditions of any portion of the fuel assembly, including the fuel duct or any portion thereof. The instrument may include a device, such as a sensor device. The instrument may alternatively include a reflector. In one embodiment, the instrument may include a reactivity feedback device, a control element, or both. For example, the instrument may include a control-rod device, a lithium expansion module (LEM), an absorption insertion module (AIM), gas expansion module (GEM), etc. The contact may be accomplished by the sides of the first and second hollow structures being in physical contact (FIG. 6a) and/or via separate structural components 603 (FIGS. 6b-6d). In the latter, the two hollow structures may be coupled to each other via their sides (FIGS. 6b-6c) or solely by connecting by at least one structural member (FIG. 6d). Structural members need not be present on all sides or corners of the hollow structures, though they may be. As shown in, for example, FIGS. 6c-6d, only some of the sides and corners are connected by structural members. The structural member may include (or be), for example, a strut. The structural members may be disposed in the space defined between the first hollow structure and the second hollow structure and physically coupling the first hollow structure and the second structure. Structural members are not always needed. For example, in one embodiment, structural members between the inner and outer hollow structures may be removed to remove substantially all tensile stresses on the outer hollow structure. In one embodiment, the outer hollow structure may be engineered to accommodate dimensional changes due to void swelling, so that the spaces between fuel assemblies are minimized. In some embodiments, the inner and outer hollow structures may share at least one common face (or side if viewed in one-dimension), as shown in FIGS. 6a-6c. The structural member may be made of, or include, any suitable materials. For example, the structural member may be chosen from at least one of a metal, metal alloy, ceramic, and polymer. The structural member may include the same composition as or different composition from the first and/or second hollow structure. Depending on the size of the space between the first and the second hollow structures, the structural members may be of various sizes. For example, the structural member may have a diameter that is smaller than, the same as, or greater than that of the thickness of the first and/or second hollow structure. Penetrations The first hollow structure and/or the second hollow structure may include penetrations to allow fluid (e.g., coolants) to flow to facilitate removal of heat to maintain thermal conditions. For example, in an example where the fuel assembly is compartmentalized axially, penetrations may allow a coolant to enter the space above the fuel column between the first and second hollow structures. Any of the boundaries of these compartments may be designed to have a change in properties in response to some external condition. For example, one can have fusible plugs that allow a voided space to become filled with coolant or other material if a certain temperature is exceeded. FIGS. 7a-7d illustrate different phenomena associated with having penetrations in the inner duct 710 and/or outer duct 720. FIG. 7a provides an illustration of the pressure profile in one embodiment. FIG. 7b illustrates the bypass of fueled region 702 by coolant through the ‘voided’ portion 701 of the duct; this may take place when additional static pressure is needed outside of the inner portion of the assembly to distribute stress. FIG. 7c illustrates bypass of the above-fueled region 703 by coolant through the voided portion of duct; the above-fueled portion may produce significantly less heat so that the coolant flow rate through the middle of the channel may be reduced. FIG. 7c illustrates bypass of fueled region by coolant through the voided portion of duct with flow back into region above the fuel. FIG. 7d illustrates that coolant flow may be bypassed around the fueled region by letting some fluid escape from the assembly completely. A load pad 730 is also shown in FIG. 7d. This can be done to increase static pressure around the entirety of the ducts (in a case where there are multiple fuel assemblies). Flow exiting the assembly will have to squeeze between neighboring ducts which increases pressure, as shown in FIG. 7d. Power Generation As described above, the fuel assemblies described herein may be a part of a power or energy generator, which may be a part of a power generating plant. The fuel assembly may be a nuclear fuel assembly. In one embodiment, the fuel assembly may include a fuel, a plurality of fuel elements, and a plurality of fuel ducts, such as those described above. The fuel ducts may include the plurality of fuel elements disposed therein. At least some of the fuel assemblies described herein may include interstitial spaces among the plurality of the fuel ducts. The interstitial spaces may be defined as the space between the plurality of the fuel ducts. At least one of a coolant, inert gas, fuel material, and a monitoring device can be disposed in at least some of these interstitial spaces. The interstitial spaces may be empty or may include certain materials. For example, in the interstitial spaces may be at least one of a coolant, inert gas, and fuel material. The coolant and/or fuel material may be any of those described above. An inert gas may be any of those known in the art—e.g., nitrogen, a noble gas (e.g., argon, helium, etc). In some embodiments, the interstitial spaces may include an instrument, such as any of those described above that may be present in the interior of the first hollow structure or the space between the first and second hollow structure. In one embodiment, the instrument is a monitoring device monitoring the operation conditions of the fuel assembly. The fuel assembly described herein may be adapted to produce a peak areal power density of at least about 50 MW/m2—e.g., at least about 60 MW/m2, about 70 MW/m2, about 80 MW/m2, about 90 MW/m2, about 100 MW/m2, or higher. In some embodiments, the fuel assembly may be subjected to radiation damage at a level of at least about 120 displacements per atom (“DPA”)—e.g., at least about 150 DPA, about 160 DPA, about 180 DPA, about 200 DPA, or higher. Method of Making or Using Fuel Assembly In another aspect, a method of making an article of a fuel assembly is provided. The fuel assembly may be any of the aforedescribed fuel assemblies, including fuel ducts, fuel assemblies, and the like. FIG. 8a provides a flow chart of a process of making a fuel duct of the fuel assembly in one illustrative embodiment. The method may include forming a first hollow structure (step 801), which may be adapted to change at least one dimension thereof under stress, and forming a second hollow structure (step 802), which may be adapted to distribute therethrough at least a portion of the stress of the first hollow structure; and disposing the first hollow structure interior to the second hollow structure to form a fuel duct (step 803) such that a space is defined between the first hollow structure and the second hollow structure. Referring to FIG. 8b, the process may further comprise coupling the first hollow structure to the second hollow structure, such as with at least one structural member (step 804). Referring to FIG. 8c, the process may further comprise forming the first and/or second hollow structure by forming metal sheets into a polygonal shape an closing the polygonal shape (step 805). Referring to FIG. 8d, the process of forming may further comprise at least one process chosen from extruding and pilgering (step 806). In some embodiments, at least one of the first and second hollow structures may already be pre-formed and thus only needs to be provided to undergo a disposing process, which may also include assembling different hollow structures. FIG. 9a provides a flow chart of an alternative process of making a fuel duct of the fuel assembly in one illustrative embodiment. The method may include forming a first hollow structure (step 901), which may be adapted to change at least one dimension thereof under stress, and forming a second hollow structure (step 902), which may be adapted to distribute therethrough at least a portion of the stress of the first hollow structure; and disposing the first hollow structure interior to the second hollow structure to form a fuel duct (step 903) such that a space is defined between the first hollow structure and the second hollow structure. Referring to FIG. 9b, the process may further comprise joining a portion of the first hollow structure to the second hollow structure, such as with at least one structural member (step 904). Referring to FIG. 9c, the process may further comprise compartmentalizing axially an interior of the first hollow structure (step 905), as will be described further below. Referring to FIG. 9d, the process may further comprise forming the first and/or second hollow structure by extruding and/or pilgering (step 906). Alternatively (or additionally), referring to FIG. 9e, the process may further comprise forming the first and/or second hollow structure by forming metal sheets into a polygonal shape and closing the polygonal shape (step 907). The process of forming may involve any techniques available to form structural materials, including hollow structural materials. For example, the process of forming may include a process chosen from at least one of extruding and pilgering. Pilgering may refer to a metal-working process for reducing at least one dimension of a metal-containing tubular structure. In some embodiments, the process of forming may include forming metal sheets into a polygonal (tubular) shape—the term “tube” is employed here merely to describe a three-dimensional structure, and not necessarily a circular cylinder. The process may further comprise at least one of closing the polygonal tube by welding a seam, riveting, forming a seam and tack welding, forming a seam and isostatically compressing the seam and diffusion bonding. The process of forming may further include providing at least one structural member coupling a portion of the first hollow structure to a portion of the second hollow structure (step 804). The structural member may be any of those described above. In some embodiments, the process of forming may further comprise joining a first portion of the first hollow structure and a second portion of the second hollow structure. The joining may be carried out with at least one structural member. In one embodiment, the joining process need not involve welding the at least one structural member axially with respect to the first portion and the second portion. For example, the assembly may be fitted with a keeper type device or a guide. In one embodiment, the inner hollow structure may be sled into the outer hollow structure. The fuel assemblies described herein may be used to generate power, such as in a nuclear reactor core in a nuclear plant. The power may refer to electrical power, thermal power, radiation power, etc. FIG. 10(a) provides a flow chart describing the process involved in a method of using the fuel assemblies described herein in one illustrative embodiment. In one aspect, the method of using a fuel assembly described herein may include generating energy (e.g., heat) with a plurality of fuel elements disposed within a first hollow structure (step 1001), the first hollow structure being disposed within a second hollow structure; subjecting the first hollow structure to stress (step 1002); and distributing the stress of the first hollow structure through the second hollow structure (step 1003). Referring to FIG. 10(b), the method may further comprise allowing a portion of the first hollow structure to contact physically a portion of the second hollow structure (step 1004). The fuel assemblies may be any of those aforedescribed. For example, the second hollow structure may be configured to substantially maintain at least one of its dimension and geometry during distribution therethrough of the stress of the first hollow structure. In one embodiment, the second hollow structure may be configured to change at least one of its dimension and geometry during distribution therethrough of the stress of the first hollow structure. In one embodiment, the plurality of fuel elements may include fuel material that includes at least one of uranium and plutonium. All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in any Application Data Sheet, are incorporated herein by reference in their entirety, to the extent not inconsistent herewith. In the event that one or more of the incorporated literature and similar materials differs from or contradicts this application, including but not limited to defined terms, term usage, described techniques, or the like, this application controls. With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations are not expressly set forth herein for sake of clarity. The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled,” to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable,” to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components, and/or wirelessly interactable, and/or wirelessly interacting components, and/or logically interacting, and/or logically interactable components. In some instances, one or more components may be referred to herein as “configured to,” “configured by,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that such terms (e.g. “configured to”) can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise. While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of the subject matter described herein. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.” With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flows are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise. Those skilled in the art will appreciate that the foregoing specific exemplary processes and/or devices and/or technologies are representative of more general processes and/or devices and/or technologies taught elsewhere herein, such as in the claims filed herewith and/or elsewhere in the present application. While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims. Any portion of the processes described herein may be automated. The automation may be accomplished by involving at least one computer. The automation may be executed by program that is stored in at least one non-transitory computer readable medium. The medium may be, for example, a CD, DVD, USB, hard drive, etc. The selection of the hollow structures, including the assembly, may also be optimized by using the computer and/or a software program. The above-described embodiments of the invention can be implemented in any of numerous ways. For example, some embodiments may be implemented using hardware, software or a combination thereof. When any aspect of an embodiment is implemented at least in part in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. Also, the technology described herein may be embodied as a method, of which at least one example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in any order different from that illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments. All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “including” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc. As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law. As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc. Any ranges cited herein are inclusive. The terms “substantially” and “about” used throughout this Specification are used to describe and account for small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. In the claims, as well as in the specification above, all transitional phrases such as “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03. The claims should not be read as limited to the described order or elements unless stated to that effect. It should be understood that various changes in form and detail may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. All embodiments that come within the spirit and scope of the following claims and equivalents thereto are claimed.
043495079	claims	1. A drive for an absorber rod of a nuclear reactor comprising: a drive chamber mounted within the pressure vessel of a nuclear power plant, a drive piston mounted within said drive chamber for movement along its longitudinal axis, an absorber rod fixedly attached at one end to said drive piston and extending outside said drive chamber to a terminating surface at its other end, an equalizing surface fixedly attached to said drive piston, transverse to said longitudinal axis and facing the opposite direction of said terminating surface, means for controlled movement of said drive piston within said drive chamber independent of the medium contained within the pressure vessel, wherein both said absorber rod terminating surface and said equalizing surface are exposed to the medium contained within the pressure vessel. a drive chamber mounted within the pressure vessel of a nuclear power plant, a drive piston mounted within said drive chamber for movement along its longitudinal axis, a hollow absorber rod fixedly attached at one end to said drive piston and extending outside said drive chamber to a terminating surface at its other end, an equalizing surface fixedly attached to said drive piston, transverse to said longitudinal axis and facing the opposite direction of said terminating surface, means for controlled movement of said drive piston within said drive chamber independent of the medium contained within the pressure vessel, means for cooling said absorber rod with a cooling medium flowing within said hollow absorber rod, wherein said absorber rod terminating surface is exposed to the medium contained within the pressure vessel and said equalizing surface is exposed to said cooling medium. equalizing the inner driving forces contained within the reactor vessel acting on said piston drive in the axial direction, and applying force independent of said equalizing forces to said drive piston while maintaining the equalized inner drive forces constant. 2. The drive of claim 1 wherein the means for controlled movement of said drive piston is a fluid medium flowing through a first conduit into said drive chamber to effect movement of said drive piston in one direction and flowing through a second conduit into said drive chamber to effect movement of said drive in the opposite direction. 3. The drive of claim 2 wherein said drive chamber is sealed from the medium contained within the pressure vessel by sealing gaskets and means for isolation of medium leaking past said sealing gaskets. 4. The drive of claim 3 wherein said equalizing surface is attached to a member extending in the opposite direction of said absorber rod. 5. The drive of claim 4 wherein said exposed surface area of said equalizing surface equals said exposed surface area of said terminating surface. 6. A drive for an absorber rod of a nuclear reactor comprising: 7. The drive of claim 6 wherein the means for controlled movement of said drive piston is a fluid medium flowing through a first conduit into said drive chamber to effect movement of said drive piston in one direction and flowing through a second conduit into said drive chamber to effect movement of said drive in the opposite direction. 8. The drive of claim 7 wherein said equalizing surface is the inner surface of said hollow absorber rod. 9. A method for controlling a piston drive for an absorber rod of a high temperature nuclear reactor comprising: 10. The method fo claim 9 wherein said nuclear reactor is a gas cooled high temperature reactor and said equalizing step comprises directing the medium of a pressure vessel against an equalizing surface of an absorber unit and a terminating surface of an absorber rod said equalizing surface and terminating surface facing opposite directions. 11. The method of claim 9 or 10 wherein said nuclear reactor is a gas cooled high temperature reactor and said medium is the cooling medium. 12. The method of claim 11 wherein said step of applying an independent force to said piston drive comprises flowing a fluid medium through a conduit into a drive chamber housing said drive piston and sealed from said medium of the pressure vessel.
048184683	abstract	A method is provided for preparing medicinally acceptable .sup.123 I by bombarding an XI (X is alkali metal or I) target in the liquid phase with a proton beam of a predetermined amperage and energy, while continuously passing a helium stream, optionally having a small amount of xenon, through the target area. The radioactive xenon collected by the helium stream is trapped in a cold trap, purified and then isolated in a deacy vessel, where the xenon decays to .sup.123 I. An iodine scavenger is provided for the helium effluent from the target, to remove any iodine from the helium stream, which would decrease the purity of the desired isotope.
	claims	1. A decreasing composition, comprising a base, a saturated or unsaturated polyethoxylated fatty alcohol, a copolymer of ethylene oxide and propylene oxide, and water, in which the base has a concentration in OHxe2x80x94 ions in a range from 0.1 to 1.5 mol.l xe2x88x921 , in which the saturated or unsaturated polyethoxylated fatty alcohol, is at a concentration in a range from about 0.01 to about 1.5% by weight, and in which the copolymer of ethylene oxide and propylene oxide has a concentration in a range from about 0.025 to about 1.5% by weight. 2. A composition according to claim 1 , in which the fatty alcohol is selected from the group consisting of lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, arachidyl alcohol, myristyl alcohol, oleic alcohol and linoleic alcohol. claim 1 3. A composition according to claim 1 , in which the polyethoxylated fatty alcohol is a compound of the following formula (I): claim 1 Rxe2x80x94(xe2x80x94Oxe2x80x94CH 2 xe2x80x94CH 2 ) n xe2x80x94OHxe2x80x83xe2x80x83(1) in which R is a saturated or unsaturated alkyl group comprising from 10 to 24 atoms of carbon, and in which n represents the monomeric unit number of ethylene oxide, wherein n is fron 10 to 30. 4. A composition according to claim 1 , in which the polyethoxylated fatty alcohol is a ether of oleic alcohol and an ethylene polyoxide with 20 monomeric units of ethylene oxide, according to the following formula (II): claim 1 5. A composition according to claim 1 , in which the copolymer of ethylene oxide and propylene oxide is a block copolymer. claim 1 6. A composition according to claim 1 in which the copolymer of ethylene oxide and propylene oxide is a block copolymer of the following formula (III): claim 1 7. A composition according to claim 1 further comprising a foam inhibitor agent. claim 1 8. A degreasing liquid comprising a composition according to claim 1 comprising about 0.05 to about 0.4% by weight of polethoxylated fatty alcohol, about 0.025 to about 0.6% by weight of copolymer of ethylene oxide and propylene oxide, about 0.5 to about 1 mol.l xe2x88x921 in OH xe2x88x92 ions, and further comprising a foam inhibitor agent. claim 1 9. A degreasing liquid according to claim 8 , in which the foam inhibitor agent is a branched or unbranched alkyl phosphate, comprising 4 to 12 atoms of carbon. claim 8 10. A degreasing liquid according to claim 8 in which the inhibitor agent is a branched alkyl phosphate, comprising from 6 to 12 carbon atoms, at a concentration of 0.1 to 0.4% by weight. claim 8 11. A degreasing foam comprising a gaseous phase and a degreasing composition according to claim 1 which further comprises a foam destabilizing agent. claim 1 12. A degreasing foam comprising a gaseous phase, and a degreasing composition according to claim 1 , in which said composition comprises a saturated or unsaturated polyethoxylated fatty alcohol, at a concentration in a range from about 0.4 to about 1.5% by weight, a copolymer of ethylene oxide and propylene oxide at a concentration in a range from about 0.4 to about 1.5% by weight, said composition which further comprises a foam destabilizing agent. claim 1 13. A degreasing foam according to claim 11 , in which the foam destabilizing agent is a branched or unbranched alkyl phosphate, comprising from 4 to 12 atoms of carbon. claim 11 14. A degreasing foam according to claim 11 in which said foam destabilizing agent is a branched alkyl phosphate comprising 6 to 10 atoms of carbon, which is at a concentration of 0.2 to 1.1% by weight in the composition, wherein the weight ratio in the composition of the concentration of the saturated or unsaturated polyethoxylated fatty alcohol to the concentration of the copolymer of ethylene oxide and propylene oxide is about 1.5. claim 11 15. A degressing gel comprising a degreasing composition according to claim 1 and further comprising a viscosity agent. claim 1 16. A degreasing gel comprising a degreasing composition according to claim 1 , in which the saturated or unsaturated polyethoxylated fatty alcohol has a concentration in a range from about 0.05 to about 1% by weight, the copolymer of ethylene oxide and propylene oxide has a concentration in a range from about 0.025% to about 0.4% by weight, and further comprising a viscosity agent. claim 1 17. A degreasing gel according to claim 15 in which the viscosity agent is selected from the group consisting of xanthan gum, an aluminum oxide and silica gel. claim 15 18. A process of degreasing a surface, said process comprising putting the surface to be degreased into contact with a composition according to claim 1 . claim 1 19. A process of degreasing a surface, said process comprising putting into contact the surface to be degreased with a liquid according to claim 8 . claim 8 20. A process of degreasing a surface, said process comprising putting into contact the surface to be degreased with a foam according to claim 11 . claim 11 21. A process of degreasing a surface, said process comprising putting into contact the surface to be degreased with a gel according to claim 15 . claim 15 22. A process of radiochemical decontamination of a surface comprising the steps of degreasing of the surface by a process according to claim 18 and subsequent radioactive decontamination of said degreased surface. claim 18 23. A process according to claim 22 , in which the radioactive decontamination is decontamination by chemical erosion of sail surface. claim 22 24. A process according to claim 23 , in which the chemical erosion of said surface is selected from the group consisting of cerium erosive treatment, an HF erosive treatment, or a ruthenium specific treatment. claim 23
	claims	1. A method of storing nuclear fuel outside of a nuclear reactor core, the method comprising at least one of:submerging at least a portion of a nuclear fuel rod in a storage pool comprising an aqueous solution comprising polyhedral boron hydride anions dissolved in the aqueous solution,wherein the aqueous solution with the anions dissolved therein is free of organic polymers; oradding a salt comprising a polyhedral boron hydride anion to a storage pool comprising water and at least a portion of a nuclear fuel rod submerged therein, wherein adding the salt provides an aqueous solution comprising polyhedral boron hydride anions dissolved in the aqueous solution,wherein the aqueous solution with the anions dissolved therein is free of organic polymers. 2. The method of claim 1, wherein the nuclear fuel rod or the portion thereof is a spent fuel rod or a portion thereof or a used fuel rod or a portion thereof. 3. The method of claim 1, wherein the nuclear fuel rod or the portion thereof is a fresh fuel rod or a portion thereof. 4. The method of claim 1, wherein the nuclear fuel rod or portion thereof is a used fuel rod, the method further comprising receiving the used fuel rod from the nuclear reactor core into the storage pool comprising the aqueous solution comprising the polyhedral boron hydride anions dissolved in the aqueous solution. 5. The method of claim 1, wherein the storage pool has at least 20 feet (6.1 meters) of the aqueous solution over the nuclear fuel rod or portion thereof. 6. The method of claim 1, wherein the storage pool further comprises a rack on which the nuclear fuel rod or portion thereof is placed. 7. The method of claim 1, wherein the polyhedral boron hydride anions are enriched in 10B. 8. The method of claim 1, wherein the polyhedral boron hydride anions carborane anions comprise at least one of B10H102−, or B12H122−. 9. The method of claim 1, wherein the polyhedral boron hydride anions comprise at least one of B10H102− or B12H122−. 10. The method of claim 1, further comprising dissolving a salt selected from the group consisting of Li2B10H10, Na2B10H10, K2B10H10, (NH4)2B10H10, LiB11H14, NaB11H14, KB11H14, (NH4)B11H14, Li2B12H12, Na2B12H12, K2B12H12, (NH4)2B12H12, and combinations thereof in water to provide the aqueous solution. 11. The method of claim 1, further comprising dissolving a Group I salt or ammonium salt comprising the polyhedral boron hydride anions in water to provide the aqueous solution. 12. The method of claim 11, wherein the Group I salt or ammonium salt has at least 25 percent by weight boron. 13. The method of claim 1, further comprising dissolving a salt having a water solubility of at least 15 grams per 100 grams of solution at 20° C. in water to provide the aqueous solution comprising the polyhedral boron hydride anions dissolved in the aqueous solution. 14. A storage pool comprising:an aqueous solution comprising polyhedral boron hydride anions dissolved in the aqueous solution,wherein the aqueous solution with the anions dissolved therein is free of organic polymers; andat least a portion of a nuclear fuel rod submerged in the aqueous solution, wherein the nuclear fuel rod is outside of a nuclear reactor core. 15. The storage pool of claim 14, wherein the polyhedral boron hydride anions comprise at least one of B10H102−, B11H14−, or B12H122−. 16. The storage pool of claim 14, wherein the polyhedral boron hydride anions comprise at least one of B10H102− or B12H122−. 17. The storage pool of claim 14, wherein the aqueous solution comprises a salt selected from the group consisting of Li2B10H10, Na2B10H10, K2B10H10, (NH4)2B10H10, LiB11H14, NaB11H14, KB11H14, (NH4)B11H14, Li2B12H12, Na2B12H12, K2B12H12, (NH4)2B12H12, and combinations thereof dissolved in the aqueous solution. 18. The storage pool of claim 14, wherein the aqueous solution comprises a Group I salt or ammonium salt comprising the polyhedral boron hydride anions dissolved in the aqueous solution. 19. The storage pool of claim 18, wherein the Group I salt or ammonium salt has at least 25 percent by weight boron. 20. A method of storing nuclear fuel outside of a nuclear reactor core, the method comprising at least one of:submerging at least a portion of a nuclear fuel rod in a storage pool comprising an aqueous solution comprising polyhedral boron hydride anions dissolved in the aqueous solution,wherein the aqueous solution with the anions dissolved therein is free of organic polymers; oradding a salt comprising a polyhedral boron hydride anion to a storage pool comprising water and at least a portion of a nuclear fuel rod submerged therein,wherein adding the salt provides an aqueous solution comprising polyhedral boron hydride anions dissolved in the aqueous solution,wherein the aqueous solution with the anions dissolved therein is free of organic polymers,wherein the polyhedral boron hydride anions have a cage structure.
	summary
	summary
048333298	abstract	A system for eluting a daughter radioisotope from a parent radioisotope and containerizing the resultant eluate in an evacuated container having a rubber stopper, providing for delivery of eluant from a reservoir through a tube to a generator containing the parent radioisotope, for venting of the reservoir to atmosphere via a tube, and for delivery of eluate from the generator via a tube to a tubular needle pierced through the stopper, with a cam-controlled hinged pinch plate for pinching the tubes closed.
	summary
	abstract	A stable startup system includes a reactor vessel containing coolant, a reactor core submerged in the coolant, and a heat exchanger configured to remove heat from the coolant. The stable startup system further includes one or more heaters configured to add heat to the coolant during a startup operation and prior to the reactor core going critical.
055436153	abstract	A beam charge exchanging apparatus causes the charges of charged particles in a fast particle beam to be exchanged with charges of a gas or other fluid. The apparatus includes; a gas/fluid container disposed in a vacuum and having holes which allow the fast particle beam to pass through the container, a source of gas or other fluid, and a nozzle for introducing the gas into the container. The source and the nozzle are designed to introduce a high speed gas/fluid into the container so that the fast particle beam will collide with the high speed gas/fluid in the container and the charges thereof will be exchanged such that the fast particle beam is converted into a neutral particle beam. The apparatus may further include elements for detecting the quantity of neutral particles resulting from the charge exchange by measuring the quantity of generated ionized gas as an electric current.
	abstract	A sample fabricating method of irradiating a sample with a focused ion beam at an incident angle less than 90 degrees with respect to the surface of the sample, eliminating the peripheral area of a micro sample as a target, turning a specimen stage around a line segment perpendicular to the sample surface as a turn axis, irradiating the sample with the focused ion beam while the incident angle on the sample surface is fixed, and separating the micro sample or preparing the micro sample to be separated. A sample fabricating apparatus for forming a sample section in a sample held on a specimen stage by scanning and deflecting an ion beam, wherein an angle between an optical axis of the ion beam and the surface of the specimen stage is fixed and formation of a sample section is controlled by turning the specimen stage.
	summary
050323474	summary	FIELD OF THE INVENTION The invention relates to a device for straightening the guide fins of the spacer grids of a fuel assembly of a nuclear reactor. BACKGROUND OF THE INVENTION The fuel assemblies of nuclear reactors, such as pressurized-water nuclear reactors, comprise a framework in which fuel rods of great length are disposed in order to form a bundle The framework comprises spacer grids which are spaced relative to one another along the length of the assembly and connected together by guide tubes. Each of the spacer grids comprises an assembly of cells each intended to receive a fuel rod and disposed in a regular network, generally a squared mesh. The network forming the grid is surrounded by a frame whose transverse section corresponds to the section of the assembly and which consists of small plates assembled together, for example in the form of a contour of squared form. The small plates forming the frame of the spacer grid are cut along their longitudinal edges to form fins which project relative to the upper lower faces of the spacer grid. The fins are folded towards the inside of the grid along the edge of the corresponding small plate and so as to form a perfectly defined angle with the latter. The fins of the spacer grids are intended, on the one hand, to facilitate the guiding of the fuel assembly when it is positioned in the core of the reactor or in a storage cell and, on the other hand, to ensure mixing of the primary coolant circulating in contact with the fuel assembly during operation of the reactor. The guide fins of the spacer grids of the fuel assemblies are inclined inwards so as to prevent the grid of the assembly from hooking onto the structure of the internal equipment of the tank of the reactor or onto an adjacent fuel assembly during refuelling or discharging of the core of the reactor. The fins of the spacer grids of the fuel assemblies may be deformed or folded under the effect of impacts which occur during their handling or produced by foreign bodies entrained by the coolant and circulating at high speed during operation of the reactor. After a period of operation of the order of one year, the fuel assemblies contained in the tank of the reactor and forming the core may be examined, before being refuelled into the core, in order to determine whether any of them have been damaged. Generally, only one-third of the assemblies of the core are renewed, but all the fuel assemblies are discharged in order to permit checking, for example inside the tank of the reactor. The fuel assemblies are placed under water in a pool, such as a storage pool, in order to be examined before their possible refuelling into the core. After an extended operating time, the guide fins of the spacer grids of some assemblies may be deformed, for the reasons given above. In order to be able to reuse the fuel assemblies whose spacer grids may have deformed fins, it has been proposed to compensate for the fins which are deformed or folded at an angle different from their defined angle of inclination by completely folding the fins which are deformed or in an incorrect position in order to press them against the wall of the corresponding grid. However, when this is done, the fins can no longer fulfil their role in respect of guiding the assembly nor in respect of mixing the primary cooling fluid circulating in contact with the assembly. Moreover, this operation of completely folding the fins runs the risk of leading to their breakage along the folding line before reaching the final position of the fin in contact against the small plate. This risk is greater when the metal of the small plate has been rendered less ductile due to irradiation. Moreover, the devices proposed for performing these operations of completely refolding the fins are ill-adapted to implementation under a depth of water which is greater than the minimum biological protection, which corresponds to a depth of 3 meters. SUMMARY OF THE INVENTION The invention relates a device for straightening the guide fins of the spacer grids of a fuel assembly of a nuclear reactor intended for the transverse retention of the fuel rods and comprising an outer frame whose transverse section corresponds to the section of the assembly consisting of small metal plates comprising, on at least one of their sides corresponding to one of the edges of the frame, an assembly of fins having an inclination which is perfectly defined relative to the corresponding small plate. The operation for straightening the fins whose inclination has been modified by folding during operation or handling of the fuel assembly is effected remotely and under a certain depth of water in a pool by the device comprising a rod of great length on which is mounted a means for support and displacement of a work tool at the level of the assembly and which is movable in the axial direction of the rod and in two directions perpendicular to the axial direction of the rod, this device making it possible to reestablish the inclination of the fins very precisely regardless of their position in the deformed state, with operations being commanded and controlled remotely. To this end, the work tool comprises: a guide means fixed rigidly on the tool support and having a slide which has a direction perpendicular to the shaft of the rod, PA0 a sliding block mounted so as to move on the slide of the guide means, PA0 a bearing stop fixed rigidly to one of the ends of the guide means in the vicinity of a corresponding end of the slide, PA0 at least one means for folding at least one fin integrally attached to one end of the sliding block which is distant from the shaft of the rod and located outside the slide of the guide means, in the vicinity of the bearing stop, PA0 a remotely controlled means for displacing the sliding block in the guide means, and PA0 at least one video camera carried by the support in order to provide an image of the zone in which straightening is being performed.
	summary
	abstract	A transponder card for a nuclear reactor control rod drive control system is provided. The control system includes a control processor and a plurality of electrical devices operationally coupled to the control processor. The transponder card is configured to receive commands from the control processor, energize an appropriate electrical device when commanded, detect a failure in control circuitry of the transponder card, send a failure alarm, and remove power from an electrical device during a control circuitry failure event when there is no command to energize the electrical device.
054835720	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to an x-ray apparatus comprising a carrier supporting an x-ray source for producing an x-ray beam, an x-ray detector facing the x-ray source and an adjustable absorption filter which is arranged between the x-ray source and the x-ray detector, the carrier being moveable to direct the x-ray beam path. 2. Description of the Related Art An x-ray apparatus of said kind is known from the European patent application EP 0 496 438 which corresponds to U.S. Pat. No. 5,287,396. An x-ray apparatus as described in the cited European patent application is provided with absorption filters having the form of moveable wedge filters. To prevent areas in an x-ray image from being overexposed, wedge filters are positioned so that very low x-ray absorption areas adjacent to strong x-ray absorption areas are blocked out to some extent. Wedge filters are positioned in the known x-ray examination apparatus on the basis of contour recognition during the formation of the x-ray image. Consequently, complicated image processing means are required. SUMMARY OF THE INVENTION It is an object of the invention to provide an x-ray examination apparatus for producing an x-ray image in which overexposed areas are reduced. It is also an object of the invention to reduce a dose of x-radiation required for producing the x-ray image. To achieve this, an x-ray examination apparatus according to the invention is characterized in that the x-ray examination apparatus is provided with filter-control means for accepting a posture of the carrier and furnishing a position of the absorption filter so as to control the adjustment of the absorption filter. When a shadow-image is made of a part of a patient's body to be examined by means of x-irradiation, there are areas of the x-ray image in which overexposure is to be avoided in that these areas are blocked out by means of an absorption filter. The location of such areas with respect to a region of interest in the x-ray image is determined by the orientation of the x-ray beam path with respect to the patient. Since anatomical structures show a comparatively limited variation among various patients, the location of areas subjected to risk of overexposure is predominantly determined from the position of the carrier on which the x-ray source and the x-ray detector are mounted. Thus, absorption filters are adequately positioned by providing filter-control means that control the positioning of the moveable absorption filter on the basis of the posture of the carrier. In this manner, with respect to the patient and with respect to a patient support table, protracted irradiation of the patient is avoided when a person operating the x-ray examination apparatus adjusts the absorption filter. Thus, subjection of both patient on operating personnel to harmful x-radiation is reduced. A preferred embodiment of an x-ray examination apparatus in according to the invention is characterized in that the filter-control means comprises a memory device for storing pairs of position data, a pair consisting of a position data of the absorption filter and a posture of the carrier. The filter-control means is further adequately operated by providing a memory device in which positions of the carrier and corresponding position adjustment data of the absorption filter are stored. These data constitute one or several adjustment curves which represent the positioning of the absorption filter on the basis of the posture of the carrier. A further preferred embodiment of an x-ray examination apparatus according to the invention is characterized in that the filter-control means is arranged to furnish a translation of the absorption filter with respect to the x-ray beam path from said posture of the carrier. In particular, overexposure is avoided in an area in the x-ray image in that the absorption filter is moved into the x-ray beam to some extent by translating the absorption filter with respect to the x-ray beam path. In this manner part of the x-ray beam is attenuated to some extent. When the filter-control means is provided with a memory device, then the memory device will preferably contain an adjustment curve representing translation distances of the absorption filter corresponding to postures of the carrier. A further preferred embodiment of an x-ray examination apparatus according to the invention is characterized in that the absorption filter is rotatable and comprises an x-ray absorbing part and an x-ray transmitting part and that the filter-control means is arranged to furnish an orientation of the absorption filter with respect to an axis of rotation of the absorption filter. A sophisticated absorption filter comprises an x-ray absorbing part and an x-ray transmitting part which has the shape of a section of a substantially circular disk and such an absorption filter is slidable into or out of the x-ray beam path and is in addition rotatable about an axis of rotation making right angles to the plane of the disk section. By rotating of the absorption filter being within in or close to the x-ray beam path, portions of the x-ray beam having a comparatively more complicated form can be blocked out. In an x-ray examination apparatus in according to the invention, the absorption filter is controlled by the filter control means so as to adequately position the absorption filter and block out a relevant portion of the x-ray beam. When the filter-control means is provided with a memory device, this memory device will preferably contain an adjustment curve representing orientation angles of the absorption filter corresponding to postures of the carrier. A further preferred embodiment of an x-ray examination apparatus according to the invention is characterized in that the memory device is arranged to store a plurality of sets of said pairs of position data, each set corresponding to a class of objects to be examined. Although the anatomical structure of various patients may be comparatively similar, there is some variation between various groups of patients, such as e.g. corpulent or slender patients or adults or infants. When patients from either group are examined, an even more adequate adjustment of the absorption filter is achieved when various adjustment curves are provided in said memory device, each adjustment curve pertaining to one of said groups of patients. These and other aspects of the invention will become apparent from and will be elucidated with reference to the embodiments described hereinafter and with reference to the accompanying drawings.
06233302&	claims	1. A method of fueling a nuclear reactor comprising: loading a first group of fresh unburnt MOX fuel rod assemblies into a first set of predetermined positions in a core of the reactor, in accordance with a predetermined location schedule; loading a second group of MOX fuel rod assemblies which have been burned once, into a second set of predetermined positions which are selectively arranged in the core with respect to the first set of predetermined positions, in accordance with the predetermined location schedule; and loading a third group of MOX fuel rod assemblies which have been burned twice, into a third set of predetermined positions which are selectively arranged in the core with respect to the first and second set of predetermined positions, in accordance with the predetermined location schedule wherein upon completion of loading the core, the core consists essentially of said first, second and third groups, and burnable absorber rods containing urania-erbia. a first group of fresh MOX fuel rod assemblies which are unburnt and which are loaded into a first set of predetermined positions in the core, in accordance with a predetermined location schedule; a second group of MOX fuel rod assemblies which have been burned once, and which are loaded into a second set of predetermined positions which are selectively arranged in the core with respect to the first set of predetermined positions, in accordance with the predetermined location schedule; a third group of MOX fuel rod assemblies which have been burned twice, and which are loaded into a third set of predetermined positions which are selectively arranged in the core with respect to the first and second set of predetermined positions, in accordance with the predetermined location schedule and burnable absorber rods containing urania-erbia. 2. A method of fueling as set forth in claim 1, further comprising the step of selecting the first group of fuel rod assemblies so as to comprise one or more of a plurality of predetermined octantly symmetrical assembly designs which each contain different amounts of plutonium, and so that an equilibrium cycle for the core exhibits a predetermined relationship with a predetermined equilibrium cycle produced using urania fuel. 3. A method of fueling as set forth in claim 2, further comprising the step of distributing the amount of plutonium, which is contained in the fuel rods of each of the plurality of octantly symmetrical assembly designs, in accordance with a plurality of predetermined distribution schedules. 4. A nuclear reactor core consisting essentially of: 5. A nuclear reactor core as set forth in claim 4, wherein the first group of fuel rod assemblies comprise one or more of a plurality of predetermined octantly symmetrical assembly designs which each contain different amounts of plutonium, and are so configured that an equilibrium cycle for the core exhibits a predetermined relationship with a predetermined equilibrium cycle produced using urania fuel. 6. A nuclear reactor as set forth in claim 5, wherein the amount of plutonium which is contained in the fuel rods of each of the plurality of octantly symmetrical assembly designs, is distributed in accordance with a respective plurality of predetermined distribution schedules.
	summary
	abstract	A shielded X-ray radiation apparatus is provided comprising an X-ray source, an X-ray attenuation shield including an elongate cavity to house the X-ray source and incorporating a region to accommodate a sample, a neutron attenuation shield, and a gamma attenuation shield. The neutron attenuation shield is situated adjacent to and substantially surrounds the X-ray attenuation shield and the gamma attenuation shield is adjacent to and substantially surrounds the neutron attenuation shield. In some embodiments a removable sample insertion means is provided to insert samples into the elongate cavity and which is composed of adjacent blocks of material, each respective block having a thickness and a composition which substantially matches the thickness and a composition of one of the X-ray attenuation, neutron attenuation and gamma-ray attenuation shields.
050341847	abstract	A high speed air cylinder in which the longitudinal movement of the piston within the air cylinder tube is controlled by pressurizing the air cylinder tube on the accelerating side of the piston and releasing pressure at a controlled rate on the decelerating side of the piston. The invention also includes a method for determining the pressure required on both the accelerating and decelerating sides of the piston to move the piston with a given load through a predetermined distance at the desired velocity, bringing the piston to rest safely without piston bounce at the end of its complete stroke.
	abstract	Space charge effects in an ion implanter can be caused by the mutual repulsion of ions of a particular polarity in a beam of ions which tend to cause the beam to xe2x80x9cblow upxe2x80x9d and become uncontrollable. This occurs for example in the ion implanter along the path of the ion beam and in particular at regions of external electric field. Introducing into the ion beam a second polarity of ions space charge neutralises the ion beam.
051436540	abstract	A method of solidifying a radioactive waste of an atomic power plant, for example, begins with concentrating the liquid waste to powder or pellet form to reduce its volume. Prior to reducing its volume, an estimation is made of what the concentration will be once the liquid waste is converted into powdered or pelletized form. The powdered or pelletized waste is charged into a container, and a solidifying agent is poured over the contents to form a solidified body. The solidifying agent is prepared to have a desired coefficient of distribution that is determined in accordance with the estimated concentration of the reduced volume solidified waste so that the amount of leaching of the solidified body that is produced will be less than or equal to a predetermined value, such as the known value of leaching for a conventional cement-solidified waste that is not processed to reduce its volume before being solidified.
	summary
	description	1. Field of the Invention The present invention relates to a laser irradiation apparatus to crystallize the semiconductor film and the like or to activate them after ion implantation by using laser light. In addition to that, the laser irradiation apparatus according to the present invention includes a laser irradiation apparatus to irradiate the laser light on the semiconductor film which is polycrystalline or near-polycrystalline, and improve (promote) crystallinity of the semiconductor film. Furthermore, the present invention relates to a method of manufacturing a semiconductor device using the crystalline semiconductor film formed by the laser irradiation apparatus above. 2. Description of the Related Art In recent years, the technology to form TFT on a substrate makes great progress and application development to an active matrix type semiconductor device is advanced. Especially the TFT with the polycrystalline semiconductor film is superior in field-effect mobility to TFT with a conventional amorphous semiconductor film and thereby high-speed operation becomes possible. Therefore, it has been tried that pixel that was controlled by the driver circuit provided outside of the substrate so far is controlled by the driver circuit formed on the same substrate as the pixel. By the way, a substrate for the semiconductor device represented by the TFT is expected to be a glass substrate rather than a monocrystal silicon substrate in terms of its cost. However, a glass substrate is inferior in heat resistance and easy to change its shape when heated. Therefore, when forming the TFT with a polysilicon semiconductor film on a glass substrate, in order not to change the shape of the glass substrate because of heat, laser annealing is performed to crystallize the semiconductor film. The characteristic of laser annealing is that the processing time can be drastically shortened when compared with annealing method by radiation heating or conductive heating, and that a semiconductor substrate or a semiconductor film can be heated selectively and locally so that the substrate will be hardly damaged thermally. It is noted that the laser annealing method described here indicates the technology to recrystallize an amorphous layer or a layer damaged by the impurity doping formed on the semiconductor substrate or the semiconductor film, or the technology to crystallize an amorphous semiconductor film formed on the substrate. Moreover, the technology to planarize or modify the surface of the semiconductor substrate or the semiconductor film is also included. The lasers used for laser annealing are classified broadly into two types according to its oscillation system. In recent years, it has been known that in crystallization of the semiconductor film, a crystal grain formed in the semiconductor film is larger when using a continuous oscillation laser than when using a pulse oscillation laser. When the crystal grain formed in the semiconductor film is large, the number of the grain boundary included in the TFT channel region formed by using the semiconductor film decreases and thereby the mobility becomes high. As a result, such semiconductor film can be applied to a device with high-performance. For this reason, the continuous oscillation laser is beginning to attract attention. Moreover, when performing laser annealing on the semiconductor or the semiconductor film, the method to convert a laser beam emitted from the laser by an optical system so as to become an elliptical shaped or a line shaped beam and scan a beam spot (surface to be irradiated by the laser) to a surface to be irradiated is known. This method enables an effective irradiation of the laser light on the substrate so that mass-productivity can be enhanced and is superior in the industrial purpose. Therefore this method is employed preferably. (Reference: patent document 1 for example) Patent document 1: Japanese Patent Application laid-open Hei. 8-195357 In order to perform laser annealing on the semiconductor film formed on the substrate effectively, the method to convert the shape of the laser light emitted from the continuous oscillation laser into the line shape or the elliptical shape by an optical system, and scan the converted beam to the substrate is employed. In addition, a galvanometer mirror is used as a means to scan the laser light. That is, the laser light which is incident into the galvanometer mirror is deflected to the direction of the substrate and by oscillating the galvanometer mirror to control the incident angle and reflecting angle of the laser light to the galvanometer mirror, the deflected laser beam can be scanned to the whole surface of the substrate. With the structure that the laser light can be scanned only by oscillating the galvanometer mirror, it is not necessary any more to move the substrate back and forth by a stage and the like, and thereby it becomes possible to perform laser irradiation in a short period of time. It becomes possible to focus the beam deflected by the galvanometer mirror constantly on the plane surface by converging with an fθ lens. The beam deflected by the galvanometer mirror is scanned from the edge to the center of the lens and thereby the beam is scanned on the substrate arranged on the plane surface, that is, the semiconductor film. However, the transmissivity of the fθ lens used as a means converging laser light is different in the center and the edge thereof. Therefore, when the fθ lens is used as it is for crystallization by a laser, energy distribution of the laser light irradiated on the semiconductor film is not uniform and thereby the laser light cannot be irradiated uniformly on the whole semiconductor film. When irradiating the laser light on the semiconductor film, however, the semiconductor film needed to be processed uniformly by irradiating the laser light uniformly. Therefore, an object of the present invention is to provide the laser irradiation apparatus of continuous oscillation that can perform a laser irradiation effectively and uniformly. That is to say, the present invention provides the means to offset the difference in the energy distribution due to the difference of the transmissivity of the above lens and homogenize the irradiation energy of the laser light on the surface to be irradiated. In view of the problem mentioned above, the present invention is characterized in that the difference in the energy distribution of the laser light on the object to be irradiated is corrected by the scanning speed of the laser light. It is noted that the laser irradiation apparatus according to the present invention has a laser oscillator (a first means) and an optical system (a second means) to convert the laser light emitted from the laser oscillator. The laser light converted by the optical system is irradiated on the object to be irradiated by a third means to deflect the beam to the direction of the substrate. Moreover, the apparatus according to the present invention has a fourth means to converge the laser light on the substrate. In the structure of the present invention there is a fifth means to control the operating speed of the third means with the purpose to offset the difference in the energy of the beam due to the fourth means. It is noted that the deflection is made by giving the laser beam a phase changing that has straight line grade in the cross section of the laser beam. For example, when the plane mirror is rotated by θ to the incident light, the reflection light is deflected by 2θ. A rotatory reflection-type light deflector and a rotatory polygonal mirror are manufactured by applying this, and a galvanometer mirror and a polygon mirror are given as its examples. In other words, the laser irradiation apparatus according to the present invention which includes a galvanometer mirror and an fθ lens can scan the laser light while offsetting the change of the energy due to the transmissivity change of the fθ lens and suppressing the fluctuation of the energy on the object to be irradiated. It is noted that a polygon mirror may be used instead of the galvanometer mirror. In addition, the object to be irradiated is the semiconductor film formed on the substrate for example, but the semiconductor film is vanishingly thin when compared with the substrate. Therefore, the object to be irradiated is explained as the substrate. In the above structure, the beam is scanned by the galvanometer mirror, but usually due to the difference in the transmissivity of the lens, the energy is highest in the vicinity of the center of the substrate, and the energy becomes attenuated toward the edge of the substrate. And the transmissivity of the lens differs continuously depending on the place in the lens so that the energy of the transmitted beam also differs continuously. Therefore, the energy of the laser light irradiated on the surface to be irradiated of the substrate increases or decreases according to the scanning speed of the laser light. For this reason the present invention is characterized in that the operating speed of the galvanometer mirror (the speed to oscillate the galvanometer mirror) is changed continuously in accordance with the transmissivity of the place in the lens where the laser light is incident. As for the concrete operating speed of the galvanometer mirror, in the place in the lens where transmissivity is high, the scanning speed is set to be high. On the other hand, in the place in the lens where transmissivity is low, the scanning speed is set to be low. As a result, the energy irradiated on the substrate can be controlled. That is, the energy fluctuation of the laser light irradiated on the substrate can be prevented by controlling the scanning speed of the beam so as to offset the change of the transmissivity in the lens. With the laser irradiation apparatus of the present invention above, the laser light can be irradiated to the substrate at high speed. In addition, the whole surface of the substrate can be crystallized uniformly. It is noted that according to the present invention, even the difference of the energy distribution not due to the optical system like the fθ lens or the galvanometer mirror can be corrected by the scanning speed of the laser light. For example, even in the case that the substrate cannot be arranged evenly and is warped from the center to the edge of the substrate, the difference in the energy distribution can be corrected by controlling the scanning speed of the laser light. The structure of the laser irradiation apparatus according to the present invention is explained as follows. FIG. 1 shows the outline of the laser irradiation apparatus of the present invention. The laser irradiation apparatus 100 according to the present invention includes the laser oscillator 101 corresponding to the first means to oscillate the laser light. It is noted that FIG. 1 indicates an example providing one laser oscillator 101, however the number of the laser oscillator 101 in the laser irradiation apparatus 100 of the present invention is not limited to one. When a plurality of laser oscillators is used, the beam spots can be unified by overlapping each beam spot of the laser light emitted from each laser oscillator. The laser can be changed appropriately depending on the purpose of the process. In the present invention, the known laser can be used. The continuous oscillation gas laser or solid laser can be used as the laser oscillator. An Ar laser and a Kr laser and the like are given as the gas laser. A YAG laser, a YVO4 laser, a YLF laser, a YAlO3 laser, a Y2O3 laser, an Alexandrite laser, and a Ti: Sapphire laser and the like are given as the solid laser. The harmonic with respect to the fundamental can be obtained by using a non-linear optical element. In addition, after infrared laser light emitted from the solid laser is converted into green laser light by using the non-linear optical element, the green laser light is further converted into ultraviolet laser light by using another non-linear optical element. And this ultraviolet laser light can be used in this embodiment. Moreover, the laser irradiation apparatus 100 includes an optical element 102 corresponding to the second means that can convert the beam spot on the object to be irradiated of the laser light emitted from the laser oscillator 101. The shape of the beam spot of the laser light emitted from the laser oscillator 101 on the object to be irradiated 106 is line shape or elliptical shape. It is noted that the shape of the laser light emitted from the laser depends on the kind of the laser. In the case of a YAG laser, when the rod shape is cylindrical, the shape of the laser light becomes circular. On the other hand, when the rod shape is slab type, it becomes rectangular. It is noted that when the laser light is emitted from the slab type laser, its shape is changed significantly depending on the distance from the exit wound of the laser, because the divergence angle of the beam differs vastly in lengthwise and crosswise direction. The laser light like this can be converted into line shaped or elliptical shaped laser light in a desired size by the optical system 102. Moreover, when plural laser oscillators are used, the beam spots emitted from these laser oscillators may be overlapped each other in order to form one beam spot. The laser irradiation apparatus 100 of the present invention includes a galvanometer mirror 103 corresponding to the third means to determine the irradiation position of the laser light with respect to the object to be irradiated. By operating the galvanometer mirror 103 so as to change the incident angle and the reflecting angle of the laser light, the irradiation position of the laser light on the object to be irradiated can be moved (scanned), or the scanning direction of the laser light can be changed. The laser light can be scanned on the whole surface of the object to be irradiated by operating the galvanometer mirror 103. In addition, the laser irradiation apparatus 100 of this invention includes the optical system 104 corresponding to the fourth means. The optical system 104 includes a function to converge the beam spot of the laser light on the object to be irradiated. An fθ lens is used as the optical system 104. The beam spot can be constantly focused on the substrate by using the fθ lens. That the beam spot is constantly focused on the substrate does not always mean that the focal point of the laser light irradiated through the fθ lens is on the substrate, but includes the state that the focal point is displaced on purpose from the substrate. By displacing the focal point from the substrate like this, the surface to be irradiated becomes large, and the processing speed of the laser irradiation is increased. Therefore, the fθ lens includes the function to keep the shape of the laser light constant as desired on the whole surface of the substrate. In addition, a telecentric fθ lens can be used instead of the fθ lens. By using the telecentric fθ lens, the incident angle with respect to the object to be irradiated after transmitted through the lens is made constant, and the reflectance of the object to be irradiated can be kept constant. Moreover, the laser irradiation apparatus 100 of the present invention includes the control device 105 corresponding to the fifth means. The control device 105 can operate the galvanometer mirror 103 corresponding to the third means so that the laser light can be irradiated on the whole object to be irradiated. In addition, the difference in the beam energy due to the difference of the transmissivity of the optical system 104 can be offset by changing and controlling its operating speed continuously. And a semiconductor device in which a variation of electric characteristics is reduced can be obtained by performing laser annealing using the laser irradiation apparatus of the present invention. FIG. 2 shows an example of the laser irradiation apparatus according to the present invention. The laser beam emitted from the laser oscillator 201 is converted into a line shaped beam through a beam expander 202 and a cylindrical lens 203. A galvanometer mirror 204 and an fθ lens 205 are arranged over the substrate 210. The beam reflected by the galvanometer mirror 204 is incident into the fθ lens 205. The converted line shaped beam can be constantly focused on the substrate by the fθ lens 205. It is noted that a telecentric lens may be used as the fθ lens 205. The incident angle of the laser light to the substrate can be kept constant by the telecentric lens regardless of the place in the lens where the laser light is incident and thereby the reflectance of the object to be irradiated can be also kept constant. It is noted that in the case that the laser light is irradiated on the substrate like a glass substrate where the laser light is transmitted, an interference fringe may appear because of the reflection from the surface of the substrate and the reflection from the rear surface of the substrate. Therefore, it is also good to take the structure that the laser light is incident obliquely into the substrate. The laser light is scanned along the X-axis direction in the FIG. 2 by the galvanometer mirror 204. After the scanning along the X-axis direction is done, the substrate is shifted by the width of the beam along the Y-axis direction by the movable stage 206 and the scanning by the galvanometer mirror 204 is performed repeatedly. Thus the laser light can be irradiated on the whole surface of the substrate. As for the scanning of the laser light, the method for scanning the line shaped laser light by moving the X-axis back and forth as shown in FIG. 3A, or the method for scanning in one direction as shown in FIG. 3B may be employed. Here, the scanning speed of the laser light by the galvanometer mirror 204 is explained. First, the operating speed of the galvanometer mirror 204 is controlled to keep the scanning speed of the laser light on the substrate constant. In this case, the transmissivity depends on the place in the lens and thereby the energy of the laser light also changes according to the change of the transmissivity. FIG. 4 shows an example of the change in the irradiation energy of the laser light scanned on the substrate. FIG. 4 indicates that the laser intensity is high in the vicinity of the center of the substrate. On the other hand, the laser intensity is low in the vicinity of the edge of the substrate. Therefore, it becomes possible to suppress the change of the irradiation energy on the substrate by increasing the scanning speed of the beam in the vicinity of the center of the substrate where the transmissivity of the lens is high, and decreasing the scanning speed of the beam in the vicinity of the edge of the substrate where its transmissivity is low. In addition, FIG. 5 shows an example of the distribution of the scanning speed of the laser light that can offset the energy change of the beam shown in FIG. 4. With the apparatus of the present invention, the laser light can be scanned with the distribution shown in FIG. 5. Concretely, the case that the transmissivity of the place in the fθ lens where the laser light is incident when scanned on the center of the substrate differs by 5% from that when scanned on the edge thereof is explained. For example, when a semiconductor film having a thickness of 540 nm is irradiated by the laser light of 532 nm wavelength with the 6.5 W output emitted from a YVO4 laser at the constant scanning speed, there is a gap between the energy irradiated on the center of the substrate and that on the edge of the substrate. Therefore the width of the large-size grain region (the region where the size of the crystal grain is not less than 10 μm) formed in the region of the semiconductor film where the laser light is irradiated (the surface to be irradiated) differs in the center and in the edge of the substrate. Consequently, in order to keep the width of the large-size grain region 180 μm constantly in both the center and the edge of the substrate, the laser light is scanned at the speed of 40 cm/sec in the edge of the substrate, while 42 cm/sec in the center of the substrate. By changing the scanning speed like this, the change in the irradiation energy on the substrate can be suppressed and the width of the large-size grain region is kept constant. It is noted that in the apparatus of the present invention, the scanning speed is not limited to that mentioned above. The scanning speed may be determined depending on the conditions like the width of the large-size grain region, material of the semiconductor film, the thickness of the film and the like as desired. Moreover, the scanning speed of the laser light is controlled by controlling the operating speed of the galvanometer mirror. By irradiating with the structure above, the change in the irradiation efficiency and the fluctuation in annealing effect on the substrate due to the change of the transmissivity in the lens can be suppressed. It is noted that the pattern for modifying the speed in accordance with the various lens may be stored in advance in the control device of the galvanometer mirror so that the operating speed of the galvanometer mirror may be determined in accordance with the lens shape or its material. In addition, the change in the irradiation energy of the laser light scanned on the substrate shown in FIG. 4 is just one of the examples. Even in the case that the change in the energy is undulate as shown in FIG. 8, the present invention can be also applied. In this embodiment, the case that the scanning of the laser light in the embodiment 1 is performed by controlling the galvanometer mirror in both X-axis and Y-axis direction is explained. The scanning speed of the laser light by the galvanometer mirror is explained. First, the operating speed of the galvanometer mirror is controlled so as to keep the scanning speed of the laser light on the substrate constant. Since the transmissivity depends on the place in the lens in this case, the energy of the laser light scanned also depends on the change of the transmissivity. FIG. 6 shows an example of the change in the irradiation energy of the laser light scanned on the substrate in this case. FIG. 6 indicates that the laser intensity is high in the vicinity of the center of the substrate and it becomes attenuated toward the edge of the substrate concentrically. Therefore, the change in the irradiation energy on the substrate can be suppressed by increasing the scanning speed in the vicinity of the center of the substrate where the transmissivity is high, and decreasing the scanning speed in the edge of the substrate where the transmissivity is low. FIG. 7 shows an example of the distribution of the scanning speed of the laser light that can offset the change in the beam energy shown in FIG. 6. In the apparatus of the present invention, the laser light is scanned with the distribution shown in FIG. 7. It is noted that the scanning speed of the laser light is controlled by controlling the operating speed of the galvanometer mirror. By irradiating with the above structure, the change in the irradiation efficiency and the fluctuation in annealing effect on the substrate due to the change of the transmissivity in the lens can be suppressed. It is noted that the pattern for modifying the speed in accordance with the various lens may be stored in advance in the control device of the galvanometer mirror so that the operating speed of the galvanometer mirror may be determined in accordance with the lens shape or its material. In addition, it is preferable that the fluctuation in the beam energy irradiated on the substrate is within ±5% in order to irradiate the substrate uniformly. The fluctuation in the irradiation energy of the laser light scanned on the substrate shown in FIG. 6 is just one of the examples. Even in the case that the fluctuation in the energy is undulate as shown in FIG. 8, the present invention can be also applied. As mentioned above, according to the present invention, when crystallizing the semiconductor film on the substrate, the change in the irradiation energy on the substrate can be suppressed to keep the width of the large-size grain region formed in the region where the laser light is irradiated constant by changing the scanning speed. It is noted that the scanning speed may be controlled in accordance with the conditions and the like such as the width of the large-size grain, the material of the semiconductor film, and the thickness of the film as desired. In this embodiment, a process up to manufacture a semiconductor device with the crystalline semiconductor film by using the laser irradiation apparatus of the present invention is described with FIG. 10 and FIG. 11. First of all, base films 1001a and 1001b are formed on the substrate 1000. As the substrate 1000, an insulating substrate such as a glass substrate, a quartz substrate, or a crystalline glass substrate, or a ceramic substrate, a stainless substrate, a metal substrate (tantalum, tungsten, molybdenum, and the like), a semiconductor substrate, a plastic substrate (polyimide, acrylic, polyethylene terephthalate, polycarbonate, polyarylate, polyether sulfon and the like) can be used. It is noted that the substrate shall be made from the material that can resist the heat generated through the processes. A glass substrate is used in this embodiment. As the base films 1001a and 1001b, a silicon oxide film, a silicon nitride film or a silicon oxynitride film can be used and these insulating films may be formed in a single-layer structure or laminated-layer structure of two or more layers. These films are formed by the known method such as a sputtering method, a low-pressure CVD method, or a plasma CVD method. The films are laminated as a laminated-layer structure of two layers in this embodiment but a single-layer structure or a laminated-layer structure of three or more layers does not lead to any problems. In this embodiment, the silicon nitride oxide film is formed 50 nm in thickness as a first layer of the insulating film 1001a, and the silicon oxynitride film is formed 100 nm in thickness as a second layer of the insulating film 1001b. It is noted that the difference between the silicon nitride oxide film and the silicon oxynitride film is defined that the ratio of nitrogen and oxygen contained in those films is different, and the silicon nitride oxide film contains more nitrogen than oxygen. Next, an amorphous semiconductor film is formed. The amorphous semiconductor film may consist of silicon or the silicon based material (SixGe1-x and the like, for example) from 25 nm to 80 nm in thickness. As for its forming means, the known method such as the sputtering method, the low-pressure method, or the plasma CVD method can be employed. In this embodiment, the amorphous silicon film is formed 66 nm in thickness (FIG. 10A). Then the crystallization of the amorphous silicon is performed. In this embodiment, a process to perform laser annealing is explained as the method for crystallization (FIG. 10B). The laser irradiation apparatus of the present invention is used to perform the laser annealing. The continuous oscillation gas laser or solid laser can be used as the laser oscillator apparatus. An Ar laser, a Kr laser and the like are exemplified as the gas laser and a YAG laser, a YVO4 laser, a YLF laser, a YAlO3 laser, an Alexandrite laser, a Ti: Sapphire and the like are exemplified as the solid laser. One kind or plural kinds selected from the group consisting of Cr3+, Cr4+, Nd3+, Er3+, Ce3+, Co2+, Ti3+, Yb3+ and V3+ is/are doped as impurity in the crystal which is a laser medium of the solid laser. The laser annealing is performed to crystallize the amorphous silicon by the laser irradiation apparatus of the present invention. More concretely, the laser annealing is performed by the method as described in the embodiment 1 and 2. In this embodiment, a YVO4 laser (532 nm wavelength) with 10 W output is used and the laser light is converted into elliptical shaped laser light of 20 μm in minor axis and of 750 μm in major axis and the incident angle of the laser light to the surface to be irradiated is set to 30°. The scanning speed of the laser light is changed so as to offset the change in the irradiation energy due to the transmissivity change of the fθ lens. By changing the scanning speed as mentioned above, the change in the irradiation energy on the substrate can be suppressed and the width of the large-size grain region can be kept constant. In addition, when the semiconductor film after crystallized is used as an active layer of TFT, it is preferable that the scanning direction of the laser light is set to be parallel to the shifting direction of the carrier in the channel forming region. Consequently, the scanning direction of the laser light is determined to be parallel to the shifting direction of the carrier (channel length direction) in the channel forming region as indicated by an arrow shown in FIG. 9. Therefore, the crystal grows along the scanning direction of the laser light and thereby it can be prevented that the grain boundary crosses the channel length direction. Next, the crystalline semiconductor film is converted into the desired shape 1002a through 1002d by etching (FIG. 10C). Then a gate insulating film 1003 is formed (FIG. 10D). The film thickness is set to be about 115 nm, and the insulating film including silicon may be formed by the low-pressure CVD method, the plasma CVD method, the sputtering method or the like. In this embodiment, a silicon oxide film is formed. In this case, it is formed by the plasma CVD method with a mixture of TEOS (Tetraethyl Orthosilicate) and O2 at a reaction pressure of 40 Pa, with the substrate temperature set between 300° C. and 400° C., and by discharging at a high frequency (13.56 MHz) electric power density from 0.5 W/cm2 to 0.8 W/cm2. The silicon oxide film which is thus formed gives good characteristics as a gate insulating film by subsequently performing heating process at between 400° C. and 500° C. By crystallizing the semiconductor film using the laser irradiation apparatus of the present invention, the crystalline semiconductor with good and uniform characteristics can be obtained. Next, tantalum nitride (TaN) is formed 30 nm in thickness as a first conductive layer on the gate insulating film, and tungsten (W) is formed 370 nm in thickness as a second conductive layer on the first conductive layer. Both the TaN film and the W film may be formed by the sputtering method, and the TaN film is formed by the sputtering using a target of Ta in a nitrogen atmosphere. Further, the W film is formed by sputtering using a target of W. It is necessary to make the film become low resistant in order to use it as a gate electrode, and it is preferable that the resistivity of the W film is made not more than 20 μΩcm. For this reason, it is preferable that the target for the W film is high-purity (99.9999%) and full attention must be paid so that the impurity element is not mixed when the film is formed. The resistivity of the W film thus formed can be made from 9 μΩcm to 20 μΩcm. It is noted that although in this embodiment the first conductive layer consists of TaN having a thickness of 30 nm, and the second conductive layer consists of W having a thickness of 370 nm, there is no particular limitation for the material of the conductive layers. Both the first conductive layer and the second conductive layer may be formed of the elements selected from the group consisting of Ta, W, Ti, Mo, Al, Cu, Cr, and Nd, or of an alloy material or a chemical compound having one of these elements as its main constituent. Further, a semiconductor film, typically a polycrystalline silicon film in which an impurity element such as phosphorus is doped may be also used, as may an AgPdCu alloy. Moreover, the combination of these can be applied appropriately. The first conductive layer may be formed from 20 nm to 100 nm in thickness. On the other hand, the second conductive layer may be formed from 100 nm to 400 nm in thickness. In addition, a laminated-layer structure of two layers is employed in this embodiment, but a single-layer structure or a laminated-layer structure of three or more layers can be also employed. Next, a mask made from resist is formed through an exposure process by a photolithography method in order to form electrodes and wirings by etching the conductive layers. The first etching process is performed in accordance with first and second etching conditions. The etching process is performed by using the mask made from resist, and the gate electrodes and the wirings are thus formed. The etching conditions are selected appropriately. An ICP (Inductively Coupled Plasma) etching method is employed in this embodiment. The etching process is performed under the first etching condition in which a mixed gas of CF4, Cl2 and O2 is used as an etching gas with the gas flow rate 25:25:10 (sccm) respectively, and plasma is generated by applying 500 W RF (13.56 MHz) electric power to a coil shaped electrode at a pressure of 1.0 Pa. 150 W RF (13.56 MHz) electric power is also applied to the substrate side (sample stage), and thereby substantially a negative self-bias voltage is impressed. The W film is etched under the first etching condition, and the edge portions of the first conductive film are made into a tapered shape. In the first etching condition, the etching speed to the W film is 200.39 nm/min. On the other hand, the etching speed to the TaN film is 80.32 nm/min and the selected ratio of the W film to the TaN film is about 2.5. And the angle of the tapered portions in the W film becomes 26° according to the first etching condition. Next the etching process is performed under the second etching condition without removing the mask made from resist. In the second etching condition, a mixed gas of CF4 and Cl2 is used as an etching gas with the gas flow rate 30:30 (sccm) and plasma is generated by applying 500 W RF (13.56 MHz) to a coil shaped electrode at a pressure of 1.0 Pa. The etching process is performed for about 15 seconds. 20 W RF (13.56 MHz) electric power is also applied to the substrate side (sample stage), and thereby substantially a negative self-bias voltage is impressed. Under the second etching condition using the mixed gas of CF4 and Cl2, the W film and the TaN film are both etched to the same extent. In the second etching condition, the etching speed to the W film is 58.97 nm/min, while the etching speed to the TaN film is 66.43 nm/min. It is noted that in order to perform the etching process without leaving a residue on the gate insulating film, the time for etching is increased by 10% to 20%. Through the first etching process, the gate insulating film which is not covered by the electrode is etched by about 20 nm to 50 nm. In the first etching process described above, the end portions of the first and second conductive layers are made into tapered shapes due to the bias voltage impressed to the substrate side. Next a second etching process is performed without removing the mask made from resist. The second etching process is performed under the condition in which a mixed gas of SF6, Cl2 and O2 is used as an etching gas with the gas flow rate 24:12:24 (sccm) respectively, and plasma is generated by applying 700 W RF (13.56 MHz) electric power to a coil shaped electrode at a pressure of 1.3 Pa. The etching process is performed for approximately 25 seconds. 10 W RF (13.56 MHz) electric power is also applied to the substrate side (sample stage), and thereby substantially a negative self-bias voltage is impressed. The W film is selectively etched under this etching condition, and the second shaped conductive layer is formed. The first conductive layer is hardly etched in this process. Through the first and second etching processes, the gate electrode consisting of the first conductive layer 1004a to 1004d and the second conductive layer 1005a to 1005d are formed (FIG. 11A). Then a first doping process is performed without removing the mask made from resist. The impurity element which imparts n-type is doped in the crystalline semiconductor layer at a low concentration through this process. The first doping process may be performed by ion doping method or ion implantation method. Ion doping process is performed under the condition in which the dosage is set from 1×1013 atoms/cm2 to 5×1014 atoms/cm2, and the acceleration voltage is set from 40 kV to 80 kV. In this embodiment, the acceleration voltage is set to 50 kV. An element belonging to the 15th elements in the periodic table, typically phosphorus (P) or arsenic (As) is used as an impurity element which imparts n-type. Phosphorus (P) is used in this embodiment. Then a first impurity region (N-region) doped low concentrated impurity is formed in a self-aligning manner by using the first conductive layer as the mask. Next, the mask made from resist is removed. Then the mask made from resist is newly formed, and a second doping process is performed at the higher acceleration voltage than that in the first doping process. The impurity which imparts n-type is doped also through the second doping process. Ion doping is performed under the conditions in which the dosage is set from 1×1013 atoms/cm2 to 3×1015 atoms/cm2, and the acceleration voltage is set between 60 kV and 120 kV. In this embodiment, the dosage is set to 3×1015 atoms/cm2 and the acceleration voltage is set to 65 kV. The second conductive layer is used as a mask against the impurity element through the second doping process and the doping process is performed so that the impurity element is doped also in the semiconductor layer provided below the first conductive layer. After performing the second doping process, the second impurity region (N− region, Lov region) is formed on the portion which is not overlapped with the second conductive layer or which is not covered by the mask among the portions which is overlapped with the first conductive layer in the crystalline semiconductor layer. The impurity which imparts n-type is doped to the second impurity region at the concentration in a range of 1×1018 atoms/cm3 to 5×1019 atoms/cm3. In addition, the impurity which imparts n-type is doped to the portions which are exposed without being covered by both the first shaped conductive layer and the mask (a third impurity region: N+ region) at the high concentration in a range of 1×1019 atoms/cm3 to 5×1021 atoms/cm3. It is noted that N+ region exists in the semiconductor layer but there is a portion which is covered by only the mask. Since the concentration of the impurity which imparts n-type in this portion stays the same as that when doped in the first doping process, it can be still called the first impurity region (N−− region). The impurity regions are formed by performing the doping process twice in this embodiment, but the number of times for performing it is not limited and depends on the conditions. The conditions are appropriately set so as to form the impurity region at the desired concentration by performing the doping process once or plural times. Then after removing the mask made from resist, the mask made from resist is newly formed and a third doping process is performed. Through the third doping process, a fourth impurity region (P+ region) and a fifth impurity region (P− region) which are doped impurity element that imparts the opposite conductivity type of the first and second conductivity type are formed in the semiconductor layer which becomes P-channel type TFTs. Through the third doping process, the fourth impurity region (P+ region) is formed on the portion which is not covered by the mask made from resist and further is not overlapped with the first conductive layer. And the fifth impurity region (P− region) is formed on the portion which is not covered by the mask made from resist and which is overlapped with the first conductive layer but not overlapped with the second conductive layer. An element belonging to the 13th elements in the periodic table, typically boric acid (B), aluminum (Al), gallium (Ga) or the like is known as the impurity which imparts p-type. In this embodiment, the fourth impurity region and the fifth impurity region are formed by the ion doping method using diborane (B2H6) by selecting boric acid (B) as the impurity which imparts p-type. As the conditions of the ion doping method, the dosage is set to 1×1016 atoms/cm2 and the acceleration voltage is set to 80 kV. It is noted that the semiconductor layer to form the N-channel TFT is covered by the mask made from resist through the third doping process. Through the first and the second doping processes, phosphorus (P) is doped in the fourth impurity region (P+ region) and the fifth impurity region (P− region) at the different concentration respectively. However, in both the fourth impurity region (P+ region) and the fifth impurity region (P− region), the third doping process is performed so that the impurity element which imparts p-type is doped at the concentration in a range of 1×1019 atoms/cm2 to 5×1021 atoms/cm2. Therefore, the fourth impurity region (P+ region) and the fifth impurity region (P− region) work as the source region or the drain region without any problems. It is noted that in this embodiment, the fourth impurity region (P+ region) and the fifth impurity region (P− region) are formed by performing the third doping process once, but the number of times to perform it is not limited to this. The doping process may be performed plural times appropriately depending on its conditions to form the fourth impurity region (P+ region) and the fifth impurity region (P− region). By performing these doping processes, the first impurity region (N−− region) 1120b, the second impurity region (N− region, Lov region) 1110b, the third impurity region (N+ region) 1110a, 1120a, the fourth impurity region (P+ region) 1130a, 1140a, and the fifth impurity region (P− region) 1130b, 1140b are formed (FIG. 11B). Next, after removing the mask made from resist, a first passivation film 1200 is formed. The insulating film including silicon is formed from 100 nm to 200 nm in thickness as the first passivation film 1200. The plasma CVD method or the sputtering method can be employed as its forming method. In this embodiment, a silicon oxynitride film is formed 100 nm in thickness by the plasma CVD method. In the case to use the silicon oxynitride film, the silicon oxynitride film consisting of SiH4, N2O and NH3 or the silicon oxynitride film consisting of SiH4 and N2O may be formed by the plasma CVD method. In this case, these films are formed under the conditions at a reaction pressure from 20 Pa to 200 Pa, with the substrate temperature set between 300° C. and 400° C., and by discharging at a high frequency (60 MHz) electric power density from 0.1 W/cm2 to 1.0 W/cm2. In addition, the silicon oxynitride hydride film consisting of SiH4, N2O and H2 may be applied as the first passivation film 1200. Of course, the first passivation film 1200 is not limited to the single-layer structure of the silicon oxynitride film as shown in this embodiment. The insulating film including silicon may be used for a single-layer structure or the laminated-layer structure as the first passivation film 1200. After that, a heating process is performed to recover the crystallinity of the semiconductor layer and activate the impurity elements doped in the semiconductor layer. The heating process may be performed in the nitrogen atmosphere with the oxygen concentration of not more than 1 ppm, preferably not more than 0.1 ppm, at the temperature between 400° C. and 700° C. In this embodiment, the heating process is performed at the temperature of 410° C. for one hour in order to perform activating process. It is noted that, in addition to the heating process, laser annealing method, or rapid thermal annealing method (RTA method) can be also applied. Furthermore, by performing the heating process after forming the first passivation film 1200, hydrogenation of the semiconductor film can be performed at the same time of activating process. Hydrogenation is performed in order to terminate the dangling bond of the semiconductor layer by hydrogen included in the first passivation film 1200. Moreover, the heating process may be performed before forming the first passivation film 1200. However, it is noted that in the case that the materials used in the first conductive layer 1040a to 1040d and the second conductive layer 1050a to 1050d are of low-resistance against heat, it is preferable that the heating process is performed after forming the first passivation film 1200 in order to protect the wirings and the like as shown in this embodiment. Further, in this case, hydrogenation by applying the hydrogen contained in the passivation film 1200 cannot be performed because there is not the first passivation film 1200. In this case, hydrogenation by applying hydrogen excited by plasma (plasma hydrogenation), or hydrogenation by the heating process in the atmosphere including the hydrogen of 3% to 100% at the temperature between 300° C. and 450° C. for 1 hour to 12 hours may be conducted. Next, a first interlayer insulating film 1210 is formed on the first passivation film 1200. An inorganic insulating film or an organic insulating film may be used as the first interlayer insulating film 1210 (FIG. 11C). As the inorganic insulating film, the silicon oxide film formed by the CVD method, the silicon oxide film formed by the SOG (Spin On Glass) method or the like may be used. As the organic insulating film, polyimide, polyamide, BCB (benzocyclobutene), acrylic, or positive type photosensitive organic resin, negative type photosensitive organic resin or the like can be used. In addition, the laminated-layer structure of the acrylic film and the silicon oxynitride film may be employed. Moreover, the interlayer insulating film can be formed of the material including at least hydrogen in the substituent and with the structure in which silicon (Si) and oxygen (O) are bond. Furthermore, the interlayer insulating film can be formed of the material with at least one selecting from the group consisting of fluorine, alkyl group, and aromatic hydrocarbon in the substituent. The representative example is siloxanic polymer. Siloxanic polymer can be classified into silica-glass, alkyl siloxanic polymer, alkyl silceschioxanic polymer, silceschioxanic polymer hydride, alkyl silceschioxanic polymer hydride and the like by its structure. In addition, the interlayer insulating film may be formed of the material including the polymer with Si—N bond (polysilazane). By using the above material, even though the interlayer insulating film is made to be thinner, the interlayer insulating film with sufficient insulating property and evenness can be obtained. Moreover, since the above material shows high-resistance against heat, the interlayer insulating film which can resist through reflowing process in the multilayers wirings. Furthermore, because its hygroscopic property is low, the interlayer insulating film with small dehydration amount can be formed. In this embodiment, the non-photosensitive acrylic film having a thickness of 1.6 μm is formed. The unevenness by TFT formed on the substrate can be modified and be made even by the first interlayer insulating film. Especially since the first interlayer insulating film is provided mainly for planarization, the insulating film formed of the material which is easily planarized is preferable. After that, a second passivation film (not shown in the figure) consisting of a silicon nitride oxide film and the like is formed on the first interlayer insulating film from 10 nm to 200 nm in thickness approximately. The second passivation film can suppress the moisture moving in and out of the first interlayer insulating film. The second passivation film may be formed of a silicon nitride film, an aluminum nitride film, an aluminum oxynitride film, a diamond-like carbon (DLC) film, or a carbon nitride (CN) film as well. In addition, the film formed by the RF sputtering method is extremely precise, and is superior in its barrier property. When forming the silicon oxynitride film for example, the film is formed under the conditions for the RF sputtering where the Si is used as a target, the mixed gas of N2, Ar, and N2O is set to 31:5:4 at the gas flow rate respectively, the pressure is 0.4 Pa and the electric power is 3000 W. Furthermore, when forming the silicon nitride film, the film is formed under the conditions where the Si is used as a target, the mixed gas of N2 and Ar is set to 20:20 at the gas flow rate respectively, the pressure is 0.8 Pa, the electric power is 3000 W and the temperature in forming film is set to 215° C. In this embodiment, the silicon oxynitride film is formed 70 nm in thickness by the RF sputtering method. Next, the second passivation film, the first interlayer insulating film and the first passivation film are etched (by performing the etching process) to form a contact hole that reaches the third and the fourth impurity region. After that, the wirings and the electrodes (1220 to 1290) that connect with each impurity region electrically are formed. It is noted that these wirings are formed by patterning the laminated-layer film consisting of the Ti film having a thickness of 50 nm and the alloy film (Al and Ti) having a thickness of 500 nm. Of course, it is not limited to the laminated-layer structure of two layers, but a single-layer structure or a laminated-layer structure of three or more layers may be applied. Moreover, the material for the wirings is not limited to Al and Ti. For example, the wirings are formed by patterning the laminated-layer film where an Al film or a Cu film is formed on the TaN film, and a Ti film is further formed thereon. As shown above, when the semiconductor device is manufactured by using the laser irradiation apparatus of the present invention, it shows good and uniform characteristic, and thereby it can be applied to various electrical devices, especially a display device preferably. Moreover, the reliability of such devices can be highly improved. The laser irradiation apparatus using the galvanometer mirror and the fθ lens can perform the processes to the substrate in a short period of time. The operating speed of the galvanometer mirror is controlled and the scanning speed of the laser light is changed continuously so that the change in transmissivity of the lens is offset. With the structure above, it becomes possible that the laser light is irradiated while controlling the irradiation energy. Therefore, according to the present invention, the change in the energy of the laser light on the substrate can be suppressed. And the semiconductor device in which the variation in electric characteristics is decreased can be obtained by applying the laser irradiation apparatus of the present invention.
	description	For purposes of the USPTO extra-statutory requirements, the present application constitutes a continuation of U.S. patent application Ser. No. 13/373,139, entitled SYSTEMS, DEVICES, METHODS, AND COMPOSITIONS INCLUDING FLUIDIZED X-RAY SHIELDING COMPOSITIONS, naming Philip A. Eckhoff, William H. Gates III, Peter L. Hagelstein, Roderick A. Hyde, Jordin T. Kare, Robert Langer, Erez Lieberman, Eric C. Leuthardt, Nathan P. Myhrvold, Michael Schnall-Levin, Clarence T. Tegreene, Lowell L. Wood, Jr. as inventors, filed 3, Nov. 2011, which is currently co-pending or is an application of which a currently co-pending application is entitled to the benefit of the filing date. The United States Patent Office (USPTO) has published a notice to the effect that the USPTO's computer programs require that patent applicants reference both a serial number and indicate whether an application is a continuation, continuation-in-part, or divisional of a parent application. Stephen G. Kunin, Benefit of Prior-Filed Application, USPTO Official Gazette Mar. 18, 2003. The present Applicant Entity (hereinafter “Applicant”) has provided above a specific reference to the application(s) from which priority is being claimed as recited by statute. Applicant understands that the statute is unambiguous in its specific reference language and does not require either a serial number or any characterization, such as “continuation” or “continuation-in-part,” for claiming priority to U.S. patent applications. Notwithstanding the foregoing, Applicant understands that the USPTO's computer programs have certain data entry requirements, and hence Applicant has provided desigmation(s) of a relationship between the present application and its parent application(s) as set forth above, but expressly points out that such designation(s) are not to be construed in any way as any type of commentary and/or admission as to whether or not the present application contains any new matter in addition to the matter of its parent application(s). The present application is related to and claims the benefit of the earliest available effective filing date(s) from the following listed application(s) (the “Related Applications”) (e.g., claims earliest available priority dates for other than provisional patent applications or claims benefits under 35 USC §119(e) for provisional patent applications, for any and all parent, grandparent, great-grandparent, etc. applications of the Related Application(s)). All subject matter of the Related Applications and of any and all parent, grandparent, great-grandparent, etc. applications of the Related Applications, including any priority claims, is incorporated herein by reference to the extent such subject matter is not inconsistent herewith. In an aspect, the present disclosure is directed to, among other things, an x-ray shielding fluid composition including a plurality of x-ray shielding particles, each having at least a first x-ray shielding agent and a second x-ray shielding agent, and a carrier fluid. In an embodiment, the second x-ray shielding agent includes one or more absorption edges different from the first x-ray shielding agent. In an embodiment, the plurality of x-ray shielding particles includes a second x-ray having one or more characteristic x-ray absorption edges different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes one or more k-edges, or one or more l-edges, different from the first x-ray shielding agent. In an embodiment, the plurality of x-ray shielding particles includes a second x-ray having an x-ray mass attenuation coefficient different from the first x-ray shielding agent. In an embodiment, the plurality of x-ray shielding particles include a second x-ray having at least one k-edge having an energy level lower than at least one k-edge of the first x-ray shielding agent In an embodiment, the plurality of x-ray shielding particles include a second x-ray having at least one k-edge or l-edge corresponding to an x-ray energy absorption minimum of the first x-ray shielding agent. In an aspect, the present disclosure is directed to, among other things, an x-ray shielding fluid composition including at least a first x-ray shielding agent and a second x-ray shielding agent, the second x-ray shielding agent having one or more absorption edges different from the first x-ray shielding agent, and a carrier fluid. In an embodiment, the x-ray shielding fluid composition includes a third x-ray shielding agent having one or more absorption edges different from the second x-ray shielding agent and the first x-ray shielding agent. In an embodiment, the x-ray shielding fluid composition includes a fourth x-ray shielding agent, the fourth x-ray shielding agent having one or more absorption edges different from the third x-ray shielding, the second x-ray shielding agent, and the first x-ray shielding agent. In an embodiment, the x-ray shielding fluid composition includes a fifth x-ray shielding agent, the fifth x-ray shielding agent having one or more absorption edges different from the fourth x-ray shielding agent, the third x-ray shielding, the second x-ray shielding agent, and the first x-ray shielding agent. In an aspect, the present disclosure is directed to, among other things, dynamic x-ray shielding garments (e.g., aprons, coats, eye protectors, gloves, neck protectors, pants, scrub caps, shirts, skirts, sleeves, socks, surgical scrubs, vests, etc.) including at least a first layer including a support structure having a plurality of interconnected interstitial spaces that provide a circulation network for an x-ray shielding fluid composition. In an embodiment, the support structure is configured to constrain the x-ray shielding fluid composition to move along one or more of the plurality of interconnected interstitial spaces. In an embodiment, a dynamic x-ray shielding garment includes at least one x-ray shielding fluid reservoir assembly including one or more x-ray shielding fluid reservoirs. In an embodiment, the x-ray shielding fluid reservoir assembly is structured and arranged to hold the x-ray shielding fluid composition and to selectively enable fluid communication between one or more x-ray shielding fluid reservoirs and the plurality of interconnected interstitial spaces. In an embodiment, the dynamic x-ray shielding garment includes an x-ray shielding fluid supply controller operable to manage fluid flow of the x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly, and along one or more of the plurality of interconnected interstitial spaces. In an aspect, the present disclosure is directed to, among other things, a dynamic x-ray shielding method including receiving x-ray potential exposure event data associated with delivery of an x-ray radiation stimulus from an x-ray radiation-emitting system. In an embodiment, the dynamic x-ray shielding method includes directing fluid flow of an x-ray shielding fluid composition received in an x-ray shielding fluid reservoir assembly associated with a dynamic x-ray shielding garment, to or from the x-ray shielding agent reservoir, and along one or more of a plurality of interconnected interstitial spaces within the dynamic x-ray shielding garment, responsive to the x-ray potential exposure event data. In an aspect, the present disclosure is directed to, among other things, an x-ray shielding method including actuating fluid flow of an x-ray shielding fluid composition received in one or more x-ray shielding fluid reservoirs associated with a dynamic x-ray shielding garment, to or from the x-ray shielding agent reservoir, and along one or more of a plurality of interconnected interstitial spaces within the dynamic x-ray shielding garment responsive to a determination that an x-ray radiation-emitting system is in operation. In an aspect, the present disclosure is directed to, among other things, an x-ray shielding method including actuating fluid flow of an x-ray shielding fluid composition received in one or more x-ray shielding fluid reservoirs associated with a dynamic x-ray shielding garment, to or from the x-ray shielding agent reservoir, and along one or more of a plurality, of interconnected interstitial spaces within the dynamic x-ray shielding garment responsive to an input associated with a potential delivery of an x-ray radiation stimulus from an x-ray radiation-emitting system. In an aspect, the present disclosure is directed to, among other things, a dynamic x-ray shielding system including an x-ray shielding fluid reservoir configured to store and supply at least a first x-ray shielding fluid composition and a second x-ray shielding fluid composition. In an embodiment, the dynamic x-ray shielding system includes at least a first layer including a first flow path in fluid communication with the x-ray shielding fluid reservoir assembly and configured to receive the first x-ray shielding fluid composition. In an embodiment, the first flow path includes a first flow valve assembly selectively actuatable between an open state which permits fluid flow through the first flow valve assembly such that the first x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly along at least a portion of the first flow path, and a restrict state which restricts fluid flow through the first flow valve assembly. In an embodiment, the dynamic x-ray shielding system includes a second layer including a second flow path in fluid communication with the x-ray shielding fluid reservoir assembly and configured to receive the second x-ray shielding fluid composition. In an embodiment, the second flow path includes a second flow valve assembly selectively actuatable between an open state which permits fluid flow through the second flow valve assembly such that the second x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly along at least a portion of the first flow path, and a restrict state which restricts fluid flow through the second flow valve assembly. In an embodiment, the dynamic x-ray shielding system includes an x-ray shielding fluid supply controller associated with at least the first flow valve assembly and the second flow valve assembly and configured to selectively actuate the first or the second flow valve assembly to regulate fluid flow of a defined quantity of at least one of the first x-ray shielding fluid composition or the second x-ray shielding fluid composition from the reservoir, through at least one of the first flow valve or the second flow valve, into the at least a portion of the first flow path or the second flow path. In an aspect, the present disclosure is directed to, among other things, a dynamic x-ray shielding method including receiving x-ray potential exposure event data associated with delivery of an x-ray radiation stimulus from an x-ray radiation-emitting system. In an embodiment, the dynamic x-ray shielding method includes concurrent or sequential actuating fluid flow of a first x-ray shielding fluid composition or the second x-ray shielding fluid, received in an x-ray shielding fluid reservoir assembly, to or from the x-ray shielding agent reservoir and along respectively one of a first flow path or a second flow path of a dynamic x-ray shielding apparatus, responsive to potential exposure event data indicative of an x-ray potential exposure event. In an aspect, the present disclosure is directed to, among other things, a dynamic x-ray shielding method including determining an actuate flow condition. In an embodiment, the dynamic x-ray shielding method includes concurrent or sequential actuating fluid flow of a first x-ray shielding fluid composition or the second x-ray shielding fluid, received in a plurality of x-ray shielding fluid reservoirs, to or from the plurality of x-ray shielding fluid reservoirs and along respectively one of a first flow path or a second flow path of a dynamic x-ray shielding apparatus, responsive to the actuate flow condition. In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. Medical systems (e.g., fluoroscopy systems, computed tomography systems, radiography systems, radiation treatment systems, x-ray imaging system, etc.) are valuable diagnostics and treatment tools in medical practice. Likewise, cabinet x-ray systems (e.g., closed x-ray systems, x-ray inspection systems, x-ray screening systems, x-ray security systems, baggage x-ray systems, etc.) are useful tools for detection of contraband, contaminants, or manufacturing defects without damaging or destroying the item being examined. Exposure to radiation may cause cancer (especially leukemia), birth defects in the children of exposed parents and cataracts. These health effects (excluding genetic effects) have been observed in studies of medical radiologists, uranium miners, radium workers, and radiotherapy patients who have received large doses of radiation. Studies of radiation effects on laboratory animals have provided a large body of data on radiation health effects including genetic effects. Most of the studies mentioned above involve acute exposure to high levels of radiation. Acute exposure can be, for example, exposure to hundreds of rem (Roentgen equivalent in man) within a few hours or less. Such radiation doses far exceed the occupational dose limits currently recommended (less than 5 rem per year). However, the major concerns today are about delayed health effects arising from chronic cumulative exposure to radiation. The major health concern from chronic cumulative exposure to radiation is cancer which may appear 5 to 20 years after exposure to relatively low levels of radiation. The current limits for radiation exposure set by the FDA for adults are: 50 mSv (millisieverts) (5 rems) per year and 30 mSv (3 rems) per single dose. (http://tech.mit.edu/Bulletins/Radiation/rad5.txt). For children, who are more vulnerable to radiation, the limits are 5 mSv (0.5 rems) annually and 3 mSv (0.3 rems) per single dose. A lifetime occupational exposure level of no greater than 400 mSv (40 rems) is recommended by government agencies (Hall et al., Canadian Fam. Physician 52: 976-77, 2006). Compliance with these radiation exposure limits is complicated by the lack of cumulative radiation exposure data, especially in regard to lifetime exposure limits. Also the increased usage of computed tomography scans for medical imaging (Brenner and Hall, N. Engl. J. Med. 357: 2277-84, 2007) has created a need for monitoring, x-ray shielding, and protecting against a radiation exposure event to avoid exceeding exposure limits. X-ray shielding fluid compositions are described with which one or more methodologies or technologies can be implemented such as, for example, providing x-ray shielding and protection. Factors affecting the radiation amount or dose received from an x-ray source include the exposure time, the distance from x-ray source, the utilization of x-ray shielding, or the like. The type and amount of material to attenuate (shield) x-ray radiation is dependent upon the energy of the x rays, the material's chemical composition, and the material's density. In an embodiment, an x-ray shielding fluid composition includes a plurality of x-ray shielding particles and a carrier fluid. Non-limiting examples of particles include glass beads having one or more x-ray shielding agents, nanoparticles having a plurality of shielding agents within a glass material matrix, particles having a plurality of elemental dopants within a material matrix, or the like. In an embodiment, each of the x-ray shielding particles includes at least a first x-ray shielding agent and a second x-ray shielding agent. In an embodiment, the plurality of x-ray shielding particles includes a third x-ray shielding agent, the third x-ray shielding agent having one or more absorption edges different from the second x-ray shielding agent and the first x-ray shielding agent. In an embodiment, the plurality of x-ray shielding particles includes a fourth x-ray shielding agent, the fourth x-ray shielding agent having one or more absorption edges different from the third x-ray shielding agent, the second x-ray shielding agent, and the first x-ray shielding agent. In an embodiment, the plurality of x-ray shielding particles includes a fifth x-ray shielding agent, the fifth x-ray shielding agent having one or more absorption edges different from the fourth x-ray shielding agent, the third x-ray shielding agent, the second x-ray shielding agent, and the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes one or more absorption edges different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes one or more characteristic x-ray absorption edges different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes one or more k-edges, or one or more l-edges, different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes an x-ray mass attenuation coefficient different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes at least one k-edge having an energy level lower than at least one k-edge of the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes at least one k-edge or l-edge corresponding to an x-ray energy absorption minimum of the first x-ray shielding agent. In an embodiment, the plurality of x-ray shielding particles includes one or more x-ray radio-opaque materials (e.g., barium sulfate, silicon carbide, silicon nitride, alumina, zirconia, etc.). In an embodiment, the plurality of x-ray shielding particles includes one or more x-ray attenuating materials. In an embodiment, the plurality of x-ray shielding particles includes one or more x-ray attenuating ceramic materials. In an embodiment, the plurality of x-ray shielding particles comprise one or ferromagnetic materials. Ferromagnetic materials include those materials having a Curie temperature, above which thermal agitation destroys the magnetic coupling giving rise to the alignment of the elementary magnets (electron spins) of adjacent atoms in a lattice (e.g., a crystal lattice). In an embodiment, one or more of the plurality of x-ray shielding particles include one or more ferromagnets. Among ferromagnetic materials, examples include, but are not limited to, crystalline ferromagnetic materials, ferromagnetic oxides, materials having a net magnetic moment, materials having a positive susceptibility to an external magnetic field, non-conductive ferromagnetic materials, non-conductive ferromagnetic oxides, ferromagnetic elements (e.g., cobalt, gadolinium, iron, or the like), rare earth elements, ferromagnetic metals, ferromagnetic transition metals, materials that exhibit magnetic hysteresis, and the like, and alloys or mixtures thereof. Further examples of ferromagnetic materials include, but are not limited to, chromium (Cr), cobalt (Co), copper (Cu), dysprosium (Dy), europium (Eu), gadolinium (Gd), iron (Fe), magnesium (Mg), neodymium (Nd), nickel (Ni), yttrium (Y), and the like. Further examples of ferromagnetic materials include, but are not limited to, chromium dioxide (CrO2), copper ferrite (CuOFe2O3), europium oxide (EuO), iron(II, III) oxide (FeOFe2O3), iron(III) oxide (Fe2O3), magnesium ferrite (MgOFe2O3), manganese ferrite (MnOFe2O3), nickel ferrite (NiOFe2O3), yttrium-iron-garnet (Y3Fe5O12), and the like. Further examples of ferromagnetic materials include, but are not limited to, manganese arsenide (MnAs), manganese bismuth (MnBi), manganese (III) antimonide (MnSb), Mn—Zn ferrite, neodymium alloys, neodymium, Ni—Zn ferrite, and samarium-cobalt. In an embodiment, one or more of the plurality of x-ray shielding particles include at least one iron oxide. Among iron oxides, examples include, but are not limited to, copper ferrite (CuOFe2O3), iron(II, III) oxide (FeOFe2O3), iron(III) oxide (Fe2O3), magnesium ferrite (MgOFe2O3), manganese ferrite (MnOFe2O3), nickel ferrite (NiOFe2O3), yttrium-iron-garnet (Y3Fe5O12), ferric oxides, ferrous oxides, and the like. In an embodiment, one or more of the plurality of x-ray shielding particles include at least one iron oxide. Among iron oxides, examples include, but are not limited to, copper ferrite (CuOFe2O3), iron(II, III) oxide (FeOFe2O3), iron(III) oxide (Fe2O3), magnesium ferrite (MgOFe2O3), manganese ferrite (MnOFe2O3), nickel ferrite (NiOFe2O3), yttrium-iron-garnet (Y3Fe5O12), ferric oxides, ferrous oxides, and the like. In an embodiment, one or more of the plurality of x-ray shielding particles are configured to include one or more magnetic components. In an embodiment, the plurality of x-ray shielding particles comprise one or ferrimagnetic materials. In an embodiment, one or more of the plurality of x-ray shielding particles include one or more ferrimagnets (e.g., soft ferrites, hard ferrites, or the like). Among ferrimagnetic materials, examples include, but are not limited to, ferrimagnetic oxides (e.g., ferrites, garnets, or the like). Further examples of ferrimagnetic materials include ferrites with a general chemical formula of AB2O4 (e.g., CoFe2O4, MgFe2O4, ZnFe2O4) where A and B represent various metal cations. In an embodiment, A is Mg, Zn, Mn, Ni, Co, or Fe(II); B is Al, Cr(III), Mn(III) or Fe(III), and O is oxygen. In an embodiment, A is a divalent atom of radius ranging from about 80 pm to about 110 pm (e.g., Cu, Fe, Mg, Mn, Zn, or the like), B is a trivalent atom of radius ranging from about 75 pm to about 90 pm, (e.g., Al, Fe, Co, Ti, or the like), and O is oxygen. Further examples of ferrimagnetic materials include iron ferrites with a general chemical formula MOFe2O3 (e.g., CoFe2O4, Fe3O4, MgFe2O4, or the like) where M is a divalent ion such as Fe, Co, Cu, Li, Mg, Ni, or Zn. Further examples of ferromagnetic materials include materials having a magnetization compensation point, materials that are associated with a partial cancellation of antiferromagnetically aligned magnetic sublattices with different values of magnetic moments, or material having different temperature dependencies of magnetization. See e.g., Kageyama et al., Weak Ferrimagnetism, Compensation Point, and Magnetization Reversal in Ni(HCOO)2.2H2O, Physical Rev. B, 224422 (2003). In an embodiment, the plurality of x-ray shielding particles comprises one or more paramagnetic materials. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one material that absorbs x-rays at one or more frequencies and fluoresce x-rays at one or more lower frequencies. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of boron, molybdenum, neodymium, niobium, strontium, tungsten yttrium, or zirconium, or combinations thereof. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of barium sulfate (BaSO4), boron nitride (BN), boron carbide (B4C), boron oxide (B2O3), or barium oxide (BaO). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of strontium oxide (SrO), zinc oxide (ZnO), or zirconium dioxide (ZrO2). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes one or more SiO2—PbO-alkali metal oxide glasses, CaO—SrO—B2O3 glasses, or boron-lithium glasses. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes borated high density polyethylene. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of mylar (C10H8O4), parylene-C(C8H7Cl), parylene-N(C8H8), poly(methyl methacrylate) (PMMA), polycarbonate (C16H14O3), polyethylene, or ultra high molecular weight polyethylene. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes silicon nitride (Si3N4). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of mercury (Hg), lead (Pb), lithium fluoride (LiF), tantalum (Ta), or tungsten (W). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes teflon (C2F4). In an embodiment, the carrier fluid ranges from about 1 to about 98 volume percent of the total volume of the x-ray shielding fluid composition. In an embodiment, an x-ray shielding fluid composition includes a carrier fluid including a fluid material having one or more x-ray absorption edges. In an embodiment, the carrier fluid includes a fluid material having one or more x-ray absorption edges different from the second x-ray shielding agent and the first x-ray shielding agent. In an embodiment, the carrier fluid includes a fluid material having one or more x-ray absorption edges different from the second x-ray shielding agent and the first x-ray shielding agent. In an embodiment, the carrier fluid includes a fluid that is substantially non-volatile, non-polar, or non-aqueous. In an embodiment, the carrier fluid includes mineral oil, paraffin oil, cycloparaffin oil, or synthetic hydrocarbon oil. In an embodiment, the carrier fluid includes a gas carrier. In an embodiment, the carrier fluid includes an aerosol. In an embodiment, the carrier fluid includes two or more immiscible liquids. In an embodiment, an x-ray shielding fluid composition includes one or more anti-flocculant agents. In an embodiment, the anti-flocculant agents adsorb onto the x-ray shielding particle surface, increasing the x-ray shielding particle electrostatic repulsion. The increased electrostatic repulsion of like charged x-ray shielding particles decreases the occurrence of x-ray shielding particle aggregates. In an embodiment the addition of anti-flocculant agents enhanced stability of the x-ray shielding fluid composition. In an embodiment, at least some of the plurality of x-ray shielding particles are coated with an anti-flocculant coating. In an embodiment, the x-ray shielding fluid composition includes at least a first x-ray shielding agent and a second x-ray shielding agent, the second x-ray shielding agent having one or more absorption edges different from the first x-ray shielding agent, and a carrier fluid. In an embodiment, the second x-ray shielding agent includes one or more characteristic x-ray absorption edges different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes one or more k-edges, or one or more l-edges, different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes an x-ray mass attenuation coefficient different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes at least one k-edge having an energy level lower than at least one k-edge of the first x-ray shielding agent. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of lead (Pb), lithium fluoride (LiF), tantalum (Ta), or tungsten (W). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes teflon (C2F4). In an embodiment, the x-ray shielding fluid composition includes a third x-ray shielding agent, the third x-ray shielding agent having one or more absorption edges different from the second x-ray shielding agent and the first x-ray shielding agent. In an embodiment, the x-ray shielding fluid composition includes a fourth x-ray shielding agent, the fourth x-ray shielding agent having one or more absorption edges different from the third x-ray shielding, the second x-ray shielding agent, and the first x-ray shielding agent. In an embodiment, the x-ray shielding fluid composition includes a fifth x-ray shielding agent, the fifth x-ray shielding agent having one or more absorption edges different from the fourth x-ray shielding agent, the third x-ray shielding, the second x-ray shielding agent, and the first x-ray shielding agent. FIGS. 1 through 4 show a dynamic x-ray shielding system 100 including one or more dynamic x-ray shielding devices 102, in which one or more methodologies or technologies can be implemented such as, for example, providing x-ray shielding, x-ray radiation protection, or the like. In an embodiment, the dynamic x-ray shielding device 102 forms part of a dynamic x-ray shielding garment 104. In an embodiment, the x-ray shielding system 100 includes one or more dynamic x-ray shielding devices 102 having at least a flexible layer 106 including a support structure 108 having a plurality of interconnected interstitial spaces 110 that provide a circulation network for an x-ray shielding fluid composition. In an embodiment, the dynamic x-ray shielding system 100 includes one or more x-ray shielding fluid reservoir assemblies 112 including one or more reservoirs 114 configured to store and supply an x-ray shielding fluid composition to or from the x-ray shielding agent reservoir 114, and along one or more of the plurality of interconnected interstitial space 110. In an embodiment, the dynamic x-ray shielding system 100 includes one or more pump assemblies 116 including one or more pumps 117 (e.g., mechanical pumps, magnetic pumps, centrifugal pumps, diaphragm pumps, gear pumps, flexible impeller pumps, peristaltic pumps, piston pumps, rotary valve pumps, etc.) that circulates the x-ray shielding fluid composition within at least a portion of the circulation network. For example, in an embodiment, the dynamic x-ray shielding system 100 includes an x-ray shielding fluid composition pump assembly 116 that is in fluid communication with at least one of the x-ray shielding fluid reservoir assembly 112 or the circulation network and that supplies and circulates the x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly 112, and along one or more regions within the circulation network. In an embodiment, the dynamic x-ray shielding garment 104 includes one or more pumps 117 that configured to generate magnetic forces on magnetic components of the x-ray shielding fluid composition to circulate the x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly 112, and along one or more regions within the circulation network In an embodiment, the dynamic x-ray shielding devices 102 includes one or more pumps 117 that circulate the x-ray shielding fluid composition within at least a portion of the circulation network. In an embodiment, the dynamic x-ray shielding system 100 includes one or more flow valve assemblies 118, including one or more flow valves 119, that are selectively actuatable between an open state which permits fluid flow through the one or more valve assemblies 118 such that the x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly 112 along at least a portion of a flow path, and a restrict state which restricts fluid flow through the assembly 118. In an embodiment, the dynamic x-ray shielding system 100 includes one or more flow valves 119 to selectively direct flow of the x-ray shielding fluid composition to or from the x-ray shielding agent reservoir 114. In an embodiment, the dynamic x-ray shielding system 100 includes one or more flow valves 119 to selectively direct flow of the x-ray shielding fluid composition within the circulation network. In an embodiment, dynamic x-ray shielding devices 102 includes support structure 108 configured to constrain the x-ray shielding fluid composition to move along one or more of the plurality of interconnected interstitial spaces 110. In an embodiment, the support structure 108 defines one or more tubular structures (e.g., as shown in FIG. 5) forming part of the plurality of interconnected interstitial spaces 110 that provide the circulation network for the x-ray shielding fluid composition. In an embodiment, the support structure 108 comprises one or more x-ray shielding agents. In an embodiment, the support structure 108 comprises one or more x-ray radio-opaque materials. In an embodiment, the support structure 108 comprises one or more x-ray attenuating materials. In an embodiment, the support structure 108 comprises one or more x-ray attenuating ceramic materials. Referring to FIG. 3, in an embodiment, the dynamic x-ray shielding device 102 includes at least a first layer 202 including one on more flow paths in fluid communication with the x-ray shielding fluid reservoir assembly 112 and configured to receive a first x-ray shielding fluid composition. Flow paths can take a variety of shapes, configurations, and geometric forms including regular or irregular forms and can have a cross-section of substantially any shape including, among others, circular, triangular, square, rectangular, polygonal, regular or irregular shapes, or the like, as well as other symmetrical and asymmetrical shapes, or combinations thereof. In an embodiment, the flow paths includes one or more interstitial spaces configured to receive the x-ray shielding fluid composition, and to provide the circulation network for the x-ray shielding fluid composition. In an embodiment, the first flow path includes a first flow valve assembly 108a selectively actuatable between an open state which permits fluid flow through the first flow valve assembly 108a such that the first x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly 112 along at least a portion of the first flow path, and a restrict state which restricts fluid flow through the first flow valve assembly 108a and along the first flow path. In an embodiment, the dynamic x-ray shielding device 102 includes a second layer 206 including a second flow path in fluid communication with the x-ray shielding fluid reservoir assembly 112 and configured to receive the second x-ray shielding fluid composition, the second flow path including a second flow valve assembly 118b selectively actuatable between an open state which permits fluid flow through the second flow valve assembly 118b such that the second x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly 112 along at least a portion of the first flow path, and a restrict state which restricts fluid flow through the second flow valve assembly 118b. In an embodiment, the dynamic x-ray shielding device 102 includes a third layer 210 including a third flow path in fluid communication with the x-ray shielding fluid reservoir assembly 112 and configured to receive the third x-ray shielding fluid composition, the third flow path including a third flow valve assembly selectively actuatable between an open state which permits fluid flow through the third flow valve assembly such that the third x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly 112 along at least a portion of the first flow path, and a restrict state which restricts fluid flow through the third flow valve assembly. In an embodiment, at least one of the first flow path or the second flow path includes one or more tubular structures. In an embodiment, at least one of the first flow path or the second flow path includes one or more recirculation tubular structures in fluid communication with the x-ray shielding fluid reservoir assembly 112 and operable to distribute at least one of the first x-ray shielding fluid composition or the second x-ray shielding fluid composition through at least a portion of the first flow path or the second flow path. In an embodiment, at least one of the first layer 202 or the second layer 206 comprises one or more x-ray shielding agents. In an embodiment, at least one of the first layer 202 or the second layer 206 comprises one or more x-ray radio-opaque materials. In an embodiment, at least one of the first layer 202 or the second layer 206 comprises one or more x-ray attenuating materials. In an embodiment, at least one of the first layer 202 or the second layer 206 comprises one or more x-ray attenuating ceramic materials. In an embodiment, the dynamic x-ray shielding system 100 includes one or more x-ray shielding fluid reservoirs 114 configured to store and supply at least a first x-ray shielding fluid composition and a second x-ray shielding fluid composition. In an embodiment, the dynamic x-ray shielding device 102 includes at least one x-ray shielding fluid reservoir assembly 112 including one or more x-ray shielding fluid reservoirs 114. In an embodiment, the x-ray shielding fluid reservoir assembly 112 is structured and arranged to hold the x-ray shielding fluid composition and to selectively enable fluid communication between one or more x-ray shielding fluid reservoirs and the plurality of interconnected interstitial spaces 110. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding fluid supply controller 120 that is operable to manage fluid flow of the x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly 112, and along one or more of the plurality of interconnected interstitial space 110. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include at least a first x-ray shielding fluid composition and a second x-ray shielding fluid composition. In an embodiment, the second x-ray shielding fluid composition comprises one or more x-ray shielding agents different from those of the first x-ray shielding fluid composition. In an embodiment, the second x-ray shielding fluid composition comprises one or more x-ray shielding agents having one or more absorption edges different from those of the first x-ray shielding fluid composition. In an embodiment, the second x-ray shielding fluid composition comprises one or more x-ray shielding agents having one or more characteristic x-ray absorption edges different from those of the first x-ray shielding fluid composition. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include at least a first x-ray shielding fluid composition and a second x-ray shielding fluid composition, the second x-ray shielding fluid composition comprises one or more x-ray shielding agents having one or more k-edges, or one or more l-edges, different from those of the first x-ray shielding fluid composition. In an embodiment, the second x-ray shielding fluid composition comprises one or more x-ray shielding agents having one or more x-ray mass attenuation coefficients different from those of the first x-ray shielding fluid composition. In an embodiment, the second x-ray shielding fluid composition comprises one or more x-ray shielding agents having at least one k-edge having an energy level lower than at least one k-edge of the first x-ray shielding fluid composition. In an embodiment, the second x-ray shielding fluid composition comprises one or more x-ray shielding agents different from those of the second x-ray shielding fluid composition and the first x-ray shielding fluid composition. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having a plurality of x-ray shielding particles, each including one or more x-ray shielding agents, and a carrier fluid. In an embodiment, the plurality of x-ray shielding particles includes one or more x-ray radio-opaque materials. In an embodiment, the plurality of x-ray shielding particles includes one or more x-ray attenuating materials. In an embodiment, the plurality of x-ray shielding particles includes one or more x-ray attenuating ceramic materials. In an embodiment, the plurality of x-ray shielding particles includes one or more x-ray absorbers. In an embodiment, the plurality of x-ray shielding particles include one or more x-ray scattering materials. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of boron, molybdenum, neodymium, niobium, strontium, tungsten yttrium, or zirconium, or combinations thereof. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of barium sulfate (BaSO4), boron nitride (BN), boron carbide (B4C), boron oxide (B2O3), or barium oxide (BaO). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of strontium oxide (SrO), zinc oxide (ZnO), or zirconium dioxide (ZrO2). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes one or more SiO2—PbO-alkali metal oxide glasses, CaO—SrO—B2O3 glasses, or boron-lithium glasses. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes borated high density polyethylene. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of mylar (C10H8O4), parylene-C(C8H7Cl), parylene-N(C8H8), poly(methyl methacrylate) (PMMA), polycarbonate (C16H14O3), polyethylene, or ultra high molecular weight polyethylene. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes silicon nitride (Si3N4). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of lead (Pb), lithium fluoride (LiF), tantalum (Ta), or tungsten (W). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes teflon (C2F4). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes lead (II) oxide (PbO). In an embodiment, the carrier fluid comprises about 1 to about 98 volume percent of the total volume of the x-ray shielding fluid composition. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having a plurality of x-ray shielding particles, each having at least a first x-ray shielding agent and a second x-ray shielding agent, the second x-ray shielding agent having one or more absorption edges different from the first x-ray shielding agent, and a carrier fluid. In an embodiment, the second x-ray shielding agent includes one or more characteristic x-ray absorption edges different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes one or more k-edges, or one or more l-edges, different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes an x-ray mass attenuation coefficient different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes at least one k-edge having an energy level lower than at least one k-edge of the first x-ray shielding agent. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having a plurality of x-ray shielding particles having at least a third x-ray shielding agent, the third x-ray shielding agent having one or more absorption edges different from the second x-ray shielding agent and the first x-ray shielding agent. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having a plurality of x-ray shielding particles having at least a fourth x-ray shielding agent, the fourth x-ray shielding agent having one or more absorption edges different from the third x-ray shielding agent, the second x-ray shielding agent, and the first x-ray shielding agent. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having a plurality of x-ray shielding particles having at least a fifth x-ray shielding agent, the fifth x-ray shielding agent having one or more absorption edges different from the fourth x-ray shielding agent, the third x-ray shielding agent, the second x-ray shielding agent, and the first x-ray shielding agent. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having at least a first x-ray shielding agent and a second x-ray shielding agent, the second x-ray shielding agent having one or more absorption edges different from the first x-ray shielding agent, and a carrier fluid. In an embodiment, the second x-ray shielding agent includes one or more characteristic x-ray absorption edges different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes one or more k-edges, or one or more l-edges, different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes an x-ray mass attenuation coefficient different from the first x-ray shielding agent. In an embodiment, the second x-ray shielding agent includes at least one k-edge having an energy level lower than at least one k-edge of the first x-ray shielding agent. In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes at least one of mercury (Hg), lead (Pb), lithium fluoride (LiF), tantalum (Ta), or tungsten (W). In an embodiment, at least one of the first x-ray shielding agent or the second x-ray shielding agent includes teflon (C2F4). In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having a third x-ray shielding agent, the third x-ray shielding agent having one or more absorption edges different from the second x-ray shielding agent and the first x-ray shielding agent. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having a fourth x-ray shielding agent, the fourth x-ray shielding agent having one or more absorption edges different from the third x-ray shielding, the second x-ray shielding agent, and the first x-ray shielding agent. In an embodiment, the one or more x-ray shielding fluid reservoirs 114 include an x-ray shielding fluid composition having a fifth x-ray shielding agent, the fifth x-ray shielding agent having one or more absorption edges different from the fourth x-ray shielding agent, the third x-ray shielding, the second x-ray shielding agent, and the first x-ray shielding agent. In an embodiment, the dynamic x-ray shielding system 100 includes an x-ray shielding fluid supply controller 120 associated with one or more flow valve assemblies 116 and configured to selectively actuate the one or more flow valve assemblies 118 to regulate fluid flow of a defined quantity of x-ray shielding fluid composition from one or more reservoirs 114, through the one or more flow valve assemblies 118, into the at least a portion of the circulation network. For example, in an embodiment, the dynamic x-ray shielding system 100 includes an x-ray shielding fluid supply controller 120 associated with at least the first flow valve assembly 108a and the second flow valve assembly 118b and configured to selectively actuate the first or the second flow valve assembly 118b to regulate fluid flow of a defined quantity of at least one of the first x-ray shielding fluid composition or the second x-ray shielding fluid composition from the reservoir, through at least one of the first flow valve or the second flow valve, into the at least a portion of the first flow path or the second flow path. In an embodiment, the x-ray shielding fluid supply controller 120 includes, among other things, one or more computing devices 122 such as a processor (e.g., a microprocessor), a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or the like, or any combinations thereof. For example, in an embodiment, the x-ray shielding fluid supply controller 120 includes one or more computing devices 122 operably couple to at least one of an x-ray shielding fluid composition pump assembly 116 or a flow valve assembly 118 and configured to actuate at least one of the x-ray shielding fluid composition pump assembly 116 or the flow valve assembly 118. In an embodiment, the x-ray shielding fluid supply controller 120 includes one or more computing devices 122 operably couple to at least one flow valve assembly 118 and is configured to actuate the flow valve assembly 118 between an open state which permits fluid flow through the flow valve assembly 118 such that an x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly 112 along at least a portion of a flow path, and a restrict state which restricts fluid flow through the flow valve assembly 118. In an embodiment, the x-ray shielding fluid supply controller 120 includes discrete digital or analog circuit elements or electronics, or combinations thereof. In an embodiment, the x-ray shielding fluid supply controller 120 includes one or more ASICs having a plurality of predefined logic components. In an embodiment, the x-ray shielding fluid supply controller 120 includes one or more FPGA having a plurality of programmable logic components. In an embodiment, the x-ray shielding fluid supply controller 120 includes one or more components operably coupled (e.g., communicatively, electromagnetically, magnetically, ultrasonically, optically, inductively, electrically, capacitively coupled, or the like) to each other. In an embodiment, the x-ray shielding fluid supply controller 120 includes one or more remotely located components. In an embodiment, remotely located components are operably coupled via wireless communication. In an embodiment, remotely located components are operably coupled via one or more receivers 182, transceivers 184, or transmitters 186, or the like. In an embodiment, the x-ray shielding fluid supply controller 120 includes one or more memory devices 124 that, for example, store flow control instructions or data. Non-limiting examples of one or more memory devices 124 include volatile memory (e.g., Random Access Memory (RAM), Dynamic Random Access Memory (DRAM), or the like), non-volatile memory (e.g., Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Compact Disc Read-Only Memory (CD-ROM), or the like), persistent memory, or the like. Further non-limiting examples of one or more memory devices 124 include Erasable Programmable Read-Only Memory (EPROM), flash memory, or the like. The one or more memory devices 124 can be coupled to, for example, one or more computing devices 122 by one or more instructions, data, or power buses. In an embodiment, the x-ray shielding fluid supply controller 120 includes one or more computer-readable media drives, interface sockets, Universal Serial Bus (USB) ports, memory card slots, or the like, and one or more input/output components such as, for example, a graphical user interface, a display, a keyboard, a keypad, a trackball, a joystick, a touch-screen, a mouse, a switch, a dial, or the like, and any other peripheral device. In an embodiment, the x-ray shielding fluid supply controller 120 includes one or more user input/output components that are operably coupled to at least one computing device 122 to control (electrical, electromechanical, software-implemented, firmware-implemented, or other control, or combinations thereof) at least one parameter associated with, for example, determining an exposure status of a user in response to one or more transcutaneously received x-ray radiation stimuli obtained via the implantable radiation sensing device 102. In an embodiment, the x-ray shielding fluid supply controller 120 includes a computer-readable media drive or memory slot configured to accept signal-bearing medium (e.g., computer-readable memory media, computer-readable recording media, or the like). In an embodiment, a program for causing a system to execute any of the disclosed methods can be stored on, for example, a computer-readable recording medium (CRMM), a signal-bearing medium, or the like. Non-limiting examples of signal-bearing media include a recordable type medium such as a magnetic tape, floppy disk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk (DVD), Blu-Ray Disc, a digital tape, a computer memory, or the like, as well as transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, etc.), a wired communications link, a wireless communication link (e.g., receiver 182, transceiver 184, transmitter 186, transmission logic, reception logic, etc.). Further non-limiting examples of signal-bearing media include, but are not limited to, DVD-ROM, DVD-RAM, DVD+RW, DVD-RW, DVD-R, DVD+R, CD-ROM, Super Audio CD, CD-R, CD+R, CD+RW, CD-RW, Video Compact Discs, Super Video Discs, flash memory, magnetic tape, magneto-optic disk, MINIDISC, non-volatile memory card, EEPROM, optical disk, optical storage, RAM, ROM, system memory, web server, or the like. In an embodiment, the x-ray shielding fluid supply controller 120 includes circuitry having one or more modules optionally operable for communication with one or more input/output components that are configured to relay user output and/or input. In an embodiment, a module includes one or more instances of electrical, electromechanical, software-implemented, firmware-implemented, or other control devices. Such devices include one or more instances of memory 120, computing devices 122, antennas, power or other supplies, logic modules or other signaling modules, gauges or other such active or passive detection components, piezoelectric transducers, shape memory elements, micro-electro-mechanical system (MEMS) elements, or other actuators. In an embodiment, the dynamic x-ray shielding system 100 includes an x-ray shielding fluid supply controller 120 associated with at least the first flow valve assembly 108a and the second flow valve assembly 118b and configured to selectively actuate the first or the second flow valve assembly 118b to regulate fluid flow of a defined quantity of at least one of the first x-ray shielding fluid composition or the second x-ray shielding fluid composition from the reservoir, through at least one of the first flow valve or the second flow valve, into the at least a portion of the first flow path or the second flow path. In an embodiment, the x-ray shielding fluid supply controller 120 is operable to actuate fluid flow of the first x-ray shielding fluid composition or the second x-ray shielding fluid, received in the x-ray shielding fluid reservoir assembly 112, to or from the x-ray shielding agent reservoir and along respectively one of the first flow path or the second flow path. In an embodiment, the x-ray shielding fluid supply controller 120 is operable to actuate concurrent or sequential fluid flow of the first x-ray shielding fluid composition or the second x-ray shielding fluid, received in the x-ray shielding fluid reservoir assembly 112, to or from the x-ray shielding agent reservoir and along respectively one of the first flow path or the second flow path. In an embodiment, then x-ray shielding fluid supply controller 120 includes control logic 149 arranged to determine an actuate flow condition and to actuate the flow of the first x-ray shielding fluid composition or the second x-ray shielding fluid, received in the x-ray shielding fluid reservoir assembly 112; to or from the x-ray shielding agent reservoir and along respectively one of the first flow path or the second flow path, responsive to the actuate flow condition. In an embodiment, then x-ray shielding fluid supply controller 120 includes control logic 149 arranged to determine an actuate flow condition and to actuate the flow of the first x-ray shielding fluid composition or the second x-ray shielding fluid, received in the x-ray shielding fluid reservoir assembly 112, to or from the x-ray shielding agent reservoir and along respectively one of the first flow path or the second flow path, responsive to at least one of an authorization protocol, an authentication protocol, or an activation protocol. In an embodiment, the x-ray shielding fluid supply controller 120 includes a speech recognition module 123 that causes the x-ray shielding fluid supply controller 120 to modulate the flow of the first x-ray shielding fluid composition or the second x-ray shielding fluid, received in the x-ray shielding fluid reservoir assembly 112, to or from the x-ray shielding agent reservoir 114 and along respective one of the first flow path or the second flow path 210, responsive to one or more audio inputs. In an embodiment, the dynamic x-ray shielding system 100 includes a power source 150 including at least one of a thermoelectric generator 152, a piezoelectric generator 154, a microelectromechanical system generator 156, or a biomechanical-energy harvesting generator 158. In an embodiment, the dynamic x-ray shielding system 100 includes a power source 150 electromagnetically, magnetically, ultrasonically, optically, inductively, electrically, or capacitively coupled to the x-ray shielding fluid supply controller 120. In an embodiment, the dynamic x-ray shielding system 100 includes an energy transfer system 160 electromagnetically, magnetically, ultrasonically, optically, inductively, electrically, or capacitively coupled to the x-ray shielding fluid supply controller 120. In an embodiment, the dynamic x-ray shielding system 100 includes one or more x-ray radiation sensor devices 170. In an embodiment, the one or more x-radiation sensing devices 170 are operable to detect (e.g., assess, calculate, evaluate, determine, gauge, measure, monitor, quantify, resolve, sense, or the like) an incident x-ray radiation. In an embodiment, during operation, the x-ray radiation sensor devices 170 detects at least one of an actual or a potential exposure event and alerts the dynamic x-ray shielding devices 102, or the x-ray shielding fluid supply controller 120, to check whether the dynamic x-ray shielding devices 102 is activated or functional to shield or protect the user. In an embodiment, during operation, the x-ray radiation sensor devices 170 detects at least one of an actual or a potential exposure event and alerts the dynamic x-ray shielding devices 102, or the x-ray shielding fluid supply controller 120, to activate the flow of the x-ray shielding fluid composition to or from the one or more x-ray shielding fluid reservoirs and along one or more of the plurality of interconnected interstitial spaces. In an embodiment, the dynamic x-ray shielding devices 102 includes one or more an x-ray radiation sensor devices 170 operably coupled to the x-ray shielding fluid supply controller 120. In an embodiment, the radiation sensing device 170 is operable to detect at least one characteristic (e.g., a fundamental characteristic, a spectral characteristic, a spectral signature, a physical quantity, an absorption coefficient, or the like) associated with an x-ray radiation exposure event. In an embodiment, the dynamic x-ray shielding device 102 includes one or more x-ray radiation sensor devices 170 disposed on a user-side of the first layer that acquire at least a portion of penetrating x-ray radiation stimulus and transduce the penetrating x-ray radiation stimulus acquired by the x-ray radiation sensor device 170 into at least one measurand indicative of an x-ray flux throughput during an integration period of the one or more x-ray radiation sensor devices 170. Non-limiting examples of x-ray radiation sensor devices 170 include scintillators 172 (e.g., inorganic scintillators, thallium doped cesium iodide scintillators, scintillator-photodiode pairs, scintillation detection devices, etc.), dosimeters 174 (e.g., x-ray dosimeters, thermoluminescent dosimeters, etc.), optically stimulated luminescence detectors, photodiode arrays, charge-coupled devices (CCDs) 176, complementary metal-oxide-semiconductor (CMOS) devices 178, or the like. In an embodiment, the x-ray radiation sensor device 170 includes one or more x-ray radiation fluoroscopic elements. In an embodiment, the x-ray radiation sensor device 170 includes one or more phosphorus doped elements (e.g., ZnCdS:Ag phosphorus doped elements). In an embodiment, the x-ray radiation sensor device includes one or more amorphous silicon thin-film transistor arrays. In an embodiment, the x-ray radiation sensor device includes one or more phosphors. In an embodiment, the x-ray radiation sensor device 170 includes one or more transducers 175 that detect and convert x-rays into electronic signals. For example, in an embodiment, the x-ray radiation sensor device 170 includes one or more x-ray radiation scintillation crystals. In an embodiment, the x-ray radiation sensor device 170 includes one or more thallium doped cesium iodide crystals (e.g., cesium iodide crystals doped with thallium CsI(Tl)). In an embodiment, during operation, the x-ray radiation sensor device's 170 computing device 122 processes the electronic signals generated by the one or more transducers 175 to determine one or more of intensity, energy, time of exposure, date of exposure, exposure duration, rate of energy deposition, depth of energy deposition, or the like associated with each x-ray detected. In an embodiment, during operation, incident x-ray radiation interacts with one or more detector crystalline materials (e.g., cadmium zinc telluride, etc.) within the x-ray radiation sensor device 170, which results in the generation of a current indicative of, for example, the energy of the incident x-ray radiation. In an embodiment, the radiation sensing device 170 includes circuitry 173 configured to, for example, detect x-ray radiation, determine exposure information based on one or more measurands, or the like. For example, in an embodiment, the x-ray radiation sensor device 170 includes at least one computing device 122 operably coupled to one or more sensors 171 that measure at least one of intensity data, energy, exposure time, rate of energy deposition, or depth of energy deposition associated with an x-ray radiation stimulus. In an embodiment, the x-ray radiation sensor device 170 includes at least one of a photodiode array, a scintillator, a thermoluminescent dosimeter, an x-ray radiation fluoroscopic element, or an amorphous silicon thin-film transistor array (e.g., amorphous silicon, thin-film transistor, active matrix array, etc.) operably coupled to at least one computing device 122. In an embodiment, at least one of the x-ray radiation sensor devices 170 is configured to detect an x-ray radiation stimulus associated with an x-ray radiation-emitting system 146 (e.g., a medical systems, a cabinet x-ray system, closed x-ray systems, x-ray inspection systems, x-ray screening systems, x-ray security systems, baggage x-ray systems, etc.) and to generate at least one measurand indicative of an x-ray radiation exposure event during an integration period of the x-ray radiation sensor device 170. For example, during operation, in an embodiment, the x-ray radiation sensor devices 170 associated with a dynamic x-ray shielding device 102 alerts the dynamic x-ray shielding device 102 of the actual or prospective x-ray exposure event. In response, in an embodiment, a dynamic x-ray shielding device 102 (via one or more x-ray shielding fluid supply controller 120) activates the flow of an x-ray shielding fluid composition to one or more region of dynamic x-ray shielding device 102 to provide x-ray shielding and protection. In an embodiment, the x-ray radiation sensor device 170 includes one or more pixels that acquire at least a portion of an x-ray radiation, stimulus and transduces the x-ray radiation stimulus acquired by the x-ray radiation sensor device 170 into at least one measurand indicative of an x-ray radiation exposure during an integration period of the x-ray radiation sensor device 170. In an embodiment, the x-ray radiation sensor device 170 includes at least one charge-coupled device 176, complementary metal-oxide-semiconductor device 178, or a scintillation detection device. In an embodiment, the x-ray radiation sensor device 170 includes at least one of a photodiode array, a scintillator 172, a thermoluminescent dosimeter, an x-ray radiation fluoroscopic element, or an amorphous silicon thin-film transistor array. In an embodiment, the x-ray radiation sensor device 170 includes at least one computing device 122 operably coupled to one or more sensors 171 configured to acquire at least one of intensity data, x-ray energy, exposure time, rate of energy deposition, or depth of energy deposition associated with the x-ray radiation stimulus. In an embodiment, the dynamic x-ray shielding system 100 includes an x-ray radiation sensor device 170 operable to detect at least one x-ray radiation exposure event. In an embodiment, the dynamic x-ray shielding system 100 an x-ray radiation sensor device 170 operable to determine an x-ray shielding status of the dynamic x-ray shielding device 102 by detecting the presence or absence of x-ray shielding fluid composition within one or more regions of the dynamic x-ray shielding device 102. In an embodiment, the x-ray shielding fluid supply controller 120 actuates at least one of a pump assembly 116 or a flow valve assembly 118 to actuate fluid flow of an x-ray shielding fluid composition, received in the one or more x-ray shielding fluid reservoirs 114, to or from the one or more x-ray shielding fluid reservoirs 114 and along one or more of the plurality of interconnected interstitial spaces 110 responsive to an output from the x-ray radiation sensor device 170 indicative of the x-ray radiation exposure event, a lack of x-ray shielding fluid composition in a region of the dynamic x-ray shielding device 102, the incorrect shield agent, or the like. FIG. 5 shows a dynamic x-ray shielding garment 104 in which one or more methodologies or technologies can be implemented such as, for example, detecting an x-ray radiation stimulus, providing x-ray shielding, providing x-ray radiation protection, or the like. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding fluid reservoir assembly 112 including a plurality of reservoirs 114 configured to store and supply at least a first x-ray shielding fluid composition and a second x-ray shielding fluid composition. In an embodiment, a dynamic x-ray shielding garment 104 includes at least a first layer 202 including a first flow path in fluid communication with the x-ray shielding fluid reservoir assembly 112 and configured to receive the first x-ray shielding fluid composition. In an embodiment, the first flow path includes first flow valve assembly 118a selectively actuatable between an open state which permits fluid flow through the first flow valve assembly 118a such that the first x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly along at least a portion of the first flow path, and a restrict state which restricts fluid flow through the first flow valve assembly 118a. In an embodiment, the first layer 202 includes an x-ray source side and a user protection side, and wherein the x-ray radiation sensor device 170 is located on the x-ray source of the first layer 202 so as to determine an incident x-ray flux. In an embodiment, the first layer 202 includes an x-ray source side and a user protection side. In an embodiment, the x-ray radiation sensor device 170 is located on the user protection side so as to determine an x-ray flux through the dynamic x-ray shielding garment 104. In an embodiment, a dynamic x-ray shielding garment 104 includes a second layer 206 including a second flow path in fluid communication with the x-ray shielding fluid reservoir assembly 112 and configured to receive the second x-ray shielding fluid composition, the second flow path including a second flow valve assembly 118b selectively actuatable between an open state which permits fluid flow through the second flow valve assembly 118b such that the second x-ray shielding fluid composition flows from the x-ray shielding fluid reservoir assembly 112 along at least a portion of the first flow path, and a restrict state which restricts fluid flow through the second flow valve assembly 118b. In an embodiment, a dynamic x-ray shielding garment 104 includes one or more x-ray radiation sensor devices 170 disposed on an x-ray source-side of the first layer 202 that acquire at least a portion of an incident x-ray radiation stimulus and transduce the incident x-ray radiation stimulus acquired by the x-ray radiation sensor device 170 into at least one measurand indicative of an incident x-ray flux during an integration period of the one or more x-ray radiation sensor devices 170. In an embodiment, a dynamic x-ray shielding garment 104 includes one or more x-ray radiation sensor devices 170 disposed on an x-ray source-side of the first layer 202 that detect an incident x-ray stimulus, and one or more x-ray radiation sensor devices 170 disposed on user-side of the first layer 202 that detect a transmitted x-ray stimulus. In an embodiment, a dynamic x-ray shielding garment 104 includes at least one computing device 122 that generates one or more parameters associated with a comparison between an incident x-ray stimulus and a transmitted x-ray stimulus. In an embodiment, the dynamic x-ray shielding garment 104 includes one or more sensors 171 to determine a presence of the x-ray shielding fluid composition within one or more sites within the circulation network. In an embodiment, the dynamic x-ray shielding garment 104 includes one or more sensors 171 to determine a presence of the x-ray shielding fluid composition within one or more locations within the dynamic x-ray shielding garment. In an embodiment, the dynamic x-ray shielding garment 104 includes one or more sensors 171 to determine a presence of the x-ray shielding fluid composition within one or more of the plurality of interconnected interstitial spaces 110. In an embodiment, a dynamic x-ray shielding garment 104 includes an x-ray shielding fluid supply controller 120 includes control logic 149 arranged to determine an actuate flow condition and to actuate the flow of the x-ray shielding fluid composition to or from the x-ray shielding fluid reservoir assembly 112, and along one or more of the plurality of interconnected interstitial spaces 110, responsive to the actuate flow condition. In an embodiment, the x-ray shielding fluid supply controller 120 actuates the flow of the x-ray shielding fluid composition to or from the x-ray shielding fluid reservoir assembly 112, and along one or more of the plurality of interconnected interstitial spaces 110, responsive to at least one of an authorization protocol, an authentication protocol, or an activation protocol. In an embodiment, the x-ray shielding fluid supply controller 120 includes a speech recognition module 123 that causes the x-ray shielding fluid supply controller 120 to modulate the flow of the x-ray shielding fluid composition to or from the x-ray shielding fluid reservoir assembly 112, and along one or more of the plurality of interconnected interstitial spaces 110, responsive to one or more audio inputs. In an embodiment, during operation, the x-ray shielding fluid supply controller 120 receives an input from the speech recognition module 123 associated with a verbal command to actuate flow to the x-ray shielding fluid composition. Responsive to the input from the speech recognition module 123, the x-ray shielding fluid supply controller 120 actuates at least one pump assembly 116 or flow valve assembly 118 to initiate the supply of x-ray shielding fluid composition to or from the x-ray shielding fluid reservoir assembly 112, and along a circulation network within the dynamic x-ray shielding device 102. In an embodiment, the dynamic x-ray shielding garment 104 includes a power source 150 including at least one battery. In an embodiment, the dynamic x-ray shielding garment 104 includes a power source 150 wired, or wireless coupled, to an external source. In an embodiment, the dynamic x-ray shielding garment 104 includes a power source 150 including at least one of a thermoelectric generator, a piezoelectric generator, a microelectromechanical system generator, or a biomechanical-energy harvesting generator. In an embodiment, the dynamic x-ray shielding garment 104 includes a power source 150 electromagnetically, magnetically, ultrasonically, optically, inductively, electrically, or capacitively coupled to the x-ray shielding fluid supply controller 120. In an embodiment, the dynamic x-ray shielding garment 104 includes an energy transfer system 160 electromagnetically, magnetically, ultrasonically, optically, inductively, electrically, or capacitively coupled to the x-ray shielding fluid supply controller 120. In an embodiment, the dynamic x-ray shielding garment 104 includes a pump assembly 116 including one or more pumps 117 that circulate the x-ray shielding fluid composition within at least a portion of the circulation network (mechanical, magnetic, etc.) For example, in an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding fluid composition pump assembly 116 that is in fluid communication with at least one of the x-ray shielding fluid reservoir assembly 112 or the circulation network that supplies and circulates the x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly 112, and along one or more regions within the circulation network. In an embodiment, the dynamic x-ray shielding garment 104 includes one or more pumps 117 that employ magnetic forces on magnetic components of the x-ray shielding fluid composition to circulate the x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly 112, and along one or more regions within the circulation network. In an embodiment, the dynamic x-ray shielding garment 104 includes one or more valves 119 to selectively direct flow of the x-ray shielding fluid composition to or from the x-ray shielding agent reservoir 114. In an embodiment, the dynamic x-ray shielding garment 104 includes one or more valves 119 to selectively direct flow of the x-ray shielding fluid composition within the circulation network. In an embodiment, the dynamic x-ray shielding garment 104 includes at least a second x-ray shielding fluid reservoir assembly 112 including one or more x-ray shielding fluid reservoirs 114. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 including one or more receivers 182, transceivers 184, or transmitters 186 that generate an output indicative of at least one of an x-ray shielding fluid composition presence within one or more regions of the plurality of interconnected interstitial spaces. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 including one or more receivers 182, transceivers 184, or transmitters 186 that generate an output indicative of x-ray sensor value. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 including one or more receivers 182, transceivers 184, or transmitters 186 that generate an output indicative of an authorization to x-ray source to irradiate. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 including one or more receivers 182, transceivers 184, or transmitters 186 that generate an output indicative of authorization to x-ray source spectrum or intensity. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 including an irradiation authorization component 188 that generates one or more cryptographic keys that provide authorization to the external x-ray radiation-emitting system 146 to initiate x-ray radiation delivery. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 including an irradiation authorization component 188 that generates one or more cryptographic keys that provide authorization to the external x-ray radiation-emitting system 146 to initiate a spectrum-specific x-ray dose regimen. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 including an irradiation authorization component 188 that generates one or more cryptographic keys that provide authorization to the external x-ray radiation-emitting system 146 to initiate an intensity-specific x-ray dose regimen. In an embodiment, the dynamic x-ray shielding garment 104 includes fluid supply controller 120 having one or more computing devices 122, operably coupled to one or more pump assemblies 116 including one or more pumps 117, that manage fluid flow of an x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly 112, and along one or more of the plurality of interconnected interstitial spaces. In an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 that receives x-ray potential exposure event data associated with delivery of an x-ray radiation stimulus from an x-ray radiation-emitting system 146. In an embodiment, the x-ray shielding status reporter device 180 is operably coupled to one or more x-ray shielding fluid supply controllers 120 that direct fluid flow of an x-ray shielding fluid composition received in an x-ray shielding fluid reservoir assembly associated with a dynamic x-ray shielding garment, to or from the x-ray shielding agent reservoir, and along one or more of a plurality of interconnected interstitial spaces within the dynamic x-ray shielding garment 104, responsive to an output signal from the x-ray shielding status reporter device 180. In an embodiment, the dynamic x-ray shielding garment 104 includes fluid supply controller 120 is configured to manage fluid flow of a gravity-fed x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly 112, and along one or more of the plurality of interconnected interstitial spaces. In an embodiment, the dynamic x-ray shielding garment 104 includes fluid supply controller 120 is configured to manage fluid flow of a pressure-fed x-ray shielding fluid composition to or from the x-ray shielding agent reservoir assembly 112, and along one or more of the plurality of interconnected interstitial spaces. FIG. 5 shows a dynamic x-ray shielding method 500. At 510, the dynamic x-ray shielding method 500 includes receiving x-ray potential exposure event data associated with delivery of an x-ray radiation stimulus from an x-ray radiation-emitting system 146. For example, in an embodiment, the dynamic x-ray shielding garment 104 includes an x-ray shielding status reporter device 180 having one or more receivers 182, transceivers 184, or transmitters 186 that receiving x-ray potential exposure event data associated with delivery of an x-ray radiation stimulus from an x-ray radiation-emitting system 146. At 512, receiving the potential x-ray exposure event data includes initiating a data transmission transfer between a dynamic x-ray shielding device and an x-ray radiation-emitting system 146. At 514, receiving the potential x-ray exposure event data includes initiating a data transmission transfer between a dynamic x-ray shielding device and an x-ray radiation-emitting system 146 based on the identification of the x-ray radiation sensing device 170. At 516, receiving the potential x-ray exposure event data includes telemetrically receiving, via one or more receivers 182, transceivers 184, or transmitters 186, proposed dose data, time to exposure data, time to exposure data, or duration of exposure data. At 518, receiving the potential x-ray exposure event data includes wirelessly receiving at least one of radiation intensity data, radiation energy data, radiation exposure time data, rate of radiation energy deposition, depth of radiation energy deposition data, absorbed dose data, absorbed dose rate data, committed effective dose data, cumulative dose data, effective dose data, equivalent dose data, or exposure data associated with the potential x-ray exposure event. At 520, the dynamic x-ray shielding method 500 includes directing fluid flow of an x-ray shielding fluid composition received in an x-ray shielding fluid reservoir assembly 112 associated with a dynamic x-ray shielding garment, to or from the x-ray shielding agent reservoir, and along one or more of a plurality of interconnected interstitial spaces 110 within the dynamic x-ray shielding garment, responsive to the x-ray potential exposure event data. For example, in an embodiment, the dynamic x-ray shielding garment includes 104 an x-ray shielding fluid supply controller 120 that is operable to directing fluid flow of an x-ray shielding fluid composition received in the x-ray shielding fluid reservoir assembly 116 associated with the dynamic x-ray shielding garment 104, to or from the one or more x-ray shielding agent reservoirs 117, and along one or more of a plurality of interconnected interstitial spaces 110 within the dynamic x-ray shielding garment, responsive to the x-ray potential exposure event data. At 522, directing the fluid flow of the x-ray shielding fluid composition includes directing a flow sufficient of the x-ray shielding fluid composition to modulate at least one of a penetration depth, intensity, or energy associated with the x-ray radiation stimulus. At 524, directing the fluid flow of the x-ray shielding fluid composition includes directing a flow sufficient of the x-ray shielding fluid composition to cause at least a portion of the dynamic x-ray shielding garment to have an x-ray shielding lead equivalence of about 0.25 millimeters to about 0.5 millimeters. At 526, directing the fluid flow of the x-ray shielding fluid composition includes directing a flow sufficient of the x-ray shielding fluid composition to cause at least a portion of the dynamic x-ray shielding garment to have an x-ray shielding lead equivalence of greater than about 0.25 millimeters. FIG. 6 shows an x-ray shielding method 600. At 610, the x-ray shielding method 600 includes actuating fluid flow of an x-ray shielding fluid composition received in one or more x-ray shielding fluid reservoirs associated with a dynamic x-ray shielding garment, to or from the x-ray shielding agent reservoir, and along one or more of a plurality of interconnected interstitial spaces 110 within the dynamic x-ray shielding garment responsive to a determination that an x-ray radiation-emitting system 146 is in operation. At 620, the x-ray shielding method 600 includes actuating fluid flow of an x-ray shielding fluid composition received in one or more x-ray shielding fluid reservoirs associated with a dynamic x-ray shielding garment, to or from the x-ray shielding agent reservoir, and along one or more of a plurality of interconnected interstitial spaces 110 within the dynamic x-ray shielding garment responsive to an input associated with a potential delivery of an x-ray radiation stimulus from an x-ray radiation-emitting system 146. At 630, the x-ray shielding method 600 includes receiving x-ray potential exposure event data associated with delivery of an x-ray radiation stimulus from an x-ray radiation-emitting system 146. At 640, the x-ray shielding method 600 includes concurrent or sequential actuating fluid flow of a first x-ray shielding fluid composition or the second x-ray shielding fluid, received in an x-ray shielding fluid reservoir assembly 112, to or from the x-ray shielding agent reservoir and along respectively one of a first flow path 204 or a second flow path 210 of a dynamic x-ray shielding apparatus, responsive to potential exposure event data indicative of an x-ray potential exposure event. FIG. 7 shows a dynamic x-ray shielding method 700. At 710, the dynamic x-ray shielding method 700 includes determining an actuate flow condition. At 720, the dynamic x-ray shielding method 700 includes concurrent or sequential actuating fluid flow of a first x-ray shielding fluid composition or the second x-ray shielding fluid, received in a plurality of x-ray shielding fluid reservoirs, to or from the plurality of x-ray shielding fluid reservoirs and along respectively one of a first flow path 204 or a second flow path 210 of a dynamic x-ray shielding apparatus, responsive to the actuate flow condition. At least a portion of the devices and/or processes described herein can be integrated into a data processing system. A data processing system generally includes one or more of a system unit housing, a video display device, memory such as volatile or non-volatile memory, processors such as microprocessors or digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices (e.g., a touch pad, a touch screen, an antenna, etc.), and/or control systems including feedback loops and control motors (e.g., feedback for detecting position and/or velocity, control motors for moving and/or adjusting components and/or quantities). A data processing system can be implemented utilizing suitable commercially available components, such as those typically found in data computing/communication and/or network computing/communication systems. Those having skill in the art will recognize that the state of the art has progressed to the point where there is little distinction left between hardware and software implementations of aspects of systems; the use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software can become significant) a design choice representing cost vs. efficiency tradeoffs. Those having skill in the art will appreciate that there are various vehicles by which processes and/or systems and/or other technologies described herein can be effected (e.g., hardware, software, and/or firmware in one or more machines or articles of manufacture), and that the preferred vehicle will vary with the context in which the processes and/or systems and/or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and/or firmware vehicle; alternatively, if flexibility is paramount, the implementer may opt for a mainly software implementation that is implemented in one or more machines or articles of manufacture; or, yet again alternatively, the implementer may opt for some combination of hardware, software, and/or firmware in one or more machines or articles of manufacture. Hence, there are several possible vehicles by which the processes and/or devices and/or other technologies described herein may be effected, none of which is inherently superior to the other in that any vehicle to be utilized is a choice dependent upon the context in which the vehicle will be deployed and the specific concerns (e.g., speed, flexibility, or predictability) of the implementer, any of which may vary. Those skilled in the art will recognize that optical aspects of implementations will typically employ optically-oriented hardware, software, and or firmware in one or more machines or articles of manufacture. The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact, many other architectures can be implemented that achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled,” to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably coupleable,” to each other to achieve the desired functionality. Specific examples of operably coupleable include, but are not limited to, physically mateable and/or physically interacting components, and/or wirelessly interactable, and/or wirelessly interacting components, and/or logically interacting, and/or logically interactable components. In an embodiment, one or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Such terms (e.g., “configured to”) can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise. The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by the reader that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware in one or more machines or articles of manufacture, or virtually any combination thereof. Further, the use of “Start,” “End,” or “Stop” blocks in the block diagrams is not intended to indicate a limitation on the beginning or end of any functions in the diagram. Such flowcharts or diagrams may be incorporated into other flowcharts or diagrams where additional functions are performed before or after the functions shown in the diagrams of this application. In an embodiment, several portions of the subject matter described herein is implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), or other integrated formats. However, some aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, the mechanisms of the subject matter described herein are capable of being distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal-bearing medium used to actually carry out the distribution. Non-limiting examples of a signal-bearing medium include the following: a recordable type medium such as a floppy disk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk (DVD), a digital tape, a computer memory, etc., and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link (e.g., transmitter, receiver, transmission logic, reception logic, etc.), etc.). While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to the reader that, based upon the teachings herein, changes and modifications can be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of the subject matter described herein. In general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). Further, if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense of the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense of the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). Typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.” With respect to the appended claims, the operations recited therein generally may be performed in any order. Also, although various operational flows are presented in a sequence(s), it should be understood that the various operations may be performed in orders other than those that are illustrated, or may be performed concurrently. Examples of such alternate orderings includes overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise. While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
044938128	summary	BACKGROUND OF THE INVENTION The present invention relates generally to a nuclear reactor valve and more particularly to a breeder reactor blanket fuel assembly coolant system valve which increases coolant flow to the blanket fuel assembly to minimize long-term temperature increases caused by fission of fissile fuel created from fertile fuel through operation of the breeder reactor. Valves may be used for many applications in nuclear reactors. Currently an important use of valves is in the nuclear reactor coolant system. However, no self-actuating valves are presently used to control coolant flow to each of the many fuel assemblies which form the core of the reactor. The present state-of-the-art uses a fixed-size orifice in each fuel assembly to provide the entrance for coolant flow to the fuel rods contained therein, and use of a check valve to prevent reverse flow has been considered. In certain circumstances, varying the size of each fuel assembly coolant entrance orifice may be desirable. For example, in breeder reactors the blanket fuel assemblies experience a long-term increase in temperature due to fuel rod power increase caused by an increase in fissile fuel content. This is brought about by the breeder reactor's operation in converting the blanket fuel assemblies' fertile fuel into fissile fuel. The long-term temperature increase may be different for each fuel assembly. Blanket fuel assemblies are designed to operate within a certain temperature range. Higher temperatures will degrade the fuel assembly by shortening material life. Lower temperatures will degrade the reactor's performance by lowering its power for a given coolant flow. Thus, the inherent problem of breeder reactor blanket assemblies is that, with a fixed-size coolant entrance orifice, beginning-of-life temperatures are too low with acceptable end-of-life temperatures, or end-of-life temperatures are too high with acceptable beginning-of-life temperatures. A size-varying orifice valve could increase coolant flow to the blanket fuel assembly to keep long-term temperature increases to a minimum. Another example where a size-varying fuel assembly coolant entrance orifice may be desirable is in a fissile fuel assembly designed for long life, where the fuel rod power, and hence temperature, will decrease as more of the fissile fuel is depleted over the long-term operation of the nuclear reactor. Here a size-varying orifice valve could decrease coolant flow to minimize temperature decreases. Some ways of changing the size of the fuel assembly's coolant entrance orifice include shutting down the reactor to change the orifice unit with one of different size, or equipping the fuel assembly coolant entrance with an externally controlled valve. A mechanically or electrically actuated valve for each fuel assembly making up the nuclear reactor core would pose serious design and operation problems because of the hostile environment. Also, a self-contained temperature-actuated valve would follow the short-term temperature fluctuations of plant startup, power transients and plant shutdown, and pose time-lag and fail-safe problems. SUMMARY OF THE INVENTION It is an object of the invention to provide a nuclear radiation actuated valve. It is another object of the invention to provide a self-contained nuclear reactor coolant system valve to control coolant flow. It is an added object of the invention to provide a breeder reactor blanket fuel assembly coolant flow entrance valve to minimize long-term temperature increases due to increases in fissile fuel formed from fertile fuel through breeder reactor operation. Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. In one aspect thereof, the valve of the present invention is utilized in a nuclear reactor and is characterized by first and second members arranged in a manner to form an orifice for the passage of a fluid therethrough. The members are formed of materials, respectively, having different nuclear radiation swelling properties whereby exposure to nuclear radiation effects differential swelling and relative movement of said members to vary the size of said orifice. Several benefits and advantages are derived from the invention. The valve's nuclear radiation actuation feature provides a simple, reliable, and self-contained valve suitable for use in a nuclear reactor core. The invention may be used as the coolant inlet orifice for a fuel assembly where long-term temperature changes are to be minimized without responding to short-term temperature fluctuations. The nuclear radiation actuated valve allows a long-life core fissile fuel assembly not to significantly decrease temperature as fissile fuel is depleted. It also allows a breeder reactor blanket fertile fuel assembly not to drastically increase temperature as fertile fuel is converted into fissile fuel and hence not to degrade the useful material life of the fuel assembly or adjacent reactor vessel internals.
062748769	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning microscope using a particle beam. More specifically, the present invention relates to an optimum inspection apparatus using a particle beam for performing observation or inspection of a fine dimension and/or an appearance structure of a semiconductor device. 2. Description of the Related Art A known critical dimension evaluation apparatus using an electron beam as a particle beam acquiring a sample image based on secondary electrons by scanning an electron beam on a semiconductor sample and inspecting a dimension concerning the characteristic pattern for the sample is disclosed in Japanese Patent Application Number 60-161514. A known appearance inspection electron beam apparatus inspecting an abnormality of a sample by comparing an image of a scanning electron microscope with a standard pattern is disclosed in Japanese Patent Application Number 5-258703. A method introduced by these apparatus has high resolution for the image compared to an inspection method using an optical source and is very useful for inspecting a sub-micron semiconductor pattern. In the prior art apparatus, an optimum focus adjustment of an electron lens system is performed based upon signals from at least 3 sample images obtained by scanning the electron beam on the same sample under different conditions of focusing shift of the electron lens system. In order to reduce the time spent for focus adjustment, a focus adjustment means for detecting a height of a sample using a height sensor using light reflection (Z sensor) and adjusting the focus of an electron lens system based upon a table produced in advance to reduce the deviation of a height of a sample from the standard is indicated in a Japanese patent application number 8-273575. Since there are such problems that a sample surface measured by the Z sensor does not completely accord with an extreme surface of the sample and that has a disadvantage in a reappearance of the focus adjustment due to hysteresis of magnetization in the electron lens system, resolution of the sample image decreased without the focus adjustment using an electron beam scanning. A method for obtaining a high resolution for a sample image based upon mathematical conversion (integral conversion) of the sample image using a beam profile measured in advance is introduced in a Japanese patent application number 2-181639. However, this method does not consider variation of the beam profile due to variation of the focusing-shift for each spot from which the sample image is taken. SUMMARY OF THE INVENTION It is necessary for the above inspection apparatus to improve its throughput since a quantity for an inspection is increased by an improved resolution. However, in the prior art, time spent in adjusting a focus of the beam accompanied with the beam scanning resulting in an extreme deterioration of an inspection throughput was not taken into consideration. There is still a considerable problem that although it is necessary to execute pluralities of electron beam irradiation on a sample for performing a focus compensation, the irradiation causes contamination on the sample which varies the width of wiring circuit in the sample. Further, there is a problem that because excessive irradiation of the electron beam causes the sample to be electrified, the electron beam used to irradiate the sample is affected so that an acquired sample image causes distortion which deteriorates the accuracy of critical dimensional measurement. An object of the present invention is to provide an inspection apparatus using a particle beam having high resolution and high throughput. The above-mentioned object of the invention is achieved by performing a blur-separated image calculation in the inspection apparatus having a sample-image-obtaining means which scans the particle beam on a sample and a sample inspection means which uses the numerical operation of a sample image for an inspection. The inspection apparatus has a focusing-shift-detection means which derives the characteristic quantity of a focusing-shift from the sample image, a beam-blur-profile generation means which generates a beam-blur profile, corresponding to a blur of the particle beam, based upon the characteristic quantity of the focusing-shift and a blur-separation means which generates a blur-separated image based upon a separation or a reduction of a component of the beam-blur profile in the sample image. The focusing-shift-detection means according to the present invention detects a certain spatial frequency of a Fourier spectrum of the sample image as the characteristic quantity of the focusing-shift. Furthermore, there is provided means for memorizing by correlating the sample image, the beam-blur profile and the blur-separated image and means for displaying simultaneously a set of the sample image, the beam-blur profile and the blur-separated image. The invention also encompasses an inspection method using the inspection apparatus. The method involves moving a sample to an inspection point for the sample after an adjustment of an astigmatism for the particle beam is completed, acquiring at most two different kinds of sample images by scanning the particle beam for each inspection point of the sample and inspecting the sample based upon the sample images. The inspection apparatus of the present invention also includes means for producing a first display image acquired by scanning the particle beam on the sample, means for deriving the characteristic quantity of the focusing-shift based upon the first display image, means for producing a second display image based upon the characteristic quantity of the focusing-shift and the first display image and means for inspecting the sample based upon the second display image. These and other objects, features and advantages of the present invention will become more apparent in view of the following detailed description of the preferred embodiments.
052280691	claims	1. A computerized tomographic (CT) scanner comprising: a patient holding means, a gantry, means for mounting an X-ray source on said gantry on one side of said patient holding means, means for mounting a partial ring of discrete X-ray detectors on the other side of said patient holding means, holding a patient, mounting an X-ray source on one side of said patient, mounting an X-ray detector means on the other side of said patient, simultaneously rotating the X-ray source and said X-ray detector means about the patient more than 180.degree. per rotation in a rotate-rotate mode, and selectively detecting either X-rays that have simultaneously traversed two juxtaposed planar sections in said patient or X-rays that have traversed a single planar section in said patient. 2. The CT scanner of claim 1 wherein said partial ring of a second row of said two rows being juxtaposed to the first row in the Z direction with both the first row and the second row of detectors extending in the X direction and being defined by the limits of the fan beam. 3. The CT scanner of claim 1 wherein the partial ring of the the second row is angularly smaller than the limits of the fan beam. 4. The CT scanner of claim 1 including shielding means for preventing interaction between said juxtaposed rows of detectors said shielding means being in the order of no more than 0.1 mm thick. 5. A method of selectively obtaining computerized tomographic (CT) image data from either a single slice in the patient or from two contiguous slices in the patient, said method comprising the steps of: 6. The method of claim 5 including selectively shifting said detector means relative to said X-ray source in the Z direction; where X, Y and Z are directions in a Cartesian coordinate system with Y being the direction between the X-ray source and the detector means, Z being the longitudinal direction of the patient and with X being the direction of rotation and Z being normal to both the X and the Y directions. 7. The method of claim 6 including the step of shifting the detector means in the Z direction relative to the X-ray source so that only X-rays from the X-ray source that pass through only a single slice of the patient are detected. 8. The method of claim 6 including the step of shifting the detector means in the Z direction relative to the X-ray source so that X-rays from the X-ray source that pass through two contiguous slices are detected.
	description	The present disclosure is directed to a replaceable light source and, more particularly, to a replaceable light source for a field lamp projector and/or an optical distance indicator of a radiation generating device such as a linear accelerator for medical treatment applications. Linear accelerators are typically used to generate radiation for use in medical treatment. To assist with calibration, these devices typically include a field lamp projector and/or an optical distance indicator. Field lamp projectors project a pattern of light through an optical assembly and onto the patient. The pattern of light estimates the pattern of radiation that is to be projected. Optical distance indicators project a light through an optical assembly that includes a lens having a plurality of numbers etched or printed thereon. This results in the projection of one or more numbers on the patient, which indicates to the technician a distance between the radiation generator and the patient. The light sources for these field lamp projectors and optical distance indicators conventionally include halogen bulbs, which create a large sphere of light. To try and focus the light toward the optical assemblies and to reduce reflections in the projectors, apertured plates are often arranged between the bulbs and the optical assemblies. One aspect of the present disclosure provides a replacement light apparatus including a base plate, a grip plate, a bearing member, and a light source. The grip plate extends from a first surface of the base plate. The bearing member extends from a second surface of the base plate that is opposite the first surface. The bearing member includes a bearing surface disposed in a first plane that is perpendicular to a second plane, in which the base plate is disposed. The light source is mounted on the bearing surface of the bearing member and adapted to project a cone of light centered on an illumination axis that extends perpendicular to the bearing surface. Another aspect of the present disclosure provides a replacement light apparatus including a base plate, a grip plate, a bearing member, a light-emitting-diode, a power source, and a pair of light-emitting-diode drivers. The grip plate extends from a first surface of the base plate. The bearing member extends from a second surface of the base plate that is opposite the first surface. The bearing member includes a bearing surface disposed in a first plane that is perpendicular to a second plane, in which the base plate is disposed. The light-emitting-diode is mounted on the bearing surface of the bearing member and adapted to project a cone of light centered on an illumination axis that extends perpendicular to the bearing surface. The power sourced is connected to the light-emitting-diode. The pair of light-emitting-diode drivers connected in parallel between the light-emitting-diode and the power source. Yet another aspect of the present disclosure provides a radiation generating device including a linear particle accelerator, a collimator, and a light projector. The collimator is arranged in proximity to the linear particle accelerator for aligning the particles departing the accelerator and projecting a radiation field. The light projector includes a housing, an optical assembly, and a light fixture. The optical assembly is carried by the housing and has an optical axis. The light fixture is removably disposed in the housing and includes a bearing plate defining a bearing surface disposed in a first plane that is perpendicular to the optical axis. The light source is mounted on the bearing surface and centered on the optical axis. The light source is adapted to project a cone of light centered on an illumination axis that is coaxial with the optical axis. A still further aspect of the present disclosure includes a method of upgrading a radiation generating device. The method includes removing a cover from a collimator of the radiation generating device. Additionally, the method includes replacing an existing light fixture with an upgraded light fixture. Replacing the existing light fixture includes disconnecting the existing light fixture from a power source. And, removing the existing light fixture from a light fixture housing by sliding the existing light fixture out along a linear axis of a socket of the housing, in which the existing light fixture resides. And, connecting the upgraded light fixture to the power source. And, further, centering a light source of the upgraded light fixture on an optical axis of an optical assembly carried by the housing by sliding the upgraded light fixture into the socket of the housing along the linear axis, the optical axis being perpendicular to the linear axis of the socket. A still further aspect of the present disclosure includes a method of projecting a pattern of light on a target of a radiation generating device. The method includes emitting a cone of light to produce a pattern of light on the target, wherein the cone of light is emitted along an illumination axis with a light source, the light source being carried by a projector housing of the radiation generating device and the illumination axis being disposed coaxially with an optical axis of an optical assembly carried by the projector housing. The present disclosure is directed to replaceable light sources for radiation generating devices such as linear accelerators, radiation generating devices including such replaceable light sources, and related methods. The replaceable light sources of the disclosure include light-emitting-diodes (LEDs), as opposed to conventionally used halogen bulbs. As will be described, LEDs provide a more concentrated cone of light in the disclosed examples, which advantageously results in extended life expectancy and increased operational efficiency. FIG. 1 depicts one version of a radiation generating device 10 constructed in accordance with the principles of the present disclosure. The device 10 includes a stationary support structure 12, a gantry 14, and a bed 22. In the conventional manner, the gantry 14 contains a linear accelerator 16, a bending magnet 18, and a collimator 20 for generating a radiation field 24, as shown, to be projected on a patient 25 lying on the bed 22. In addition to the foregoing, the radiation generating device 10 of FIG. 1 includes a field lamp projector 26 and an optical distance indicator 28 carried within the collimator 20. The field lamp projector 26 is adapted to create a pattern of light on the patient 25 to estimate a pattern of radiation that falls on the patient 24 during operation of the radiation generating device 10. The optical distance indicator 28 projects a light defining one or more numbers on the patient 25, whereby the number(s) indicate a distance between the radiation generator 10 and the patient 25. Referring now to FIG. 2, the field lamp projector 26 of the present disclosure includes a projector housing 30 and a light fixture 32. The projector housing 30 defines a socket 34 and an optical cavity 36 that intersects the socket 34. The light fixture 32 is slidably and removably disposed in the socket 34. The optical cavity 36 contains an optical assembly 38. The optical assembly 38 can include one or more lenses 40 disposed along an optical axis Ao for focusing light emitted by the light fixture 32 onto the patient 25. As shown, the light fixture 32 of the presently disclosed version of the disclosure includes a base plate 42, a grip plate 44, a bearing member 46, and a light source 47. In some versions, the base plate 42, grip plate 44, and bearing member 46 can be constructed from a single piece of material such as aluminum, for example, which may be anodized to reduce glare and reflections. In other versions, the base plate 42, grip plate 44, and bearing member 46 can be constructed of different pieces assembled together by welding, brazing, adhesive, or any other suitable means. With continued reference to FIG. 2 and additionally to FIG. 3, the base plate 42 of the bearing member 46 can include a generally flat plate having a first surface 60 and a second surface 62 that is opposite the first surface 60. Similar to the base plate 48, the grip plate 44 also can include a generally flat plate and, in the disclosed version, extends perpendicularly from the first surface 60 of the base plate 42. The bearing member 46 extends from the second surface 62 of the base plate 42. In the disclosed version, the bearing member 46 includes a bearing plate 48 and a body portion 50. The bearing plate 48 can be a generally flat plate that defines a bearing surface 64 carrying the light source 47. In the disclosed version, the bearing surface 64 is flat and disposed in a first plane P1 that is perpendicular to a second plane P2, in which the base plate 42 resides. The body portion 50 can be a cylindrical form defining a through bore 52 that at least partially overlaps with an opening 54 in the base plate 42 for accommodating electrical connections 57 (shown in FIGS. 3 and 6) such as one or more wires for connecting the light source 47 to a power source 58 (shown in FIG. 6). The light source 47 of the presently disclosed version includes a light-emitting-diode (LED) 66 mounted on a circuit board 68. In the depicted version, the light source 47 is mounted flush on the bearing surface 64 of the bearing member 46 and centered on the optical axis Ao of the optical assembly 38. So configured, and as shown, the light source 47 is adapted to project a cone of light 70 that is disposed on an illumination axis Ai, which is coaxial with the optical axis Ao of the optical assembly 38. The illumination axis Ai therefore also extends perpendicular to the first plane P1 and the bearing surface 64 of the bearing member 46. So configured, the light source 47 advantageously directs and concentrates its cone of light 70 in the desired direction along the optical axis Ao, which thereby reduces reflections inside the socket 34 and optical cavity 36 and optimizes the efficiency of the device. In one version, the light source 47 of the present disclosure can include an LED having a color temperature of 5650 k, exhibiting 235 lumens when running at 700 mA, or 320 lumens when running at 1000 mA. LEDs having such characteristics work advantageously well with conventional diffusers used in connection with existing field lamp projectors and optical distance indicators. Additionally, LEDs having such characteristics illuminate well on patient skin. That is, even though such an LED results in a 2 lux reduction relative to conventional halogens, the color temperature of the LED appears brighter to the human eye when projected on skin. One example of an LED that has been tested and found to be suitable includes the Luxeon Rebel LED (Part No. LXML-PWC2) mounted on a 10 mm circuit board. As mentioned above, the light source 47 of the present disclosure must be connected to a power source 58 (as shown in FIG. 6) in order to generate the desired cone of light 70. The power source 58 used in conventional devices include AC power sources and, therefore, the present disclosure further includes a pair of LED drivers 72 connected in parallel between the power source 58 and light source 47, as depicted in FIG. 6. In one version, the parallel drivers 72 can each include a 500 mA AC/DC LED driver such as the LuxDrive 7006 Buckbullet LED driver. This advantageously enables the use of the existing power supply. Referring now to FIG. 4, and as mentioned above, the radiation generating device 10 of the present disclosure can also include the optical distance indicator 28. The optical distance indicator 28 is constructed in a manner very similar to the field lamp projector 26 discussed above, but for the sake of completeness, will also be described herein. As shown in FIG. 4, the optical distance indicator 28 of the present disclosure includes a projector housing 80 and a light fixture 82. The projector housing 80 defines a socket 84 and an optical cavity 86 that intersects the socket 84. The light fixture 82 is slidably and removably disposed in the socket 84. The optical cavity 86 contains an optical assembly 88. The optical assembly 88 can include one or more lenses 90 disposed along an optical axis Ao for focusing light emitted by the light fixture 82 onto the patient 25. Additionally, in some versions, the optical assembly 88 of the optical distance indicator 28 can include a graduated lens 125 having a plurality of numbers etched, printed or otherwise carried thereon for projecting numbers onto the patient 25, as discussed above. As shown, the light fixture 82 of the presently disclosed version of the disclosure includes a base plate 92, a grip plate 94, a bearing member 96, and a light source 97. In some versions, the base plate 92, grip plate 94, and bearing member 96 can be constructed from a single piece of material such as aluminum, for example, which may be anodized to reduce glare and reflections. In other versions, the base plate 92, grip plate 94, and bearing member 96 can be constructed of different pieces assembled together by welding, brazing, adhesive, or any other suitable means. With continued reference to FIG. 4 and additionally to FIG. 5, the base plate 92 can include a generally flat plate having a first surface 100 and a second surface 102 that is opposite the first surface 100. Similar to the base plate 92, the grip plate 94 also can include a generally flat plate and, in the disclosed version, extends from the first surface 100 of the base plate 92. The bearing member 96 extends perpendicularly from the second surface 102 of the base plate 92. In the disclosed version, the bearing member 96 includes a bearing plate 98 and a body portion 104. The bearing plate 98 can be a generally flat plate that defines a bearing surface 106 carrying the light source 97. In the disclosed version, the bearing surface 106 is flat and disposed in a first plane P1 that is perpendicular to a second plane P2, in which the base plate 92 resides. The body portion 104 can be a cylindrical form defining a through bore 108 that at least partially overlaps with an opening 110 in the base plate 92 for accommodating electrical connections 57 (shown in FIGS. 5 and 6) such as one or more wires for connecting the light source 97 to a power source 58 (shown in FIG. 6). The light source 97 of the presently disclosed version includes a light-emitting-diode (LED) 112 mounted on a circuit board 114. In the depicted version, the light source 97 is mounted flush on the bearing surface 106 of the bearing member 96 and centered on the optical axis Ao of the optical assembly 98. So configured, and as shown, the light source 97 is adapted to project a cone of light 116 that is disposed on an illumination axis Ai, which is coaxial with the optical axis Ao of the optical assembly 98. The illumination axis Ai therefore also extends perpendicular to the first plane P1 and the bearing surface 106 of the bearing member 96. So configured, the light source 97 advantageously directs and concentrates its cone of light 116 in the desired direction along the optical axis Ao, which thereby reduces reflections and optimizes the efficiency of the device. Identical to that described above with respect to the field lamp projector 26, the light source 97 of the presently disclosed optical distance indicator 28 can include an LED having a color temperature of 5650 k, exhibiting 235 lumens when running at 700 mA, or 320 lumens when running at 1000 mA. LEDs having such characteristics work advantageously well with conventional diffusers used in connection with existing field lamp projectors and optical distance indicators. Additionally, LEDs having such characteristics illuminate well on patient skin. That is, even though such an LED results in a 2 lux reduction relative to conventional halogens, the color temperature of the LED appears brighter to the human eye when projected on skin. One example of an LED that has been tested and found to be suitable includes the Luxeon Rebel LED (Part No. LXML-PWC2) mounted on a 10 mm circuit board. As mentioned above, the light source 97 of the presently disclosed optical distance indicator can be connected to the same power source 58 as the field lamp projector 26. Therefore, because the power source 58 used in conventional devices include AC power sources, the present disclosure further includes a pair of LED drivers 72 connected in parallel between the power source 58 and light source 97. In one version, the parallel drivers 72 can each include a 500 mA AC/DC LED driver such as the LuxDrive 7006 Buckbullet LED driver. This advantageously enables the use of the existing power supply. From the foregoing disclosure, it can be seen that the LED light sources of the light fixtures 32, 82 disclosed herein advantageously direct and concentrate the generated light along the optical axis Ao of the respective optical assemblies 38, 88. As mentioned, this reduces and/or eliminates reflections within the housing 30, 80. Additionally, because the light sources 47, 97 are directed in this manner, the light fixtures 32, 82 do not include aperture plates disposed between the light sources 47, 97 and optical assemblies 38, 88, as are present in conventional assemblies using halogen bulbs. From the foregoing disclosure, it can be seen that both the field lamp projector 26 and optical distance indicator 28 are configured to project a pattern of light on a target (i.e., the patient 25). Specifically, this is achieved by energizing the respective LEDs 66, 112 and emitting the respective cones of light 70, 116 to produce a pattern of light on the patient 25. The respective cone of light 70, 116 is emitted along the respective illumination axis Ai with the respective light source 47, 97. Each light source 47, 97 is carried by a projector housing 30, 80 of the radiation generating device 10 and the illumination axis Ai is disposed coaxially with an optical axis Ao of the respective optical assembly 38, 88, which is also carried by the projector housing 30, 80. With the field lamp projector 26 of the present disclosure, emitting the cone of light 70 advantageously produces a pattern of light on the patient which comprises an estimation of a pattern of radiation on the patient 25, which can also be more accurate than estimations provided by conventional halogen light. In contrast, with the optical distance indicator 28, emitting the cone of light 116 includes emitting the cone of light 116 through the optical assembly 88 including the lens 125 carrying the plurality of numbers. So configured, the pattern of light that is projected onto the patient 25 includes one or more numbers indicating a distance between the radiation generating device 10 and the target 25. Once a technician is suitably satisfied with the patterns projected by the field lamp projector 26 and/or optical distance indicator 28, the radiation generating device 10 can be energized to project a radiation field onto the patient 25 in a targeted and specific manner. Additionally, from the foregoing disclosure, it can be seen that either or both light fixtures 32, 82 of the disclosed projectors 26, 28 can easily be installed into an existing radiation generating device 10 as an upgrade over conventional light fixtures utilizing halogen bulbs. To initiate such an upgrade, a technician can first remove a cover 101 (shown in FIG. 1) from the collimator 20 of the radiation generating device 10, to expose the internal hardware. Then, any existing light fixture can be disconnected from the power source 58. Before or after such disconnection, the existing light fixture can be removed from the light fixture housing 30, 80 by sliding the existing light fixture out along a linear axis Aa (as shown in FIGS. 2 and 4) of the housing socket 64, 84. With the existing light fixture disconnected and out of the way, the upgraded light fixture 32, 82 can be connected to the power source 58 and installed. For installation, the upgraded light source 47, 97 is centered on the optical axis Ao of an optical assembly 38, 88 carried by the respective housing 30, 80. This is achieved by sliding the upgraded light fixture 32, 83 into the respective socket 64, 84 along the linear axis Aa. Once connected, the cover 101m of the collimator 20 can be re-attached to the radiation generating device 10 and the upgrade process is complete. The foregoing description is provided as one or more examples embodying the present invention but is not intended to limit the scope of the invention. The scope of the invention is defined by the following claims and includes all equivalents thereof that fall within the spirit and scope of the claims and the disclosure as a whole.
046474242	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention: The present invention relates generally to nuclear reactor facilities, and more particularly to a system incorporated within the nuclear reactor refueling machine which is capable of remotely mechanically latching fuel assemblies to, and remotely mechanically unlatching the assemblies from, the lower core support plate of the reactor internals, in addition to being capable of conventionally gripping the core fuel assemblies as well as raising, lowering, or transporting the assemblies during the performance of refueling operations. 2. Description of the Prior Art: As is well known in the nuclear reactor art, fuel, conventionally in the form of pellets, is inserted within suitable cladding material, and the composite assemblage of the fuel pellets and the cladding material or casings serve to define or form the nuclear reactor fuel rods. In turn, a predetermined number of fuel rods, assembled or secured together by means of bands called grid straps, serve to form or define a fuel element or fuel assembly, and a predetermined number of fuel elements or fuel assemblies serve to define or form the nuclear reactor core. As a result of the normal operation of the nuclear reactor facility, the nuclear fuel within the core fuel assemblies naturally becomes depleted, and consequently, the reactor core fuel assemblies must be periodically replaced and refueled. This is achieved by means of conventional refueling operations and techniques. In particular, the fuel within the reactor core fuel assemblies is depleted over a predetermined period of time and at a predetermined consumption rate such that once an initially new reactor facility has attained its steady state fuel consumption activity or operation through means of having undergone, for example, an initial two-year stabilization period of operation, each fuel assembly utilized within the reactor core will have a service life of three years. In lieu of refueling the entire reactor core once every three years by replacing all of the core fuel assemblies with newly fresh fuel assemblies, maintenance requirements and economic considerations have dictated that the reactor core be refueled once per year, during which period the reactor facility is of course shut down. In order to achieve or accommodate such requisite refueling operations, the reactor core is sectionalized, and the fuel supply relatively staggered between the core sections or stages. Specifically, the reactor core fuel assemblies are effectively arranged within three groups, sections, or stages, including a first, central circular section, a second intermediate annular section disposed about the first central section, and a third outermost annular section disposed about the second intermediate annular section. In addition, as a result of the aforenoted initial two-year stabilization period of operation, at the end of any subsequent one-year period of operation, the nuclear fuel disposed within the fuel assemblies of the innermost or first central section of the reactor core, which fuel assemblies have been disposed within the reactor core for an operational period of three years, will have been substantially entirely depleted. Similarly, the nuclear fuel disposed within the fuel assemblies of the second intermediate or middle section of the reactor core, which fuel assemblies have been in operational service within the reactor core for a period of only two years, will be sufficient so as to permit such fuel assemblies to provide service within the reactor core for an additional period of one year. In a like manner, the nuclear fuel disposed within the fuel assemblies of the third outermost section of the reactor core, which fuel assemblies have been in operational service within the reactor core for a period of only one year, will be sufficient so as to permit such fuel assemblies to provide service within the reactor core for an additional period of two years. In accordance with conventional refueling techniques, then, the fuel assemblies from the innermost or central section of the core are removed from the reactor core for actual refueling with fresh or new fuel, while the fuel assemblies disposed within the intermediate or middle section of the core are transferred to the first central section of the core. Continuing further, the fuel assemblies disposed within the outermost third section of the core are transferred to the second intermediate or middle section of the core, while entirely new or fresh fuel assemblies are inserted into the outermost third section of the core, thereby completing the refueling operation of the reactor facility. The fuel assemblies must of course be fixedly secured to the upper and lower core support plates of the reactor so as to be securely stabilized under the influence, for example, of the hydraulic forces attendant the coolant which is circulated throughout the reactor core during operation of the facility. However, in view of the foregoing requirements of the refueling operations, the assemblies must likewise be capable of being readily disconnected from the upper and lower core support plates so that the refueling operations may in fact be performed. In order to accomplish the foregoing attachment and stabilization goals, the fuel assemblies have been conventionally provided with suitable spring packs or assemblies. As the reactor facility technology has become more sophisticated, however, including, for example, an increase in coolant circulation requirements, the intensified hydraulic flow rates and forces attendant such increased coolant circulation requirements has correspondingly necessitated the need for increasingly more complex and costly spring packs or assemblies. Still further, while the fuel assemblies and core internals elements or structures of older generation reactor facilities were all fabricated from stainless steel, the fuel assemblies of the newer generation reactor facilities have been fabricated from zirconium in view of the lower neutron absorption characteristics of such material. As a result of this difference in materials, and the corresponding difference in the coefficients of thermal expansion characteristic of such materials, conventional fuel assemblies exhibit considerable thermal growth properties relative to the upper and lower core support plates. Consequently, the aforenoted spring assemblies or spring packs had to be modified further so as to include operational features which would permit the spring assemblies or spring packs to operationally accommodate such thermal growth properties, in addition to preserving the aforenoted attachment and stabilization requirements, of the fuel assemblies. These structural modifications have of course increased the complexity and cost factors of the fuel assembly spring packs still further. In view of the foregoing, recent developments in nuclear reactor fuel assembly technology have resulted in the fabrication of fuel assemblies which can be mechanically connected, for example, to the lower core support plate of the reactor internals, and in this manner, the aforenoted complex and costly fuel assembly spring packs have been able to be eliminated. A need, however, exists for technology which will permit and facilitate the remote latching and unlatching of such mechanically-connectable fuel assemblies to and from the lower core support plate of the reactor internals. Accordingly, it is an object of the present invention to provide a new and improved nuclear reactor refueling machine. Another object of the present invention is to provide a new and improved nuclear reactor refueling machine which will satisfy the aforenoted need for technological apparatus which is capable of remotely latching and unlatching mechanically-connectable fuel assemblies to and from the lower core support plate of the reactor internals. Yet another object of the present invention is to provide a new and improved nuclear reactor refueling machine which, in addition to its capability of remotely latching and unlatching mechanically-connectable fuel assemblies to and from the lower core support plate of the reactor internals, is also capable of gripping the fuel assemblies, and raising, transporting and lowering the fuel assemblies during the performance of a refueling operation within a nuclear reactor facility. Still another object of the present invention is to provide a new and improved nuclear reactor refueling machine wherein all of the apparatus or equipment which is required for the performance of the various functions or procedures attendant a refueling operation, such as, for example, the gripping of a particular fuel assembly within the reactor core, the remote unlatching of the same from the lower core support plate of the reactor internals, the raising of the fuel assembly relative to the reator core, the transporting of the fuel assembly to a new core location as may be desired, the lowering of the fuel assembly into the new core location, the remote latching of the newly deposited fuel assembly to the lower core support plate, and the disconnection of the gripping mechanisms from the fuel assembly top nozzle, may be incorporated, in a substantially co-axial manner, within a single mast of the refueling machine. SUMMARY OF THE INVENTION The foregoing and other objectives of the present invention are achieved through the provision of a nuclear reactor refueling machine which, in accordance with the present invention, includes a conventional, vertically disposed outer or stationary mast suspendingly supported by means of a support tube mounted upon the refueling machine trolley, and a co-axially disposed inner mast or fuel assembly gripper tube which is telescopically movable in the vertical direction relative to, and within, the stationary outer mast. The fuel assembly with which the apparatus of the present invention is operatively associated includes a vertically disposed latching/unlatching screw, the lower end of which is provided with an Acme thread for threadedly engaging a threaded female socket defined within an insert fixture fixedly secured within the lower core support plate so as to secure the fuel assembly to the lower core support plate. While the lowermost regions of the latching/unlatching screw is in the form of a substantially solid rod, the upper regions of the screw is in the form of a hollow tube, with the lower end of the tubular portion having a hexagonally shaped female socket defined therein. The tubular portion of the latching/unlatching screw serves as a guide tube for an extension or latching/unlatching rod vertically disposed in a co-axial manner upon the refueling machine and within the fuel assembly gripper tube, and the lower end of the latching/unlatching rod is provided with a hexagonally shaped male head for rotatably mating with the hexagonal socket of the latching/unlatching screw. The upper portion of the latching/unlatching rod is fixedly mounted within a substantially square-shaped housing which is, in turn, confined within a substantially square-shaped torque-transmitting tube. The torque tube has a spur gear fixedly mounted upon the upper end thereof, and the torque tube spur gear is engaged with another spur gear, which is mounted upon the outer stationary mast of the refueling machine, through means of an idler gear mounted upon the inner mast or gripper tube. Rotational drive is imparted to the stationary mast spur gear through means of a suitable motor mounted either upon the upper end of the stationary mast or upon the refueling machine trolley, and such rotary drive motion is transmitted to the torque tube-latching/unlatching rod assembly through means of the idler gear and torque tube spur gear. Consequently, a latching or unlatching operation can be performed depending upon the direction of the rotary drive imparted to the latching/unlatching rod-latching/unlatching screw assembly. Ratchet-type locking means is also provided within the top nozzle of the fuel assembly for engagement with the upper end of the fuel assembly latching/unlatching screw for preventing retrograde rotary motion of the screw once the screw is fully threadedly engaged within the lower core support plate fixture or adapter so as to prevent inadvertent unlatching of the screw and the fuel assembly from the lower core support plate.
	description	This application is a continuation of International Patent Application No. PCT/DE2004/000924 filed Apr. 29, 2004, the publication of which by the International Bureau was not in the English language. This application also claims priority under 35 U.S.C. 119(d) to German Patent Application No. DE 103 19 154.2, filed Apr. 29, 2003. The entire contents of each of the above-identified applications are incorporated herein by reference. 1. Field of the Invention The present invention relates to a maskless lithography system for direct, nano-scale capable structuring of a substrate disposed on a movable mounting table in a vacuum chamber supplied with a high voltage, using a charged particle beam generated by a beam source, and an addressable digital pattern generating system onto which the structure pattern to be generated is transmitted as a set of pattern data generated with computer assistance using a data transmission system. 2. Brief Description of Related Art Particle beam lithography plays a major role in the manufacture of devices in the field of microsystem-technology and monolithically integrated circuits in electronic, opto-electronic, optical and other embodiments, and their individual components, which comprise nano-sized structures measuring 100 nanometers and less. The geometrical structure to be produced on a substrate, typically a wafer, is converted into a set of pattern data with the assistance of a computer. Said set of pattern data is either used for manufacturing a mask that cannot be changed, a large area of which is being irradiated (indirect structuring technique), or said set of pattern data is continually worked off by suitably addressing the particle beam and the mounting table, on which the substrate to be structured is disposed (direct structuring technique). The indirect structuring technique is advantageous in that it enables parallel, and therefore very fast realization of the structure pattern. It has, however, also a disadvantage because of the extremely expensive manufacturing of the masks which can only be balanced by mass production of circuit layouts, because of the transfer of errors in the mask and because of the rather complex alignment when the mask is brought into position. Therefore, at present the direct structuring technique is being intensively developed further, since it offers the great advantage of flexibility with respect to the geometrical structure patterns that can be manufactured, which makes it ultimately less costly. However, this method has the disadvantage of a relatively low through-put of substrates as a result of the slow, serial structuring process employing the particle beam. Therefore, a greatest possible parallelization is also aimed at in the direct structuring method. For achieving this parallelization, different concepts are being pursued. On one hand, a plurality of parallel particle beams may be generated; on the other hand a programmable, changeable mask comprising electrically-addressed individual elements (apertures) as a pattern generating system may be irradiated with a homogeneous particle beam having a large cross section. The data rate, which needs to be processed in this preferred concept and which comprises the data for addressing the digitized structure pattern having 600,000 mask points, for instance, which are usually irradiated several times (grey scale system, comparable to the principle of the ink jet printer), and the addressing of the mounting table, is extremely high, and easily reaches several Tbit/s, such that suitable transmission of the data rate to the pattern generating system inside the vacuum chamber of the lithography system constitutes a particular problem associated with the direct structuring technique. U.S. Pat. No. 6,379,867 B1 discloses a lithography system that is designated “maskless” since no unchangeable, rigid mask in a conventional sense is employed. Rather, the pattern generating system is configured as a pixel panel, which comprises a plurality of addressable individual elements, for instance, formed by digital mirror devices (DMD), which either transmit or block the light beam. The pattern to be generated is generated as a bitmap with the assistance of a computer, it is then stored in a storage device, and transmitted from there via a wire-bound signal connection to the pattern generating system. The data transmission system is based exclusively on a wired connection. Therefore, in order to achieve the high data transmission rate, a multitude of wire-bound data lines needs to be guided into the inside of the vacuum chamber of the lithography system, and needs to be contacted there. Thus, problems arise with the respect to their spatial arrangement and allocation, and in particular with respect to the mechanical fixation of the data lines to the carrier plate of the individual element to be addressed. Furthermore, removing the data lines for purposes of maintenance in the vacuum chamber is very complex. In addition, negative effects on the data to be transmitted may occur due to the conditions inside the vacuum chamber, in particular due to the applied high voltage. It is an object of the present invention to provide a lithography system having an addressable pattern generation system and having a data transmission system which enables even highest data rates to be transmitted reliably to the inside of the vacuum chamber, and in particular in which no mechanical strain on the pattern generating system due to contacts or any space related problems occur. It is an additional object to provide simple allocation of the transferred data to the addressable individual elements in the pattern generating system. It is a further object for the data transmission system according to the present invention to be robust in terms of operation and to allow easy assembly and disassembly. Exemplary lithography systems according to the present invention provide an opto-electrical free-space beam connection system as the data transmission system, by which the pattern data optically converted to corresponding optical signals by electro-optical converters are distributed at light exit locations, such that the pattern data embodied in the optical signals are transmitted by optical free-space beams (i.e., optical beams not bound to a material medium, also called “free beams” herein) whose orientation is adjustable. The adjustable optical free beams are transmitted onto light entry locations inside the vacuum chamber, from where they are guided to opto-electrical converters, which are associated with the pattern generating system with respect to the transmitted pattern data. The number N of the electro-optical converters can be adapted to the pattern data rate to be transmitted, based on their predetermined conversion rate. Such an arrangement facilitates both the transformation of the high data rate to be transmitted into the efficient optical range as well as the data transfer in a free beam connection system, which date transfer is not dependent on wiring (data lines). The opto-electrical data transmission system in the lithography system permits keeping the pattern generating system free from cumbersome wire-bound and mechanically straining connections to the outside, and thus enables relief from mechanical strain. Therefore, upon assembling or maintaining the lithography system, cumbersome wired connections for data transmission do not need to be made or removed directly at the pattern generating system. In the present invention, the entire data transmission is based purely on optics and is independent of wiring, at least directly in front of the pattern generating system, owing to the integration of a free beam connection system. The opto-electrical data transmission system is very efficient, so that even the highest data rates can be transmitted. The electro-optically converted data are guided as parallel free beams directly to the pattern generating system, with the number of the parallel free beams being adapted to the data rate to be transmitted via the predetermined transmission rate of the electro-optical converters. Assuming an exemplary data rate of 10 Gbits/s per electro-optical converter, 256 parallel free beams are required for transmitting a data rate of 2.56 Tbit/s. These parallel free beams' paths are directed at the opto-electrical converters in the pattern generating system. From there, the data, which are converted into electrical signals, are guided to the individual elements of the pattern generating system via subsequent signal processing. In an exemplary embodiment, the opto-electrical converters in the pattern generating system accordingly detect the incoming optical data at their data rate of 10 Gbits/s. In the region of the free beams, which are independent of wiring, the light serving as the data carrier in the vacuum chamber is neither influenced by the high voltage present therein during structuring, nor by the particle beam, whose particles are usually ions or electrons. This has a great advantage in that the data can be optically irradiated directly onto the opto-electrical converter—accepting that their paths cross the particles' paths—without occurrence of any problems with respect to potentials. Space consuming and complex bundles of wiring and their mechanical contacting are not required. Different embodiments of an optical free beam connection system, which may be used in the present invention, are generally known form the state of the art, typically, however, in the context of powerful communication devices, but also for data transmission to inaccessible locations (see for instance, EP 0 485 071 A2, therein data transmission to a hermetically encapsulated device underwater is described), or to locations which are difficult to contact (see for instance DE 100 36 237 A1, therein a modular construction of a machine of individual, electrically controlled functional units is described, between which data are optically transmitted). From the final report of the project “Optical Signal Processing” (edited by the Heinrich-Hertz-Institut für Nachrichtentechnik Berlin GmbH, July 1994, Chapter D.6.2.2), for instance, an optical 3D spatial step is known, which is formed by a cascaded electronic circuit and optical free beam connection steps comprising Fresnel zone lenses for collimating or focusing, respectively, as well as volume holograms for beam deflection. It is a free beam connection network for transmission of transmission rates in a Gbit range, as it may be used for optical signal processing in an OFDM-switching system. The free beam connection system in the lithography device according to the present invention is, in the present context, principally understood as a serial combination of light exit locations functioning as optical emitters (for instance active light emitters, such as electro-optical converters, for instance laser diodes, or exits of light wave guides), free beams independent of wires (wire-unbound) and light entry locations functioning as optical receivers (for instance active receiving elements, such as opto-electrical converters, for instance photo diodes, or entrances of light waveguides). It is optional how the data are provided and picked up at the light entry and light exit locations. Furthermore, the positioning of the free beam connection system may be chosen freely and is therefore adaptable in particular to the constructional environment and requirements. In a simplest embodiment, the free beam connection system comprising the components listed above is disposed directly in front of the pattern generating system. The distance covered by the free beam is therefore very short. The contact-free data input allows the pattern generating system to be relieved from mechanical strain, which is one of the main objects of the present invention. In this embodiment, the data transmission to the electro-optical converters may take place in a wire-bound manner (electrically or optically), wherein passages for wires need to be provided in the wall of the vacuum chamber, accordingly. Furthermore, the light exit locations of the free beam connection system inside the vacuum chamber may be disposed at a greater distance from the pattern generating system, which results in a lengthening of the distance covered by the free beams. In this respect, it is advantageous, if, according to an exemplary embodiment of the present invention, optical deflection arrangements are disposed in the free beams inside the vacuum chamber. Thus, any constructional environments inside the vacuum chamber may be accommodated and the free beams guided to the light entry locations irrespective of these constructional environments. The deflection arrangements, which may be disposed in the middle of the free beam distance, or also directly in front of the light exit or entry locations, may be provided by adjustable micro mirrors or micro prisms, for example. According to a further embodiment of the present invention, the light exit locations may be disposed outside the vacuum chamber, and the free beams may be guided into the vacuum chamber through a light transparent window in the vacuum chamber. In this way, the data transmission to the inside of the vacuum chamber is already independent of wiring and achieved by free beams. The free beams are guided simply through a window, which is integrated into the wall of the vacuum chamber. When the light exit locations are positioned outside the vacuum chamber, space requirements and efforts associated with mounting the free beam connection system inside the vacuum chamber are reduced. No passage for any wiring for data transmission into the inside of the vacuum chamber is required, and a complete decoupling from the high vacuum and from the high voltage fields inside the vacuum chamber results. Deflection of the free beams, which enter the inside through the window, onto the opto-electrical converters is again readily achieved by optical deflection arrangements. Any suitable deflector may be used. In order to save space outside the vacuum chamber also, a further embodiment of the present invention provides that the light exit locations are disposed directly at the window from the outside. Thereby, a series of further constructional simplifications may result, which are discussed further below. In addition, the light exit locations may advantageously be disposed orthogonally below the window, and the free beams may be guided via an additional optical deflection arrangement through the window into the inside of the vacuum chamber. Thus, deflection arrangements may also be provided outside the vacuum chamber in order to be able to guide the free beams in an optimal space saving manner. Finally, according to a further embodiment of the present invention, the window may also be recessed into the vacuum chamber. This enables a space saving positioning of the light exit locations on the outside, but still within the region of the vacuum chamber. Furthermore, predetermined optical distances may be met more easily. This is described in more detail later on in the general description and the exemplary embodiments. In order to avoid interfering influences due to stray light and other effects, when free beams are irradiated from external light exit locations through the window, it is particularly advantageous if the window is provided with a cover shielding against external light and electromagnetic fields in a region outside of the passing free beams. The covers may be simple mechanical or optical covers. Furthermore, the free beams may be grouped into arrays, which are locally precisely defined and whose surrounding is therefore easier to cover. Using suitable light sources, the generated free beams may be guided without use of any further optical measures over short distances in a cm range, in particular. However, it is preferable if, according to a further embodiment of the lithography system according to the present invention, collimating and focusing micro lenses are disposed at at least one of the light exit locations and light entry locations. This allows grouping and exact orientation of the free beams. At which position micro lenses are disposed in the free beams depends on the quality of the individual employed elements. Furthermore, losses due to large diffraction angles is avoided, and angular arrangement of the free beams from the light exit locations and towards the light entry locations is possible. The micro lenses may, for instance, be configured as Grin or Fresnel zone lenses. Due to their optical properties, they may only be used in connection with relatively small free beam distances. As already described above, arrangement of the light exit locations in an array is advantageous and saves space. The same also applies to arranging the light entry locations in a common array. In these embodiments of the present invention, the array may be one dimensional, forming a line or column, or, in a compact embodiment, it may be two dimensional with lines and columns of light entry locations and light exit locations, respectively. If an array arrangement is used, according to a further exemplary embodiment of the present invention, the array of the light exit locations may advantageously be imaged by an imaging optics onto the array of light entry locations. Thereby, also longer distances covered by the free beams from 10 cm up to the range of meters can be realized. If an imaging ratio of 1:1 is chosen, and if a simple imaging lens is used as the imaging optics, said imaging lens needs to be disposed symmetrically between the light exit locations and the light entry locations (object width=image width). In order to avoid distances becoming too long, the window may be moved into the vacuum chamber, for instance, as already described above. If other imaging ratios are chosen, or if more complex lens arrangements employed as imaging optics, asymmetric arrangements of the imaging optics or differences in size of the array dimensions may be considered, accordingly. If an imaging lens is employed, the light entry locations inside the vacuum chamber need to have an arrangement relative to the light exit locations, which is mirror-inverted with respect to the vertical and/or horizontal middle axis (depending on the embodiment of the imaging lens). As already discussed above, the light exit locations in free beam connection systems serve to emit light and the light entry locations serve to receive light. The locations may differ in terms of their construction, and in particular, they may be configured to be passive or active. In accordance with a further embodiment of the present invention, the light entry locations and/or light exit locations may be formed by the ends of light waveguides. Thus, in this passive embodiment, the data may be already optically converted and then guided to the light exit locations, in particular, by light waveguides. Furthermore, the light entry locations may also be connected via light waveguides with the opto-electrical converters. The light waveguides may be provided by light fibers which are suitable for being combined into a bundle, for instance glass fibers, which show little loss and are not prone to interferences, or by monolithically integrated waveguides. Furthermore, if the light waveguides are formed by light fibers, the ends of the light waveguides may be combined into a bundle to form a fiber array plug. Use of fiber array plugs makes maintenance particularly easy and allows easy maintenance. Furthermore, susceptibility to errors is reduced, since the individual light waveguides are fixedly arranged in the fiber array plugs, and fiber array plugs enable correctly aligned and allocated connections. When using 256 parallel light waveguides, as an example, four connection bundles comprising 64 light waveguides each may be formed. Each bundle then terminates in a “64 pole” fiber array plug. Fiber array plugs of this kind (“Ferrel”) are generally known in the art (see for instance internet page www.xanoptix.com/Ferrell.htm; status of Mar. 14, 2003) and are commercially available. If the light exit locations are configured to be active, a further embodiment of the present invention advantageously provides that the electro-optical converters as light exit locations are configured as emitting lasers. Thus, electro-optical conversion of the pattern data occurs only directly at the light exit location. Providing a wire-unbound feed line to the emitting laser does not cause any problems, in particular if the feed line is disposed outside the vacuum chamber. Active light entry locations may also be realized by configuring the opto-electrical converters as light entry locations formed by photodiodes, according to a further embodiment of the present invention. The data are opto-electrically converted directly in the light entry locations and passed on in a wire-bound system. In an embodiment comprising active emitting elements (for instance emitting lasers) and active receiving elements (for instance photodiodes), no light waveguides are required, which results in a particularly compact embodiment. Other active components may also be used. The opto-electrical converters formed by photo diodes require less than 50 micrometers of space, for instance. Assuming a distance between the individual photo diodes in a range of 250 micrometers to 500 micrometers, for transmitting a sum data rate of 2.56 Tb/s by 256 parallel light waveguides and thus 256 photodiodes arranged in a row, each of which is used for addressing a group of individual elements (apertures), a space requirement for the diode array in the one direction of between 64 mm and 128 mm results. Such a band-shaped diode array may be disposed on the so called “blanking plate”, which holds programmable chips comprising the individual apertures, in a known lithography system. Such a programmable aperture system is known, for instance, from the abstract of the publication “Programmable Aperture Plate for Maskless High Throughput Nanolithography”, by I. L. Berry, et al.; (Journal of Vacuum Science and Technology, B, 1997, Volume 15, No. 6, pages 2382 to 2386). A particular advantage of the lithography system according to the present invention, however, lies in the option that light beams and particle beams may cross one another in the vacuum chamber, and that therefore, there is the option of a free choice of arrangement and accessibility of the opto-electrical converters. That way, particularly space saving arrangements may be realized. Furthermore, major advantages result from the speed of data transmission of the blanking plate, since shorter distances may be realized. According to a further embodiment of the lithography system according to the present invention, it is therefore advantageous if the opto-electrical converter is disposed directly in the pattern generating system. Accessibility of the converters via the free space distance in the vacuum chamber is always granted. Complex, sensitive and obstructing wiring, which is also critical with respect to achievable data speeds, is not required. In exemplary embodiments, the pattern generating system can be configured as a programmable aperture plate system, and the photodiodes may thus be distributed over the blanking plate and may be allocated there to groups of apertures via multiplex elements, whereby a major simplification of the arrangement and spacing savings can be achieved. The free light beam carrying data on the respective optical light path is typically focused and collimated by optical elements and, accordingly, oriented in terms of its path direction. Upon assembly, maintenance or even during operation, undesired changes of adjustment may occur due to mechanical tolerances and changes of shape, both upon alignment of the beam as well as at the location of the detector or converter, respectively. Therefore, it is advantageous if, according to an exemplary embodiment, an adjustment system is provided for aligning the free beams with the light entry locations, which adjustment system lends itself to automation. The adjustment system may already directly access the light exit location, and produce a correction of the position of the light exit locations, for instance. According to a further embodiment of the present invention, the adjustment system may be disposed in the beam path of the free beam connection system. Thus, the correction in the optical range is effected by respective optics, which is easy to realize from a constructional point of view. Furthermore, electrical or optical feedback signals from the vacuum chamber may be used for alignment. According to a further embodiment of the present invention, it is advantageous if additional electro-optical converters are disposed in a region of the pattern generating system, by which further optical signals in a back direction, in particular monitoring and control signals, may be generated and guided via free beams onto additional opto-electrical converters, wherein the further optical signals may be used as feedback signals for the adjustment system, which may be automated. Four-quadrant-photodiodes may be used for detection, for instance, which enable precise orientation of the beam by suitable adjustment arrangements, for instance in a beam path, on the basis of divided quadrants measurements. This back path may also be used to transmit test sequences—once or at repeated time intervals—which provide information on the proper functionality of the optical data transmission system and the structuring system. The present invention can facilitate electro-optical data transmission into and from a closed, badly accessible space having extreme conditions on its inside using a free beam connection system. Additionally, it is, however, possible—at least for relatively small amounts of energy—to realize an optical transmission of energy into the inside of the vacuum chamber without use of wires, in order to induce a process in the vacuum chamber, for instance, such as a switching process, to generate an electrostatic field or to charge up an energy storage. According to a further embodiment of the present invention, an optical energy transmission onto the addressable pattern generating system may be advantageously carried out using the opto-electrical free beam connection system. FIG. 1 schematically shows a section of a maskless lithography system 1 according to the present invention for direct, nano-scaleable structuring of a substrate 2, for instance a wafer made of silicon, which is disposed on a moveable mounting table 3. A cross-section of vacuum chamber 4 is depicted, the vacuum chamber 4 having a potential of 100 kV, for instance, on the inside. A homogeneous, broad particle beam 5, comprising electrons in this instance, is guided from the particle source, which is disposed in high vacuum, from the top into the vacuum chamber 4, wherein it is incident on an addressable pattern generating system 6 disposed above substrate 2. In the pattern generating system 6, which preferably is a programmable aperture plate system, a digital structuring pattern for irradiating substrate 2 with the particle beam 5 is generated with the assistance of a computer. To this effect, individually addressable apertures 7, which form the points of the structure or individual elements, respectively, are addressed in dependence of their positions in the structuring pattern to be generated and in dependence of their positions above the moveable substrate 2. In case of very fine structures and a high irradiating speed, the data rate to be transferred is very high and may be in the range of Tbit/s. The pattern generating system 6 receives the data for the addressing process via an opto-electrical free beam connection system 8 (also referred to as a data transmission system). In the depicted embodiments, said system comprises electro-optical converters 9, light exit locations 10, free-space beams 11 (i.e., optical beams not bound to a material medium, which may also be referred to herein as free beams), light entry locations 12 and opto-electrical converters 13. The electrical pattern data are converted electro-optically to optical signals, and the optical signals (which may also be referred to herein as pattern data for brevity) are then transmitted by free beams 11 onto the pattern generating system 8, and are further processed there as control data, after their opto-electrical conversion. The number N of free beams 11 (and thus of the electro-optic converters 9 and the opto-electrical converters 13) is adapted to the transmitted total-data-rate via the predetermined conversion rates of the electro-optical converter 9. In this context, it is to be noted at this point that the individually depicted components may be arranged as an array. For the transmission of a data rate of 2.56 Tbit/s, N=256 parallel free beams 11 with a data rate of 10 Gbit/s to be generated by the electro-optical converters 9 are required. In the depicted embodiment, both the light exit locations 10 as well as the light entry locations 12 (each depicted schematically) are disposed within the vacuum chamber 4. In this way, a very short free beam distance may be realized which serves to mechanically relieve the pattern generating system 8 by rendering contacting unnecessary. In this case, the free beams 11 may be grouped by collimating microlenses 14 and focusing microlenses 15. For deflection, the free beams 11 are deflected by deflection arrangement 16, for instance micro-mirrors, by 90°, in the depicted embodiment. The deflection arrangements 16 are principally arranged such that the particle beam 5 is not impeded. In the depicted embodiments, the light exit locations 10 are formed directly by active emitting lasers 17 as electro-optical converters 9. The pattern data, which are thus provided as electrical signals, are supplied in a wire-bound fashion using wires, which are guided through passages 18 in the wall of the vacuum chamber 4. If the electro-optical converters 9 are disposed outside the vacuum chamber 4, supply of optically converted data to the inside of the vacuum chamber may also be carried out using light waveguides. The light exit locations 10 are then disposed at the ends of the light waveguides. The light entry locations 12 are formed directly by receiving elements, in the depicted embodiment, for instance by photodiodes 19, as opto-electrical converters 13. Optionally, in such an embodiment having a very short free beam distance, microlenses 14, 15 may also be omitted. In FIG. 2, an embodiment of the present invention having a long free beam distance is shown, in which light exit locations 10 of the free beam connection system 8 are disposed outside the vacuum chamber 4 and are formed by the ends of passive light waveguides 20, at the front end of which electro-optical converters 9 are positioned (active emitting elements are also possible in this case). Also in this embodiment, pre-collimating microlenses 14 may be provided at the ends of light waveguides 20. Focusing microlenses 15 are also depicted, they may be omitted, however. The free beams 11 are guided through a window 21, which may be a simple glass pane, in the wall of the vacuum chamber 4 into the inside of the vacuum chamber 4. In order to provide shielding against interferences, the window 21 is provided with a cover 22. Because of the great distance between the light exit locations 10 and the light entry locations 12, an imaging lens 23 is provided, which images the respective locations onto one another. In particular, compact array-arrangements of light exit locations 10 and light entry locations 12, also in connection with readily removable fiber array plugs, may be imaged well using imaging optics 23, which is formed by a simple imaging lens in this instance. Also, if imaging optics 23 is used, the arrangement thereof should not impede particle beam 5, the free beams 11 may be guided along an angular path by using a deflection arrangement 24, which does not impede particle beam 5, either-, wherein said optical deflection arrangement receives all free beams 11 together, which are positioned close to one another. FIG. 3 shows an embodiment of an arrangement, which is linear throughout, with dimensions indicated, and wherein the light exit locations 10 are disposed outside the vacuum chamber 4 (suggested only). These light exit locations 10 are formed by a fiber array plug 30. In the chosen embodiment, the fiber array plug 30 comprises (6×12) light waveguides 20 provided by glass fibers and two photodiodes (four quadrant) for receipt of feedback signals. The bundle of free beams 11 is guided via the imaging lens 23 through the window 21 and via an optical deflection arrangement 24 onto a photodiode array 31. Apart from the (6×12) photodiodes, the photodiode array 31 in the chosen embodiment also comprises two emitting lasers 32 (VCSEL) for generating feedback signals. These are guided back to the two photodiodes having a four-quadrant-configuration in fiber array plug 30 and serve to control the alignment of free beams 11 with the photodiode array 31. Any occurring deviation is optically compensated for in an adjustment system 33, which is suitable for automation, and which is disposed in the free beam path. A mechanical, automated or manual adjustment, for instance by a displacement of fiber array plug 30, is also possible. In the chosen embodiment, photodiode array 31, which is disposed on a carrier plate 34 having square openings, is configured as a combination with an electronic chip, and also comprises the first stop of the demultiplexer for distributing the received, opto-electrically converted pattern data. A further electronic chip having corresponding openings is not depicted. The entire system is referred to as programmable aperture plate system 35. Details of the imaging lens 23 may be derived from FIG. 4. Plural light waveguides 20 are combined therein to a line-shaped fiber array 40. A combination into lines and columns in a fiber array plug (see above) for achieving even more compact dimensions and a simpler assembly is also possible. A mirror-inverted image of the line-shaped fiber array 40 is imaged by the imaging lens 23 through the window 21 onto a line-shaped light entry array 41 (indicated in FIG. 3 by beam lines). An approximately 1:1-imaging optics 23 comprising a simple imaging lens is depicted, which allows a large working distance in the free beam path. In case of an asymmetric arrangement of imaging optic 23, other imaging ratios may be chosen. In the chosen embodiment, the light entry locations 12 are formed by photodiodes, which are monolithically integrated into a semiconductor chip 42, for instance made from silicon, for a transmission wavelength of 850 nm. In FIG. 5, an embodiment comprising an arrangement of fiber array plugs 50, in which the ends of a number of N light waveguides 20 are combined, and further comprising an imaging lens 23 disposed outside the vacuum chamber 4 is depicted. The deflection of the bundle of free beams 11 is achieved by the additional optical deflection arrangement 52, which is disposed at about the same height as window 21. Both the fiber array plug 50 and the optical deflection arrangement 24 are integrated into an angular cover 51, which simultaneously serves as a mechanical fixation and a shield against optical interfering influences, and also serves to protect imaging lens 23. A further optical deflection arrangement 24 is disposed inside the vacuum chamber 4 which, in the chosen embodiment, guides the bundle of free beams 11 onto a photodiode array 53. In FIG. 6, an embodiment similar to that of FIG. 5 is depicted, wherein the window 21 is now recessed into the vacuum chamber 4. The fiber array plug 50 is mounted to a plate 61, which simultaneously serves the purpose of shielding from optical interferences. The imaging optics 23 is disposed exactly in front of the window 21. Using this arrangement, smaller dimensions of the free beam connection system 8, and thus more compact constructional dimensions are achievable. In FIG. 7, a front view of fiber array plug 50 comprising two openings 71 for fixation is depicted and dimensions thereof indicated, which plug comprises, in the depicted embodiment, six lines with twelve light waveguides 20 each, which have a predetermined, in this instance the same pitch distance in the vertical and horizontal direction. In FIG. 8, possible arrangements of collimating micro-lenses 14 and focusing micro-lenses 15 in the free beams 11 to both sides of window 21 are depicted, with dimensions of the arrangements being indicated. The focusing micro-lenses 15 in front of photodiode 19 may optionally be omitted (in FIG. 8 only indicated on the right hand side). 1 . . . 64 light waveguides 20 according to the chosen embodiment are depicted. In FIG. 9, the possible angular irradiation into the photodiode 19 is depicted. This is realized by a suitable rotation (indicated by dotted lines) of the focusing micro-lenses 15 and window 21 and allows to adjust the orientation of free beams 11 to the spatial surroundings in the vacuum chamber 4. As is illustrated in FIG. 10, additional electro-optical converters 50 could be disposed in a region of the pattern generating system, by which further optical signals in a back direction, in particular monitoring and control signals, may be generated and guided via free beams 51 onto additional opto-electrical converters 52, wherein the further optical signals may be used as feedback signals for the adjustment system, which may be automated. In the drawings illustrating exemplary embodiments reference numeral 1 refers to a lithography system, 2 refers to a substrate, 3 refers to a mounting table, 4 refers to a vacuum chamber, 5 refers to a particle beam, 6 refers to a pattern generating system, 7 refers to an aperture, 8 refers to a free beam connection system, 9 refers to an electro-optical converter, 10 refers to a light exit location, 11 refers to a free beam, 12 refers to a light entry location, 13 refers to an opto-electrical converter, 14 refers to a collimating micro lens, 15 refers to a focusing micro lens, 16 refers to a optical deflection arrangement, 17 refers to an emitting laser, 18 refers to a passage, 19 refers to a photodiode, 20 refers to a light waveguide (number N), 21 refers to a window, 22 refers to a cover, 23 refers to imaging optics, 24 refers to an optical deflection arrangement, 30 refers to a fiber array plug, 31 refers to a photodiode array, 32 refers to an emitting laser, 33 refers to an adjustment system, 34 refers to a carrier plate, 35 refers to an aperture plate system, 40 refers to a fiber array, 41 refers to a light entry array, 42 refers to a semiconductor chip, 50 refers to a fiber array plug, 51 refers to a cover, 52 refers to an additional optical deflection arrangement, 53 refers to a photodiode array, 61 refers to a plate, and 71 refers to an opening for fixation. The present invention has been described by way of exemplary embodiments to which it is not limited. Variations and modifications will occur to those skilled in the art without departing from the scope of the present invention as recited in the appended claims and equivalents thereof.
	summary
	summary
	abstract	A holder for a vial containing a sterile liquid for use with a radiopharmaceutical elution system includes a holder body. The body has a top, an opposing bottom, an opening in the top and a vial chamber. The vial chamber extends from the opening in the top toward the bottom and is sized and shaped for receiving the vial therein. An access opening extends through the bottom to the vial chamber and is aligned with a septum of the elution vial when the sterile vial is received in the vial chamber. A cap is removably secured to the top of the holder body for selectively opening and closing the vial chamber. The holder body includes plastic and has a density less than the density of the cap.
	description	The invention relates to a particle-optical device for irradiating an object with a beam of particles, comprising a housing in which are located positioning means for positioning the object within the housing, comprising a reference body supported against a supporting portion of the housing and a kinematic system—which can be manipulated—with an object carrier for manipulating the object held in the object carrier in at least one degree of freedom with respect to the reference body, the device further comprising control means and at least one combination of a piezo-electric position actuator and a piezo-electric force sensor, which actuator and sensor are positioned in series, whereby the control means—in dependence upon at least one input signal from at least one sensor—generates a control signal for at least that actuator associated with said sensor. A combination of a piezo-electric position actuator and a piezo-electric force sensor, which actuator and sensor are positioned in series, is known from the technical literature, and is often referred to using the term. “Smart Disc”. In every Smart Disc, there is a control system that receives an output signal from the force sensor—in the form of a voltage signal—as an input signal for the control system and, in reaction hereto, generates a control signal for the attendant actuator. The operation of the actuator can thus be aimed at opposing the force observed by the sensor, e.g. as caused by accelerative forces associated with small vibrations, which phenomenon can be usefully exploited in opposing small vibrations. The relationship existing between the control signal generated by the control unit and the input signal received by the control unit is also referred to using the term “controller transfer”, with a certain frequency-dependent characteristic and a certain amplification factor (also referred to using the term “gain”). A particle-optical device according to the opening paragraph is known from European patent application EP 1225482 A1. Said document describes a lithographic device that uses a beam of UV, electrons or ions to process a wafer for integrated semiconductor circuits. To this end, use is made of an optical system with a lens for generating and focusing a beam of particles onto a desired position on a wafer. The optics—or more specifically their lens—are supported on a horizontal main plate via three lens supports. Each of the lens supports comprises a pair of Smart Discs. The main plate can be regarded as being connected to the fixed world via air springs and dampers with a typical eigenfrequency of the order of 1 Hz. Underneath the lens is located a wafer that is supported by a wafer table, which can manipulate the wafer in the horizontal plane and also in the vertical direction, with the purpose of following vibrations in the main plate caused by the resilience of said air springs and dampers. To this end, one or more interferometers are provided, comprising part of a control circuit that ensures that the vertical distance between the main plate and the wafer remains constant, so as to achieve a correct focus. The lens typically has a first eigenfrequency located in the range 50–150 Hz. Resonance of the lens can therefore arise as a result of environmental acoustic noise or floor vibrations, e.g. generated by apparatus surrounding the device. Such vibrations can ultimately lead to a situation whereby the accuracy of the (horizontal) positioning of the beam of particles and/or the focusing of the beam of particles on the wafer is no longer adequate. By employing the Smart Discs (of which there is a total of six, corresponding to the six degrees of freedom of the lens), the vibrations resulting from this resonance are actively damped, as a result of which an improved accuracy of the focusing of the beam of particles on the wafer can be realized. The invention aims now to provide a particle-optical device whereby resonances that influence the mutual positioning of the beam of particles and the object to be irradiated, and whose eigenfrequencies are located in a range between 75 Hz and 1000 Hz, are damped. More specific reference is hereby made in the first instance to an electron microscope, particularly a scanning electron microscope, whereby the positioning means typically have a different construction than the positioning means pertaining to a device according to EP 1225482 A1, as a result of which these positioning means will also exhibit a substantially different, more complex and dominant vibrational behavior. In this context, one should realize that samples in electron microscopes not only have to be capable of being manipulated (by the positioning means) in the plane perpendicular to the beam, but also in a direction parallel to this beam, to an extent that is significantly greater than the extent to which wafers in the device according to EP 1225482 A1 are to be manipulated in a direction parallel to the beam. In addition, the positioning means in electron microscopes are required to be suitable to tilt samples through a substantial tilt range of, for example, 60 degrees, to which end the positioning means are provided with suitable guiding means. As a result of this, the intrinsic stiffnesses of the positioning means in the case of electron microscopes are often markedly lower than the stiffnesses that can be achieved in the case of devices according to EP 1225482 A1. Moreover, it is a general fact that the stability demands made of the positioning means of an electron microscope are greater than comparable demands in the case of devices according to EP 1225482 A1. Although the invention is particularly suitable for application in electron microscopes, it is not limited hereto, and can also be applied in the case of other types of particle-optical devices, e.g. of the type described in EP 1225482 A1. In further preferential embodiments of the invention, the invention aims inter alia to optimally exploit the possibilities offered by Smart Discs for the purpose of damping vibrations, and to allow the incorporation of Smart Discs in a simple manner and at low manufacturing costs. To this end, the particle-optical device according to the invention is characterized in the first instance in that the series-positioned actuator and sensor of said at least one combination is positioned between the housing and the reference body, the support of the reference body against the supporting portion of the housing occurring via said at least one combination. The invention recognizes in this manner that, for certain types of particle-optical devices, the determining factor as regards the accuracy of positioning and of focusing of the beam on the object is not such much determined by the resonance behavior of the optics as by the resonance behavior of the positioning means, and that a very advantageous damping of such resonance vibrations can be achieved thanks to the characterizing measures according to the invention. In general, preferably at least three combinations of series-positioned actuators and sensors are provided in the case of a device according to the invention. Thanks to the invention, an improved stability can also be achieved. So as to be confronted as little as possible by the finite stiffness of the construction of series-positioned actuators and sensors itself—as a result of which, under the influence of external forces, the positioning means can be brought into unfavorable resonance at relatively low frequencies, as a result of which inaccuracies and reduced stability as regards the positioning and focusing can occur—at least three combinations are preferably positioned close to a circumferential edge of the reference body. In this context, it is also preferable that at least three combinations be positioned close to three corner points of the reference body. As a result of the fact that, normally, image disturbing resonances of the positioning means will occur in two perpendicular directions, it is preferable that two connecting lines between the positions of at least three combinations intersect each other at right angles. According to a highly advantageous preferential embodiment of the invention, a support element is positioned between the housing and the reference body, via which support element—supplementary to the support via said at least one combination—the support of the reference body against the supporting portion of the housing additionally occurs, whereby the sum of the number of support elements and the number of combinations is at least four. As will be made clear hereafter, such an embodiment can also be applied to great advantage if the series-positioned actuators and sensors of said at least one combination and said at least one support element are not positioned between the housing and the reference body, but generally between other bodies between which active damping is intended to occur via Smart Discs, such as between the main plate and the lens as in the case of the device according to EP 1225482 A1. The great advantage of supporting the reference body against the supporting portion of the housing at four positions instead of three positions lies in the fact that, in this fashion, the stiffness behavior of the reference body will be markedly more advantageous, as a result of which an increase of the eigenfrequency (which is to be suppressed/damped) of the positioning means will occur, and deformations of the reference body will be less disadvantageous, certainly if said at least four positions of support are located in four corner points (to the extent present) of the reference body. As a result of the application of four support positions, an over-determined scenario arises whereby it should be prevented that the support in fact occurs at only three support positions. Accordingly, during assembly of the device according to the invention, one should ensure that the four supporting portions, of which at least one is in the form of a combination of a piezo-electric actuator and a sensor and at least one is in the form of a support element, are accurately positioned perpendicular to the plane of the reference body so that four support positions are actually active. To this end, it is preferable that at least one of the support positions be adjustable in height. Preferably, said at least one support element comprises at least one further combination of a piezo-electric position actuator and a piezo-electric force sensor, which actuator and sensor are positioned in series, which at least one further combination is supplemental to said at least one combination, whereby the sum of the number of combinations and the number of further combinations is at least four. In this manner, one obtains great freedom as regards the manner in which resonance vibrations can be damped by the further combination—also by making use of an active element in this set-up. Another effect arising from the over-determined scenario attendant to the application of four support positions is based on the fact that, as soon as a single actuator is activated, a certain disturbing parallel stiffness tends to arise as a result of deformation of the reference body. In activating one actuator, forces shall now be observed at all sensors, which forces are unintentionally associated with the reaction forces arising as a result of this torsional deformation of the reference body and not—as is desired—with the force to be detected by the sensors as a result of accelerative forces of the vibrations (that are to be damped) of the positioning means. This behavior, which is caused by parallel stiffness across said at least one combination of the series-positioned actuator and sensor, is also referred to using the technical term “crosstalk from actuator to sensor”. In the event of too great an amount of such (mechanical) crosstalk from actuator to sensor, the risk exists that it will be impossible from the point of view of control theory to continue to effectively damp vibrations with the aid of Smart Discs. To mitigate mechanical crosstalk, the control means preferably comprise first combining means for the purpose of combining at least a first input signal and a second input signal—from, respectively, at least a first sensor and a second sensor—into a first combined input signal, in dependence upon which the control means generate a first mutual control signal for the respective actuators associated with at least both the first sensor and the second sensor. Because, in this manner, input signals from a given sensor are not only of influence on the activity of the associated actuator, but also on that of the actuator associated with another sensor, one is able to achieve a scenario whereby the plane defined by the four support points remains more or less in correspondence with the plane of the reference body, as a result of which mechanical crosstalk diminishes and the reference body no longer deforms, or at least deforms to a markedly reduced extent. This advantageous effect can even be achieved if the first sensor and the second sensor are formed by a mutual sensor that, on the basis of an observed force, generates a mutual input signal for the control means, which signal is subsequently converted by the control means into the first mutual control signal. A similar effect, but acting in a different direction, can be obtained if the control means comprise second combining means for the purpose of combining at least the second input signal and a third input signal, from at least the second sensor and a third sensor, respectively, into a second combined input signal, in dependence upon which the control means generate a second mutual control signal for the respective actuators associated with at least the second sensor and the third sensor, whereby the control means comprise third combining means for the purpose of combining the first mutual control signal and the second mutual control signal into a combined mutual control signal for the second actuator. As a result of such a set-up, the activity of the second actuator will depend upon the input signals originating from the first, second and third sensor—in other words upon the forces exerted upon these sensors. Disturbing, undesired parallel stiffness arising from deformations of the reference body can thus also be prevented in the case of a second movement potential corresponding to a second degree of freedom of the reference body in a second direction. In this case also, however, one should once again note that, within the bounds of the invention, it is also possible to make use of a single mutual sensor instead of two sensors. A higher sensitivity of the employed actuators and sensors, leading to a more favorable signal-to-noise ratio, is obtained if the first combining means are embodied to combine at least the first input signal, the second input signal, a third input signal and a fourth input signal—from, respectively, at least the first sensor, the second sensor, a third sensor and a fourth sensor—into the first combined input signal, in dependence upon which the control means generate the first mutual control signal for the actuators respectively associated with the first sensor, the second sensor, the third sensor and the fourth sensor. A similarly advantageous effect is obtained in a second direction if the second combining means are embodied to combine at least the first input signal, the second input signal, the third input signal and the fourth input signal—from, respectively, at least the first sensor, the second sensor, the third sensor and the fourth sensor—into the second combined input signal, in a manner differing from the manner in which the first combining means combine the first input signal, the second input signal, the third input signal and the fourth input signal into the first combined input signal, in dependence upon which second combined input signal the control means generate the second mutual control signal for the actuators respectively associated with the first sensor, the second sensor, the third sensor and the fourth sensor. In general, it is noted that, where reference is made above to control signals, these control signals do not have to serve directly as input signals for the relevant actuators, but can also be further processed in a suitable manner, for example by combination (addition and/or subtraction, whether weighted or not) with other control signals, so as to arrive at an actual input signal for the actuators concerned. According to a very advantageous preferential embodiment of the invention, an intermediate body is provided between, on the one hand, the series-positioned actuator and sensor of said at least one combination, and, on the other hand, the reference body. In such a case, the series-positioned actuator and sensor of said at least one combination are provided between, on the one hand, the housing (or, more specifically, the support element thereof, and, on the other hand, the intermediate body. This markedly simplifies the assembly of the various parts of the device according to the invention, as a result of the fact that, in the first instance, the series-positioned actuator and sensor of said at least one combination can be correctly mounted before, in a later step, mounting the positioning means, which are usually characterized by great weight. Moreover, the intermediate body can form protection for delicate parts of said at least one combination. These advantages are also obtained if the intermediate body is applied between two (random) bodies, between which at least one combination of a piezo-electric sensor and actuator are applied. Both from the point of view of simplicity and of relatively small (bending) stiffness, the intermediate body is preferably plate-like, so that introduction of the intermediate body will not cause any undesired parallel stiffness. A highly suitable plate-like intermediate body is one that is made of aluminum and has a thickness smaller than 10% of the smallest principal dimension of the plate-like intermediate body. The term “principal dimension” should be construed in the case of rectangular plates as referring to the length and the breadth (whereby the breadth is naturally smaller than the length), or, in the case of, for example, a disc-like intermediate body, as referring to a diameter thereof, whereby it is assumed that the disc-like form is not necessarily round. For the purpose of fixing the series-positioned actuator and sensor of said at least one combination with respect to one another, it is advantageous if the intermediate body, parallel to said at least one combination, is connected to the housing before positioning said at least one combination between the intermediate body and the housing. If the intermediate body, parallel to said at least one combination, is connected to the housing before positioning of said at least one combination between the intermediate body and the housing, one obtains the possibility of still being able to displace the reference body with respect to the intermediate body, which is necessary in installing the device according to the invention so as to ensure that, in use, the object positioned by the positioning means, of which the reference body is part, is situated at the focus of the beam of particles. In the case of certain types of positioning means, one refers in this context to the eucentric axis of the positioning means, which is thus required to extend through the focus of the beam of particles. In order to adjust the relative positioning of, on the one hand, the reference body (and, accordingly, the positioning means), and, on the other hand, the housing, the device according to the invention is preferably provided with adjusting means, via which the reference body can be displaced in a direction parallel to the plate-like intermediate body. These adjusting means are preferably embodied so as to allow the reference body to be displaced in three degrees of freedom. A very suitable value of the force with which the reference body is supported against the intermediate body—which, moreover, allows the desired small displacement of the intermediate body with respect to the reference body—lies in the range between twice and twenty times the total weight of the positioning means that are to be supported. For the generation of such a force, spring means are preferably provided for the purpose of forcing the reference body and the intermediate body toward one another. Such spring means once again bring the attendant risk (already referred to earlier) of introducing undesired parallel stiffness across said at least one combination of the series-positioned actuator and sensor. Therefore, the stiffness of the employed spring means must be sufficiently low, whereby the following rule of thumb for the relationship between two eigenfrequencies preferably pertains:fspring<⅓fpos wherein fpos is the eigenfrequency (units: Hz) of the positioning means that, with the aid of the invention, it is sought to suppress, and fspring is the eigenfrequency of the imaginary system that would arise if the combined mass of the reference body plus the positioning means were to be supported on the spring means alone, i.e. in the absence of any combination or support element. This quantity fspring is accordingly simply dependent upon said stiffness (whose magnitude is to be curtailed) of the spring means, according to the relationship:fspring=½π√(c/m) whereby “c” is the stiffness of the spring means and “m” is the combined mass of the positioning means (including the reference body). According to a further particular preferential embodiment, each actuator is clamped between, respectively, a first actuator conducting body, in conducting contact with a first actuator pole of the actuator, and a second actuator conducting body, in conducting contact with a second actuator pole of the actuator, which first actuator conducting body and which second actuator conducting body are in conducting contact with the control means. The application of such actuator conducting bodies, between which the actuator is clamped, further simplifies the incorporation of said at least one combination in the device according to the invention during the manufacture thereof, particularly when the number of applied combinations is greater than one. A similar advantage is applicable if each sensor is clamped between, respectively, a first sensor conducting body, in conducting contact with a first sensor pole of the sensor, and a second sensor conducting body, in conducting contact with a second sensor pole of the sensor, which first sensor conducting body and which second sensor conducting body are in conducting contact with the control means. In the context of a possible simplified connection scheme of the various poles of the sensors and actuators, it is of further advantage if one of the two conducting bodies associated with the actuator or the sensor of a combination is provided with two contact points that are in conducting contact with both poles of the associated actuator or sensor. In this manner, connection of the control means to the poles of the actuators or sensors can occur via one conducting body, whereby the other conducting body is conductively connected to said one conducting body. So as to prevent, to the greatest extent possible, disturbing parallel stiffnesses from occurring across said at least one combination of actuator and sensor, it is preferable that the actuator with associated conducting bodies and/or the sensor with associated conducting bodies be provided with mutually connecting holes that collectively form a through-hole through which a traction organ extends for the purpose of clamping the actuator and/or the sensor, respectively, between the associated conducting bodies. The force with which the actuators and/or sensors are clamped between the associated conducting bodies should, in principle, be just sufficient to correctly position and hold the actuators, the sensors and the associated conducting bodies with respect to one another. A further improvement in this context is obtained if one of the four conducting bodies associated with the actuator and the sensor of a combination is provided with four contact points that are in conducting contact with both poles of both the actuator and the sensor. In this manner, a single multi-core cable can be used to connect every combination of an actuator and sensor to the control means, for the purpose of, on the one hand, sending input signals—being the input signals for the control means—from the sensors, and, on the other hand, sending control signals from the control means, resulting in input signals for the actuators. Also, with an eye to allowing the correct placement and connection of the combinations of actuators and sensors to proceed easily, it is preferable that the conducting bodies that are located between the actuator and the sensor of a combination be provided, at the sides facing one another, with contact points that are conductively connected to each other. A very advantageous embodiment of such conducting bodies, and thus of the device according to the invention, is obtained if at least a portion of the conducting bodies is provided—on at least one external surface—with at least one isolated conducting track for direct electrical contact either with a pole of an actuator or of a sensor or with a contact point or conducting track of a conducting body. Such tracks can render defunct the use of electrically conducting wire connections between conductive bodies mutually or between the conducting bodies and a pole of an actuator or sensor. According to a further preference, the conducting bodies associated with a combination of an actuator and a sensor are conductively connected to conducting organs that extend to outside the housing. Such conducting organs can, for example, be formed by electrically conducting cables. Because the conducting organs extend to outside the housing, the control means can also be provided outside the housing. FIG. 1 shows a manipulator 1 for application in the case of a scanning electron microscope. The manipulator 1 is made up of a base plate 2 and a manipulation unit 3. The base plate 2 has a length of approximately 300 mm and is connected to a portion of the housing of the scanning electron microscope in a manner that will be described later, particularly with reference to FIG. 2. The weight of the manipulator 1 is approximately 17 kg, whereby the weight of the separate manipulation unit 3 amounts to approximately 7 kg and the weight of the base plate 2 amounts to approximately 10 kg. The manipulation unit 3 can be displaced as a whole with respect to the base plate 2 along guides 4a, 4b in the direction of the double arrow 5 through a stroke of circa 150 mm. The manipulation unit 3 comprises a first displacement body 6, a swivel body 7, a second displacement body 8 and a sample holder 9. The first displacement body 6 is provided on opposite sides of the swivel body 7 with a bent guide, through which a portion of correspondingly formed, externally oriented guide ribs 10 of the swivel body 7 extend. Thanks to the co-operation between the guides (not further depicted) of the first displacement body 6 and the guide ribs 10a, 10b of the swivel body 7, it is possible to cause the swivel body 7, together with the second displacement body 8 and the sample holder 9, to swivel about the central axis of the bent/arch form of the relevant guides and guide ribs 10a, 10b, through an angular range of circa 60 degrees. Perpendicular to said central axis, the swivel body 7 is provided with a pair of guide bodies 11a, 11b on opposite sides of the second displacement body 8, for guided co-operation with guide organs (not further depicted) of the second displacement body 8 that are directed toward the guide bodies 11a, 11b. In this manner, translation of the second displacement body 8 with the sample holder 9 is made possible in the longitudinal direction of the guide bodies 11a, 11b, through a stroke of circa 150 mm. The sample holder, which has a disc-like form, can be rotated through a number of complete revolutions about its own central axis, and can also be adjusted in height through circa 30 mm perpendicular to the plane of the disc-like form. The sample holder is suitable for holding samples which are destined for further study with the scanning electron microscope concerned. Thanks to all guides as described above, it is possible to manipulate the sample in a total of five degrees of freedom, so as to optimally position and orient the sample in the focus of the electron ray that is generated in the scanning electron microscope. Manipulators of the type of manipulator 1 are known to the skilled artisan, and a detailed description thereof is not necessary in the context of the present invention. On the basis of FIG. 2, it will be further elucidated how, during manufacture of the scanning electron microscope, manipulator 1 is incorporated with the housing of the scanning electron microscope. In this context, it is noted that FIG. 2 is schematic in nature. FIG. 2 only depicts the base plate 2 of manipulator 1. This base plate 2 is provided at the corner points on its underside with square feet 13a, 13b, 13c, 13d. Near the corner points, bores 14a, 14b, 14c, 14d are present beside the feet 13a, 13b, 13c, 13d. Near the feet 13b and 13c, in the side face 15 of the base plate 2, two horizontally oriented screw-threaded shafts 16a, 16b have been created. In the rearmost side surface 17 (as depicted in FIG. 2) of base plate 2, a further horizontally oriented screw-threaded shaft 16c has been created close to foot 13c. Directly above the extremities of these screw-threaded shafts 16a, 16b, 16c, in the upper surface 18 of base plate 2, vertical screw-threaded shafts have been provided, which emerge into the screw-threaded shafts 16a, 16b, 16c and through which securing screws 18a, 18b, 18c extend for securing screw bodies that extend within the screw-threaded shafts 16a, 16b, 16c. Of the housing of the scanning electron microscope, only a basin-like portion 19 is depicted in FIG. 2, which portion surrounds the side surfaces and underside of the base plate 2 in the assembled state. As an aside, it is noted that the housing of the scanning electron microscope does not have to be embodied as a single integral part, but that it can also be made up of a number of rigidly mutually connected components. In that context, it would be permissible, within the bounds of the invention, if the basin-like portion 19, or at least the base 20 thereof, were a part that was rigidly connected to the remaining portion of the housing. On the base 20, square raised portions 21a, 21b, 21c, 21d are provided, which are mutually positioned so as to correspond to feet 13a, 13b, 13c, 13d of base plate 2. Vertical screw-threaded shafts 22a, 22b, 22c, 22d are provided centrally in the square raised portions 21a, 21b, 21c, 21d. On each of the four raised portions 21a, 21b, 21c, 21d is located a stack 23 of a lower printed circuit board disc 24, a disc-like piezo-electric actuator 25 and an upper printed circuit board disc 26. These disc-like bodies 24, 25, 25 are provided in their middles with a through hole, through which a vacuum-compatible screw 27 extends, whose head 28 is sunk into the upper printed circuit board disc 26. The screw 27 is turned inside the screw-threaded shaft associated with the relevant raised portion, as a result of which, to a limited extent, a clamping force exists between the lower printed circuit board disc 24, the piezo-electric actuator 25 and the upper printed circuit board disc 26. For the purpose of correctly centering the piezo-electric actuator 25, a further centering body 29 is provided in the central hole thereof. In a more or less equivalent manner, a second stack 30 is furnished at each of the first stacks 23, against the undersurface of a coupling plate 31 that is present between the base plate 2 and the base 20. This coupling plate 31 is provided at its corner points with holes 32a, 32b, 32c (32d is not visible in FIG. 2). The second stack 30 consists of a lower printed circuit board disc 34, a piezo-electric sensor 35 and an upper printed circuit board disc 36. These disc-like bodies 34, 35, 36 are clamped against one another by means of a screw 33, which extends through central holes in these disc-like bodies as well as through the relevant hole 32a, 32b, 32c, 32d. Clamping occurs as a result of tightening nut 37 on the upper side of coupling plate 31. So as to accommodate the extremity of the screw thread of the screw 33, and that of nut 37, cavities 38 are provided on the underside of feet 13a, 13b, 13c, 13d. So as to allow correct centering of the piezo-electric sensor 35, a centering body 39 is provided in the hole of the piezo-electric sensor 35. The head 40 of screw 33 is sunk into the lower printed circuit board disc 34. Around the middle of base 20, three raised portions 41a, 41b, 41c are provided. The height of these raised portions 41a, 41b, 41c is equal to the sum of the raised portions 21a, 21b, 21c, 21d, one stack 23 and one stack 30, so that the upper face of the raised portions 41a, 41b, 41c is substantially at the same vertical level as the upper surface of the four upper printed circuit board discs 36. The function of the various printed circuit board discs and the piezo-electric sensors and actuators will be further elucidated later on. Assembly proceeds as follows. In the first instance, the stacks 23 are clamped to the raised portions 21a, 21b, 21c, 21d by tightening the screws 27 in the associated screw-threaded shafts 22a, 22b, 22c, 22d. The tightening force applied hereby in the case of the screws 27 principally serves to correctly and permanently position the various parts of the stack 23 with respect to one another. Stacks 30 are clamped against the undersurface of the coupling plate 31 by application of screw/nut combinations 33, 37. Subsequently, coupling plate 31 is screwed onto the upper faces of raised portions 41a, 41b, 41c by tightening screws 43a, 43b, 43c in screw-threaded shafts 42a, 42b, 42c in the upper faces of raised portions 41a, 41b, 41c. To this end, three holes 44 are provided around the center of coupling plate 31, which are mutually positioned so as to correspond to the raised portions 41a, 41b, 41c. In a subsequent phase of the assembly process, manipulator 1 is placed on coupling plate 31, whereby the nuts 37 and the extremities of screws 33 extend—with a certain amount of sideways play—within the cavities 38 of the various feet 13a, 13b, 13c, 13d. For the purpose of ensuring that base plate 2 is not supported on only three feet 22a, 22b, 22c, 22d but, instead, on all four feet—as a result of which a desired statically over-determined support situation is achieved at four points of the base plate 2 on the base 20—one of the feet 13a, 13b, 13c, 13d is adjustable in height, in a manner not further depicted, whereby adjustment in height occurs, if necessary, after the base plate 2 has been placed on the coupling plate 31. In this manner, the base plate 2 of the manipulator 1 is positioned in such a manner that bores 14a, 14b, 14c, 14d extend more or less directly above holes 47a, 47b, 47c (47d is not visible) in coupling plate 31 and above screw-threaded shafts 45a, 45b, 45c, 45d in base 20. Thanks to this aligned positioning, it is possible for screw-threaded bodies 46—with a radial play of the order of approximately 1 to 2 mm—to extend through mutually associated bores 14a, 14b, 14c, 14d, holes 47a, 47b, 47c, 47d and screw-threaded shafts 45a, 45b, 45c, 45d. The undermost extremities of the screw-threaded bodies 46 are hereby screwed tight into the screw-threaded shafts 45a, 45b, 45c, 45d. Around the upper extremity of each screw-threaded body 46, a pressing spring 48 and a washer 49 are fitted. Subsequently, a nut 50 is tightened onto the upper extremity of the screw-threaded body 46, so that pressing spring 48 is pre-loaded and the four pressing springs 48 together press the base plate 2 downward with a force of the order of circa 600 N, supplemental to the gravitational force that is already exercised downwards as a result of the weight of the manipulator 1. As described earlier, the stiffness of the pressing spring 48 must not be too large, so as to avoid an undesired parallel stiffness across the stacks 23 and 30. A rule of thumb for determining an acceptable stiffness of the pressing spring 48 has already been given, whereby it should be noted that a typical eigenfrequency of the resonance (that is to be suppressed) of the manipulator 1 lies in the range between 75 and 1000 Hz. In this manner, one also achieves a situation whereby the stacks 23 and 30—or, more specifically, the upper face of the upper printed circuit board disc 26 and the lower face of the lower printed circuit board disc 34—are pressed against one another in good electrical contact. In this context, one should realize that the bending stiffness of coupling plate 31 is relatively small, as a result of the limited thickness thereof (circa 1 mm) and also the mechanical properties of the aluminum from which the coupling plate 31 is manufactured. Coupling plate 31 can, therefore, categorically not be considered as being stiff in the direction perpendicular to the plate plane of the coupling plate 31, and shall therefore not introduce any worrying parallel stiffness. As a result of its plate-like form, the coupling plate 31 is, however, stiff in the directions parallel to the plate plane of the coupling plate 31, which is of importance in bearing the sideways forces that arise as a result of displacing the base plate 2 over the coupling plate 31 in the horizontal direction, as will be further described hereunder. The size of the downward force produced by the pressing springs 48 and the gravitational force associated with manipulator 1 is not so large as to render no longer possible a small horizontal displacement of the manipulator 1—or, more specifically, the base plate 2 thereof—by exercising a sideways force. Such a displacement is necessary in order to ensure that the manipulator 1—or, more specifically, the central axis of the arch-like guide ribs 10a and 10b, about which the swivel body 7 can swivel—is correctly positioned with respect to the electron beam that is generated in the case of the scanning electron microscope. So as to be able to correctly perform this positioning, it is necessary that manipulator 1 be brought into a vacuum environment, as a result of which it is possible to generate an electron beam, whereby this electron beam is subsequently employed in observing what the exact position and orientation of the manipulator 1 are. For the purpose of displacing the manipulator 1 in three degrees of freedom while it is located within the housing of the scanning electron microscope, in vacuum, two screw-thread casings 52, 53 are provided in side face 51, through which casings an adjusting organ 54 extends. The adjusting organ comprises an engagement portion 140 at whose extremity is located a screw-thread portion 55 intended to engage in screw-threaded shafts 16a, 16b. Located in this screw-thread portion 55 is a securing hole 56 in which the respective extremities of securing screws 18a, 18b, 18c can engage, so as to secure the adjusting organ 54 in a prescribed rotational position. Located directly behind screw-thread portion 55 is a flat bending part 57, which ensures that the bending stiffness of the adjusting organ 54 is limited, at least in the direction parallel to the base 20. This flat part 57 is located between the aforementioned screw-thread portion 55 and a further screw-thread portion 58 of the engagement portion 140 that extends within an adjustment bushing 59 of the adjusting organ 54, which is provided around its central axis with an internal screw thread that co-operates with the further screw-thread portion 58. Adjusting bushing 59 is provided at one extremity with a screw thread 60 on its outside and at the other extremity with a sealing ring 61. Sealing ring 61 ensures that, despite the penetration of adjusting organ 54 through side face 51, the vacuum existing within the housing does not get interrupted. Screw thread 60 is destined for engagement co-operation with the internal screw threads of screw-thread casings 52, 53. The speed of screw thread 60, and therefore of the screw thread of the screw-thread casings 52, 53, is chosen so as to be greater than the speed of the further screw-thread portion 58 and the internal screw thread (not further depicted) in adjustment bushing 59. In this manner, a certain transfer ratio is realized, as a result of which turning the adjustment bushing 59 in the screw-thread casings 52, 53 leads to a very small longitudinal displacement of the screw-thread portion 55, and thus of the base plate 2 and the manipulator 1. A similar manner in which to adjust base plate 2 is also available at the location of screw-thread casing 62, which is provided on the outside of side face 63 in FIG. 2 at the rear side of the basin-like portion 19 of the housing, to which end screw-threaded shaft 16c is also provided. In this manner, it is possible to correctly position manipulator 1—in vacuum, in three degrees of freedom in the plane parallel to the base 20—with respect to the electron beam of the scanning electron microscope. As soon as the correct position is achieved, the three adjusting organs 54 are secured in a manner that is not further depicted, so that the position of the manipulator 1 within the housing of the scanning electron microscope is also fixed. The various disc-like parts of stacks 23 and 30 are respectively depicted in FIGS. 4 to 9 and 10 to 15. Stack 30 comprises a piezo-electric sensor 35 in its middle. This sensor is able to measure forces. These forces result in a potential difference between the upper face 64 and the lower face 65 of the sensor 35, which is provided on its upper face 64 and lower face 65 with an evaporated silver layer for electrical contact purposes, so that upper face 64 and lower face 65 can accordingly be regarded as poles. The magnitude of this potential difference is a measure of the magnitude of the force or, with a more specific eye to vibrations of the manipulation unit 3, the temporal changes in force exerted on the sensor 35. For the purpose of measuring the potential difference, the upper printed circuit board disc 36 and the lower printed circuit board disc 34 are respectively provided at the upper face 64 and the lower face 65 of the sensor 35. The upper printed circuit board disc 36 is provided on its lower face with a ring-like conducting track 66 that lies against the upper face 64 of sensor 35. As is visible in FIG. 13, a protruding part 67 connects to the ring-like track 66, which part 67 extends to outside the perimeter of sensor 35. In the event of good conducting contact between the upper face 64 of sensor 35 and track 66 of the upper printed circuit board disc 36, the potential level at upper face 64 will correspond to the potential level at the location of contact point 68 on the protruding part 67. The lower printed circuit board disc is also provided with a ring-like track 69, to which connects a protruding part 70 with contact point 71. In addition, on the outside of the upper face of the lower printed circuit board disc 34, a small track region 72 is provided, which is isolated from track 69 and which extends outside the external diameter of sensor 35. The contact point 73 is connected via an electrically conducting wire 74 to contact point 68 of the upper printed circuit board disc 36, so that contact point 73 will ultimately assume the same potential level as that of upper face 64 of sensor 35. Because of the fact that ring-like track 69 lies against the lower face 65 of sensor 35, contact point 71 will assume the same potential value as that of the lower face 65 of sensor 35. The lower face of the lower printed circuit board disc 34 is provided with two conducting tracks that are isolated from one another. One of the tracks comprises a ring-like portion 75 to which connects a protruding part 76 with contact point 77. The other track comprises an interrupted ring-like portion 78 that substantially surrounds ring-like portion 75, and is also provided with a protruding part 79 with a contact point 80. The contact points 71 and 80 are connected to each other right across the main body of the lower printed circuit board disc 34 via a conducting connection 81 (FIG. 12). A similar sort of connection is realized between the contact points 73 and 77. All of this results in a situation whereby the potential level of contact point 80 corresponds to that of the lower face 65 of sensor 35, while the potential level of contact point 77 corresponds to that of the upper face 64 of sensor 35, so that the potential difference between contact points 77 and 80 is a measure of the force that is exerted on the sensor. A piezo-electric actuator 25 is centrally provided in stack 23. Such an actuator is able to expand and/or contract in the height direction in reaction to the application of a potential difference between the upper face 82 and the lower face 83 of actuator 25, which faces 82, 83 can be regarded as poles. In combination with a piezo-electric sensor, such as sensor 35, which is connected in series with actuator 83, it is thus possible to realize an active damping system. In this scenario, the potential difference between upper face 64 and lower face 65 of piezo-electric sensor 35 (which potential difference is a measure of the force that is exerted on this sensor) is passed on to a control system that processes this potential difference as an input signal and produces an output signal for the actuator 83, which, in reaction hereto, shall alter its height. In this fashion, it is possible to very suitably damp vibrations that, for example, arise as a result of sound waves acting on the housing of the scanning electron microscope, which might tend to cause the manipulation unit 3 to vibrate, as a result of which the required positional accuracy and stability of a sample with respect to the electron beam would not be achieved to a sufficient extent. For the purpose of applying a potential difference between the upper face 82 and the lower face 83 of actuator 25, an upper printed circuit board disc 26 and a lower printed circuit board disc 24 are provided on opposite sides. This lower printed circuit board disc 24 is provided on its upper face with a ring-like track 84 with protruding part 85 on which a contact point 86 is located. The upper printed circuit board disc 26 is provided on its lower face with a ring-like track 87 to which connects a protruding part 88 on which a contact point 89 is provided. In addition to this, a small track region 90, which is isolated from ring-like track 87, is located on the lower face of the upper printed circuit board disc 26. The track region 90 comprises a contact point 91. The track region 90 is located outside the outer perimeter of actuator 25. The upper face of the upper printed circuit board disc 26 is provided with two track regions 92, 93 on which respective contact points 94, 95 are located. In addition to this, two mutually isolated tracks are provided, one of which comprises a ring-like track portion 96 to which connects a protruding part 97 with a contact point 98, and the other of which comprises an interrupted ring-like track portion 99 that substantially surrounds ring-like track portion 96 and is provided with a protruding part 100 with contact point 101. During use, the ring-like track 96 with the protruding part 97 lies against the ring-like track 75 and the protruding part 76, respectively, as a result of which contact point 98 assumes the same potential level as that of the lower face of sensor 35. In a similar fashion, the potential level of contact point 101 assumes the same value as that of the upper face 64 of sensor 35. Contact points 86 and 91 are connected to one another via electrically conducting wire 102. By means of a connection comparable to connection 81, contact point 91 is connected to contact point 94. In this manner, the potential level of contact point 94 is equal to that of the lower surface 83 of actuator 25. Contact points 89 and 95 are also connected to one another by means of a connection similar to connection 81, so that the potential level of contact point 95 corresponds to that of the upper face 82 of actuator 25. In this manner, all relevant potential levels of the actuator and the sensor are available on the upper face of the upper printed circuit board disc 26, which enables very simple installation and simple connection possibilities for the actuator 25 and the sensor 35 via electrically conducting wire. To this end, a four-core cable 103 is provided with cores 104, 105, 106, 107 and a vacuum-compatible cladding 108. Running—through a single cladding and in close proximity to one another—the two cores 104 and 105 according to the description pertaining to the sensor 35 and the two cores 106 and 107 according to the description pertaining to the actuator 25 incurs the attendant risk of a certain degree of electrical coupling between actuator and sensor. Similar to the aforementioned mechanical crosstalk, it is possible that activation of one actuator by applying a potential difference between cores 106 and 107 may cause a small potential difference to arise between cores 104 and 105, as a result of which an unintended force is observed on the sensor 35, which force is unintentionally directly related to the potential difference applied between the cores 106 and 107, and not, as intended, to a force to be observed by the sensor 65 due to accelerative forces of the vibrations (that are to be damped) in manipulation unit 3. To avoid this effect—which is referred to in technical terms as “electrical crosstalk”—to as great an extent as possible, the two cores 104 and 105 are together preferably fed through the cladding 108 within an electrical cladding (not further depicted) that, at one of the extremities of cladding 108, is electrically connected to a suitable electrical reference contact point for the whole electrical system—a so-called “electrical earth point”. In the same manner, the two cores 106 and 107 are together preferably fed through the cladding 108 within a similar electrical cladding (not further depicted) that, in a similar fashion, is connected to a suitable electrical earth point. As is visible in FIG. 2, cable 103 is fed through side wall 51 in a gastight manner. As an alternative, it is also possible to make use of a plug system for this purpose. Outside the housing of the scanning electron microscope, there is a control system (not further depicted) that is capable of processing an output signal from the sensor 35—in the form of a potential difference between cores 104 and 105—and producing an output signal for the actuator 25—in the form of a potential difference between the cores 106 and 107—for the purpose of actively mitigating vibration of the manipulation unit 3. As an aside, it is noted that, in the description of the embodiment, the function of actuator allotted to the lower stack 23 and the function of sensor allotted to the upper stack 30 are not limiting. Both functions are, in principle, completely exchangeable, so that the function of sensor can also be allotted to the lower stack 23 and the function of actuator can also be allotted to the upper stack 30. So as to achieve correct positioning of the individual parts of the stacks 23 and 30 with respect to one another, it is also possible to provide these parts with a non-round form, as a result of which it is easy to have these parts assume the correct angular orientation with respect to one another. In principle, vibrations shall occur in two essentially mutually perpendicular principal directions perpendicular to the direction of the normal to the sample holder 9, as a result of the position and orientation of the guides applied in the case of the manipulation unit 3. It is possible to actively oppose these vibrations by only activating each of the four applied actuators 25 via a control unit in sole dependence upon the output signal that the sensor associated with the relevant actuator passes to the control unit. An important disadvantage of such a method of damping—in which, consistently, only one single combination of actuator 25 and sensor 35 co-operates with one control unit—is that a disadvantageous torsional deformation of the base plate 2 is unavoidable. Seeing as the four actuators 25 are provided at the corner points of the base plate 2, it is impossible in the case of independent operation of the four actuators 25 that the base plate 2 remain as a perfectly flat plate; instead, this shall be torsionally loaded, and accordingly deformed, as a result of which the accuracy with which the manipulator 1 can position a sample will also ultimately be disadvantageously influenced. Moreover, when one actuator 25 is activated, forces will now be observed on all four of the sensors 35, which forces are unintentionally related to the reaction forces occurring as a result of the torsional deformation of the base plate 2 and not, as intended, to the force to be observed by the sensors 35 as caused by accelerative forces of the vibrations (to be damped) of the manipulator unit 3. This behavior, which is caused by parallel stiffness across all four combinations of series-positioned actuator 25 and sensor 35, is also referred to using the technical term “crosstalk from actuator to sensor”. In the case of an excessive degree of this (mechanical) crosstalk from actuator to sensor, the risk arises that, as far as control theory is concerned, it will become impossible to continue to effectively damp vibrations with the aid of Smart Discs. A logical solution to this problem would seem to reside in the application of only three combinations of actuators 25 and sensors 35. Such a means of supporting the base plate 2 at three points is called “statically determined”, while supporting at four (or more) points is essentially statically over-determined. As a consequence of supporting the base plate 2 at three points in a statically determined fashion, the independent activation of three actuators 25 logically cannot lead to (torsional) deformation of the base plate 2, seeing as the base plate in its flat state—without being torsionally loaded—can direct itself to the (very small) damping motions of the three actuators 25, as a result of which it will only become tilted to a (very small) extent. Practically speaking, however, such a scenario of statically determined support of the base plate 2 at just three points has the considerable disadvantage that a torsional deformation of the base plate 2 is now, in fact, freely possible, and is only limited by the internal torsional stiffness of the base plate 2 itself, without being further impeded by the presence of a fourth support. The great risk here (i.e. the statically determined support of the base plate 2 at just three points) is that the torsional stiffness of this torsionally limp base plate 2 would now determine the first (i.e. the lowest) eigenfrequency—and the vibrational form associated therewith—of the manipulator as a whole, rather than, as desired, principally the manipulation unit 3, if support were to occur—via a parallel guide that, in practice, did not determine the eigenfrequency and via the base plate 2—at four points (i.e. in a statically over-determined manner). In addition, the first (i.e. lowest) eigenfrequency of the dynamic system demonstrating the perturbing vibrations will be much lower in value if the base plate 2 is supported at three points than if the base plate is supported at four points. In general, in an initial situation, i.e. before any control unit is rendered effective for any combination of sensor 35 and actuator 25, a lower first eigenfrequency of the dynamic system demonstrating the perturbing vibrations will lead to markedly greater amplitudes of the vibrations as a result of excitation via acoustic environmental noise or floor vibrations. Consequently, the final amplitude of the vibrations subsequent to optimal damping of the vibrations—after one or more control units are made effective—will always be smaller if the value of the first eigenfrequency of the dynamic system demonstrating the perturbing vibrations is as high as possible to start off with. Accordingly, the described statically over-determined method of supporting the base plate 2 at four points is highly preferential. In order to achieve this desired statically over-determined method of support during assembly, it is accordingly necessary—as already described above—that one of the feet 13a, 13b, 13c or 13d be adjustable in height in a manner not further elucidated. In the present preferential embodiment of the invention, the disadvantage of mechanical crosstalk from actuator to sensor as described above, which is the unavoidable consequence of the highly desired over-determined support at four points, is overcome in the case of using four combinations of actuators 25 and sensors 35 by arranging that each, or at least a portion, of the four actuators 25 not be rendered active in dependence upon only the output signal emitted and passed to the control unit by the sensor 35 associated with the actuator 25 concerned, but rather in dependence upon the (sum of) the output signals of at least two sensors. In this manner, the possibility arises of matching the activation of the sensors 25 to one another, so that, despite the fact that there are four support points for the base plate 2, the base plate 2 will not be torsionally loaded and, accordingly, will not deform. Various aspects of the above will be elucidated on the basis of FIG. 16. FIG. 16 renders a highly schematic plan view of base plate 2. Black dots indicate the four combinations of actuators 25 and sensors 35 at the corner points. In addition, FIG. 16 indicates the rough location of the center of gravity 109 of the manipulation unit 3, around which two curved arrows 110, 111 symbolize the two mutually perpendicular principal directions of vibration. The output signals of the sensors 35—which, as already mentioned, are a measure of the force registered by the sensors 35—are respectively indicated by S1, S2, S3 and S4. The input signals to the respective actuators 25 are indicated by A1, A2, A3 and A4. The associated control system comprises three combination units 112, 113, 114, each of which generates a single output signal by adding together two incoming signals. In addition, the control system comprises two control units 115, 116, which process incoming signals according to a given frequency-dependent characteristic (referred to as “controller transfer”) and amplification factor (referred to as “gain”) so as to produce output signals. In practice, such control units can be embodied as an analog electronic circuit, or as a digital computer. The output signals S1 and S2 are added by combination unit 112, resulting in an output signal SX that functions as an input signal for control unit 115. In a similar manner, the output signals S2 and S3 are added by combination unit 113, resulting in an output signal SY that functions as an input signal for control unit 116. The input signals SX and SY are processed by the respective control units 115, 116 to produce respective output signals AX and AY. These signals AX and AY are employed as input signals A1 and A3 for the actuators 25 respectively associated with the first combination and the third combination of an actuator 25 and a sensor 35. The signals AX and AY are further added by combination unit 114, resulting in an input signal A2 for the actuator 25 of the second combination. In this manner, each input signal A1, A2, A3 for an actuator 25 is dependent on the force that is measured by the associated sensor 35 as well as that measured by a neighboring sensor 35. It is of importance to note that the actuator 25 and sensor 35 of the fourth combination as a whole remain unused. In the present preferential embodiment, this fourth combination could accordingly be replaced by a passive mechanical support point. The force that is measured by the sensor 35 of the second combination, which is located opposite the fourth combination, is, in contrast, employed so as to influence the activity of the actuators 25 of the first, second and third combination. In addition to this, the activity of the sensor 25 of the second combination is dependent upon the forces that are measured by all three sensors 35 of the first, second and third combination. Combining the various signals as described above on the basis of FIG. 16 results in a situation whereby vibrations according to arrow 110 are damped as a result of the action of the actuators 25 of the first and second combination, whereby the base plate 2 swivels about a swivel axis 117 that extends through the support points of base plate 2 at the location of the third and fourth combination. Vibrations according to arrow 111 will be damped as a result of the action of the actuators 25 of the second and third combination, whereby the base plate 2 swivels about a swivel axis 118 that extends through support points of base plate 2 at the location of the first and fourth combination. Due to these swivel axes 117, 118, the base plate 2 will not be torsionally loaded, so that the various sensors 35 will not register any perturbing forces resulting herefrom. The base plate 2 will accordingly remain flat. An alternative control system that can be advantageous with an eye to symmetry, and that allows a higher sensitivity of the applied actuators and sensors to be achieved, leading to a more favorable signal-to-noise ratio, is schematically depicted in FIGS. 17, 18. In this control system, the fourth combination of an actuator 25 and sensor 35 is actually applied. As can be derived from FIG. 17: combination unit 119 generates signal S1+2 on the basis of output signals S1 and S2; combination unit 120 generates signal S2+3 on the basis of output signals S2 and S3; combination unit 121 generates signal S3+4 on the basis of output signals S3 and S4, and combination unit 122 generates signal S4+1 on the basis of output signals S4 and S1. On the basis of (the difference between) signals S1+2 and S3+4, combination unit 123 generates signal SX, whereas, on the basis of (the difference between) signals S2+3 and S4+1, combination unit 124 generates signal SY. The signals SX and SY are processed by respective control units 125, 126 to produce signals AX and AY (FIG. 18). On the basis of (the difference between) the signals AX and AY, combination unit 127 generates control signal A1 for the actuator 25 of the first combination. On the basis of (the sum of) the signals AX and AY, combination unit 128 generates control signal A2 for the actuator 25 of the second combination. On the basis of (the difference between) the signals AY and AX, combination unit 129 generates control signal A3 for the actuator 25 of the third combination. Finally, on the basis of (the negative sum of) the signals AX and AY, combination unit 130 generates control signal A4 for the actuator 25 of the fourth combination. In the case of a control system operating in this manner, each control signal A1, A2, A3, A4 is dependent upon the forces that are measured by each sensor 35 of the four combinations. Vibrations according to arrow 110 are damped by the activity of all four actuators 25, whereby, on the one hand, the actuators 25 of the first and second combination, and, on the other hand, the actuators 25 of the third and fourth combination, will act in pairs in an inverted manner, as a result of which swiveling of the base plate 2 about the swivel axis 131 will occur. In a similar manner, vibrations according to arrow 111 are damped by the activity of all four actuators 25, whereby, on the one hand, the actuators 25 of the first and fourth combination, and, on the other hand, the actuators 25 of the second and third combination, will act in pairs in an inverted manner, as a result of which swiveling of the base plate 2 about the swivel axis 132 will occur. Swivel axes 131 and 132 correspond to the middle lines of base plate 2. Swiveling action of base plate 2 about these swivel axes 131, 132 will not result in plate 2 being torsionally loaded and disturbingly deformed. It will be clear to the expert reader that control systems in all sorts of different forms can be applied within the bounds of the invention. For example, it is possible to displace the location of the swivel axes of the manipulation unit 3—possibly in dependence upon their momentary position with respect to the degrees of freedom—by assigning different weights to the input signals in the case of the employed combination units. In this manner, one can, for example, manipulate the point of intersection of the swivel axes so as to be roughly directly underneath the center of gravity 109 of the manipulation unit 3 in every position of the sample holder 9. A rotation of the swivel axes can even be achieved in this manner. In the case of such a strategy, the exact form of the control system is thus actually made dependent upon one or more parameters of the whole system (for example, the position of the sample holder 9).
040177378	abstract	A conveyor apparatus, such as a cart, is disclosed, for aiding in the placement of subjects to be x-rayed in position in a radiographic apparatus. The conveyor apparatus includes a conveyor belt on which a patient is placed and a mechanical linkage having a mechanical advantage connecting the conveyor belt to an operator, so that relatively small movement of the operator causes relatively large movement of the patient carrying conveyor belt.
051125714	abstract	In a fuel assembly having fuel rods inserted into regularly arranged cells of a fuel spacer which keeps the fuel rods correctly spaced from one another and has spacer elements disposed in a plurality of stages in the longitudinal direction of the fuel rods, the fuel spacer comprises vanes formed on the cells in such a manner that each vane is bent from a cut formed in a part of the side wall of the cell. The vanes obliquely project into the corresponding spaces between adjacent fuel rods and allow a coolant flowing through the spaces and forming two-phase flows to generate swirling flows toward the fuel rods. The fuel spacer may alternatively comprise either thin-walled cylinders having built-in vanes or spiral vanes, which are fixed to the spacer that has not been subjected to any direct machining. Also disclosed is a fuel assembly provided with any of the above-described fuel spacers. The arrangement of the present invention enables, while assuring a sufficient strength for maintaining fuel rods in their correct position, the transfer of heat from the fuel rods to the coolant to be promoted so as to raise the allowable power level of the fuel assembly, and enables the void ratio to be lowered so as to increase the reactivity.
	abstract	A zirconium alloy tube for forming the whole or the outer portion of a nuclear fuel pencil housing or a nuclear fuel assembly guide tube. The zirconium alloy contains 0.8-1.8 wt. % of niobium, 0.2-0.6 wt. % of tin and 0.02-0.4 wt. % of iron, and has a carbon content of 30-180 ppm, a silicon content of 10-120 ppm and an oxygen content of 600-1800 ppm. The tube may be used when recrystallized or stress relieved.
	summary
	description	This invention was made with Government support under Contract DE-AC0576RLO1830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention. 1. Field of the Invention The invention generally relates to methods and systems for the generation of radioisotope products and in one embodiment to the generation of technetium-99m. 2. Background Information Technetium-99m (Tc-99m), the radioisotope most widely used in nuclear medicine diagnostic procedures, is used in the detection of cancer, heart disease and thyroid disease, along with the study of brain and kidney function and the imaging of stress fractures. Over the past two decades, the nuclear medicine industry has experienced intermittent shortages of molybdenum-99 (Mo-99), the parent of Tc-99m as a result of unplanned reactor outages. The world's supply of medical Mo-99 is primarily produced by five aging reactors in Canada, Europe, and South Africa, and at present no strategy exists to provide a global, long-term reliable supply of Mo-99. In addition, in the interest of nuclear security and non-proliferation, the U.S. and other countries are increasing the pressure to migrate the industry from using customary Highly Enriched Uranium (HEU) to Low Enriched Uranium (LEU) for the production of Mo-99. There are a variety of available Mo99 production methods including U235(n,f)Mo99, U238(γ,f)Mo99, Mo98(n,γ)Mo99, and Mo100(γ,n)Mo99. A National Academy of Sciences study commissioned in 2009 recommended the irradiation of LEU in a fission reactor to produce Mo-99 where separation of Mo from the plurality of uranium fission products and actinides continues to be required to obtain high specific activity Mo-99. This makes the “fission product” Mo method economically challenging in view of the dedicated specialized radiochemical facilities and equipment and the increasing regulatory demands associated with uranium target manufacturing and the handling, storing, and disposing of the nuclear waste from fissioned uranium. There is a need for a more economical method to produce Tc-99m from Mo-99. Producing Mo99 from natural or isotope-enriched Mo targets has the main advantage of eliminating the need for dedicated radiochemical facilities (hot cells) while producing nearly no waste stream compared with the fission product approach. For example, Mo99 produced from neutron capture of natural Mo (containing about 24% Mo98) provides certain advantages and is discussed herein in relationship to the invention (it is understood that the invention is not limited to such production mode of Mo99). There are two disadvantages to using Mo99 derived from neutron capture of natural molybdenum for Tc-99m generation. First, the low specific activity of such “neutron-capture” Mo-99 (i.e., number of curies of Mo99 per gram of Mo) typically requires very large Tc-99m generators and elution volumes when compared to conventional alumina generators using fission product Mo-99. Second, the separation of Tc-99m from the parent Mo-99 in a compact generator requires high selectivity (USP guidelines indicate that there must be less than 0.15 microcuries of Mo99 per millicurie of Tc-99m and no more than 10 micrograms of aluminum ion per milliliter of generator eluate). No effective ion exchange technology currently exists that provides sufficiently effective selective capture so as to enable high capacity sorption of Mo-99-containing molybdenum, while simultaneously providing the selective separation of the Tc-99m decay product from the molybdenum in those cases where the Mo-99 has low specific activity. What is needed therefore is a device and methodology for selective generation of daughter radioisotope products from parent materials that has sufficient specificity so as to allow for lower specific activity parent materials to be utilized. The present invention is a significant advancement in this regard. The present invention is a system and a process for producing selected isotopic daughter products from parent materials characterized by the steps of loading the parent material upon a sorbent having a functional group configured to selectively bind the parent material under designated conditions, generating the selected isotopic daughter products, and eluting said selected isotopic daughter products from the sorbent. In one embodiment, the process also includes the step of passing an eluent formed by the elution step through a second sorbent material that is configured to remove a preselected material from said eluent. In some applications a passage of the material through a third sorbent material after passage through the second sorbent material is also performed. In one embodiment of the invention, the present invention is a process for generating Tc-99m and a system for carrying out such a process which includes dissolving Mo-99-containing molybdenum in a loading solution; and contacting the loading solution with preselected ion exchange material having a greater affinity for molybdate ion than technetium whereby the Mo-99 attaches to the ion exchange material, decays to Tc-99m and detaches from the ion exchange material to produce pertechnetate. The undecayed Mo-99 remains attached to the ion exchange material. The Mo-99-containing molybdenum can be produced through neutron capture of naturally occurring or enriched Mo98 to obtain a specific activity greater than 100 millicurie Mo99/gram of molybdenum. (MNCP calculations indicated a 1MW TRIGA reactor can achieve ˜420 millicurie Mo99/gm after 144 hours of exposure. Seventy two hours provides almost 300 millicurie). The Tc-99m produced from the generator may be subsequently treated by various means to form labeled Tc99m complexes. In one embodiment of the invention the preselected ion-exchange material is a silica based ion exchange material, built on a nanoporous silica support having a surface area greater than 400 m2/g. Preferably, the pre-selected ion exchange material is a Self-Assembled Monolayers on Mesoporous Support (SAMMS) sorbent, having at least one functional group adapted to selectively bind with a preselected ion. While in this embodiment a silica based porous substrate is described it is to be distinctly understood that the invention is not limited thereto but may be variously alternatively embodied to include a variety of combinations of rigid porous substrates with a specific functional group configured to interface with a particular portion of a target material. Examples of materials that could be utilized as the porous substrate include carbon based materials, titania, zirconia, and germania, as well as ceramic oxides such as aluminas and aluminosilicates. These backbone structures are connected to a specific interface in a variety of ways. In one embodiment an organosilane interface is utilized to connect the functional group interface to the backbone structure. This configuration allows for a column that does not swell and provides increased surface area and loading thus allowing for lower specific activity parent feeds to be utilized. In one application, the SAMMS sorbent is functionalized with a Copper-Ethylenediamine (CuEDA) complex, forming a binding site selectively configured to bind molybdate, allowing the sorbent to be so loaded. In another embodiment of the invention the sorbent includes a selective binding site formed by a metal thiolate-SAMMs material (e.g. silver thiolate SAMMS). While these two types of materials are described as particular embodiments of this invention, it is to be distinctly understood that a variety of materials and combinations could be utilized depending upon the particular needs and circumstances of the user. For example, a similar methodology can be utilized to produce rhenium-188 (Re-188) from its parent tungsten188 (W-188). In such a process, tungsten oxide (186WO3) is irradiated in a reactor to produce W-188. Using known techniques such as mixing with 0.1 M NaOH containing 5% sodium hypochlorite solution, the W-188 can be dissolved. Once dissolved, this sodium tungstate solution can then acidified to pH 2-5 and loaded on a CuEDA SAMMS column. The half life of W-188 is 69 days and produces the decay product Re-188 with a half life of 17 hours. The 188ReO4− oxoanion produced on the CuEDA SAMMS generator is preferentially released from the sorbent much as TcO4− oxoanion does. The breakthrough of tungstate and other undesired constituents in the eluent is reduced by the use of metal capped thiol-SAMMS, such as thiol-SAMMS capped with silver. The silver capped thiol-SAMMS will sequester tungstate as Ag2WO4. The Re-188 can then be eluted with saline or with the salt of a weak acid such as ammonium acetate. In addition to this example a variety of other types of materials could be produced according to such a configuration in accordance with the needs and necessities of the user, examples of such materials include the obtaining of Y-90 from Sr-90, Ra-224 from Th-228, Pb-212 from Ra-224, Bi-212 from Pb-212, Ra-225 from Th-229, Ac-225 from Ra-225, Bi-213 from Ac-225, Th-227 from Ac-227, and Ra-223 from Th-227. In these later embodiments the sorbent material has a functional group comprising a material such as actinide phosphate SAMMs material, a hydrogen phosphate SAMMS material, or a glycinyl urea SAMMs material. In some embodiments of the invention, additional sorbent contacting steps are included in the process either in the same structure as the first sorbent or in follow-on steps of a process. Such sorbents, for example, can help ensure sufficient radiochemical purity or concentration of the final radioisotope product for clinical use. In the embodiment of the invention for the generation of Tc-99m from Mo-99 a secondary sorbent phase (e.g. EDA SAMMS, thiol-SAMMs material, described in further detail hereafter) may be included to assist with the removal of copper from the eluent. In addition to utilization in the described embodiment, inclusion of a secondary capture material such as a thiol-SAMMS material as a follow on step or as an additional sorbent layer in a preexisting alumina type generator will provide increased purity. In addition to this secondary sorbent material a third type of material such as metal capped thiol SAMMS, such as silver (Ag) capped thiol SAMMs material may also be utilized to provide additional material specific capture. While this arrangement is shown and described it is to be distinctly understood that the invention is not limited to any specific embodiment or configuration and encompasses various alterations as dictated by the needs and necessities of the user. In one embodiment of the invention the process further includes the step of concentrating the target material, in this case Tc-99m, to a target value, in this case at least 25 millicurie Tc-99m/Mr. In one embodiment of the invention this is done by incorporating a secondary column that will load pertechnetate and provide subsequent small volume elution of Tc-99m. This additional column may also include acid-alumina and amine-based sorbents. In some embodiments the pertechnetate is rinsed from the ion exchange material using a rinsing solution, such as deionized water or saline. In some embodiments the pH of the various loading, generating and eluting phases (wherein the Mo-99 is loaded on to the sorbent, allowed to decay on the sorbent to form Tc-99m, and then eluted to remove the Tc-99m from the column) are performed in a step wise manner with varying pH from a lower pH, preferably a pH of about 3 at the loading stage to a higher pH, pH of about 4 at the generating stage and then an even higher pH, pH of about 5 at the elution stage. The present invention also includes a system for practicing the method described above. In one embodiment of the invention a Tc-99m generator is prepared by forming a packed particle sorbent column comprising Cu-EDA-SAMMS. Preferably this occurs in the particle range from about 50-300 microns and most preferably, at about 100 microns. While this configuration is shown it is to be distinctly understood that the sorbent is not limited solely to this structure and that a variety of other structures may also be utilized. Examples of these structures include but are not limited to packed beds, structured monoliths, coated structures, thin films, lined capillaries and other engineered forms. In other embodiments, another sorbent in addition to or in replacement of Cu-EDA-SAMMS may also be utilized. Examples of such other materials include a thiol-SAMMs, a capped metal thiol SAMMs material, or another sorbent having the desired properties. In applications where multiple sorbents are utilized to achieve a specific result these multiple sorbent sections need not necessarily be stacked, or even embodied in the same column as is shown in the detailed description provided hereinafter. In use, a solution of dissolved Mo-99-containing Mo is contacted with the Cu-EDA SAMMS material preferably at a pH of about 3. This Mo-99-containing Mo then absorbs or loads on to the SAMMs material where it is held for a designated period of time. This lower pH helps to enhance the amount of loading upon the material. In one set of experiments a pH of 3 was estimated to provide Tc99m recovery to more than 90 percent. In one embodiment the column contains less than 500 mL of unsupported Cu-EDA-SAMMS and is capable of sorbing at least 1600 to 4800 millicurie of Mo-99, depending on if natural molybdenum or Mo-98-enriched molybdenum is used as the neutron-capture target material for irradiation. Once the material has been loaded, the pH is then raised to about 4. While this step is shown in one embodiment of the invention it is to be distinctly understood that the invention is not limited thereto but maybe variously embodied according to the needs and necessities of the user. As the Mo-99 decays to form Tc-99m, the remaining Mo-99 will be preferentially bound to the sorbent. After a designated period of time, typically at or around 24 hours (at which time the maximum Tc99m activity occurs), the Tc-99m is then eluted at a pH of about 5 wherein the reaction chemistries show a preference for releasing the Tc-99m. This eluant can be buffered de-ionized water, DI or sterile saline which will make the captured Tc-99m ready for use. In some embodiments additional layers of absorbents within the same column, or different processing steps utilizing different absorbents passing the eluant though various other absorbent beds, other columns, or absorbent contact mechanisms may be desirable. The need or necessity to perform such actions may be precipitated by a variety of circumstances including but not limited to the specific activity of the Mo-99 containing material that is utilized, the substrate upon which the sorbent is placed, the interaction of these materials with the underlying acid, and other factors. As discussed previously in one embodiment of the invention, contacting the eluant from a standard alumina based Tc-99m generator to remove molybdate would result in a marked increase in the efficiency of these standard based systems and allow lower enriched or even naturally occurring Mo-99 to be utilized in these existing systems. The additional steps of contacting the eluant with various other sorbents could be done in a variety of ways. For example, in one example of one embodiment the absorbed Mo-99, when eluted with saline solution, provides a yield of 48% theoretical yield of Tc-99m over the life of the generator. When buffered to a neutral or near neutral pH labeling can then occur directly. In some embodiments the labeling is performed utilizing organic linkages so as to form labeled materials such as such as Tc99m[MIBI]6 where MIBI is 2-methoxyisobutyl isonitrile. While this example is given it is to be distinctly understood that the invention is not limited thereto but may be variously alternatively embodied according to the needs of the user. The purpose of the foregoing abstract is to enable the United States Patent and Trademark Office and the public generally, especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. Various advantages and novel features of the present invention are described herein and will become further readily apparent to those skilled in this art from the following detailed description. In the preceding and following descriptions are shown and described only the preferred embodiment of the invention, by way of illustration of the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of modification in various respects without departing from the invention. Accordingly, the drawings and description of the preferred embodiment set forth hereafter are to be regarded as illustrative in nature, and not as restrictive. The following description includes the preferred best mode of one embodiment of the present invention. It will be clear from this description of the invention that the invention is not limited to these illustrated embodiments but that the invention also includes a variety of modifications and embodiments thereto. Therefore, the present description should be seen as illustrative and not limiting. While the invention is susceptible of various modifications and alternative constructions, it should be understood that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims. In one embodiment of the invention, shown in FIG. 1(a), a Tc-99m generator (10) is prepared with neutron-capture produced molybdenum [98Mo(n,g)99Mo] absorbed on Cu-EDA-SAMMS ion-exchange material (12). In this embodiment lead shielding (20) also protects the column (22) from the exterior. In this embodiment a secondary sorbent material, a thiol-SAMMS (14), as well as a third sorbent material, a metal-capped thiol-SAMMS material (16) are also included. The system also includes a means for obtaining sterile solutions of sodium pertechnetate Tc 99m from the decay of 99Mo through an eluent rinsing process, wherein an eluent such as sterile saline or deionized water is flushed from one reservoir 26 through the column 22 to a second reservoir 24. To reduce radiation exposure to personnel, the column (22) is shielded by lead (20). In some other embodiments, such as the embodiment shown in FIG. 1(b) the eluent is fed from a first column 30 to a secondary column 40 where further removal of unwanted products can take place. The eluent can then be fed to a small volume elution column (60) where concentration and/or further removal of unwanted products can then take place. Part of the eluent stream can be separated and utilized for labeling or other use while other portions can be recycled, for example through a reservoir 50, and fed back through the columns 30, 40. In some applications, subsequent third or fourth columns may also be incorporated for concentration and/or further removal of unwanted products. While in this embodiment it is shown that various combinations of the sorbents 12, 14, 16 are located in various positions in the flow it is to be distinctly understood that the invention is not limited thereto but may be variously alternatively embodied whereby the position and location of these sorbents may be variously alternatively positioned and embodied. In one embodiment the column 22 contains less than 500 mL of unsupported Cu-EDA-SAMMS and is capable of sorbing at least 1600 to 4800 millicurie of 99Mo, depending on if natural molybdenum or 99Mo-enriched molybdenum is used as the neutron-capture target material for irradiation. The absorbed 99Mo, when eluted with saline solution, provides a yield of 48% theoretical yield of 99mTc over the life of the generator. While this embodiment is shown, it is to be distinctly understood that such an invention is capable of a variety of various alterations and alternative configurations. While in one embodiment of the invention irradiated molybdenum is shown, natural molybdenum has also been shown to possess sufficiently high Mo-99 activity to function as a part of the present invention. Preferably, the activity of the Mo-99 has an activity of at least 100 millicurie Mo99/gram of molybdenum. However the present invention also enables for Tc-99m to be produced using Mo-99 at specific activities up to that approaching 1/100th the activity of fission product Mo-99, or 5,000 curie/gram of molybdenum. While these examples are shown and described it is to be distinctly understood that the invention is not limited thereto but may be variously alternatively embodied according to the particular needs and necessities of a user. The high surface area ion-exchange material utilized in one embodiment of the present invention is a self assembled monolayer of the type described in U.S. Pat. No. 6,531,224, and U.S. Pat. No. 6,326,326 the contents of each are herein incorporated by reference. This type of material referred to as a SAMMs material provides a variety of functionalized portions self assembled upon a substrate. In one embodiment a Cu-EDA-SAMMs material is utilized. The Cu-EDA reference refers to the types of ligands and functional groups that are present upon the surface of the SAMMs material. Examples of the ligands for Cu-EDA SAMMS, thiol-SAMMs and metal capped thiol-SAMMS, are shown in FIG. 2a-2d. FIGS. 2a and 2b show two exemplary ligand structures for Cu-EDA-SAMMS. These materials have been shown to possess high loading capacity for molybdenum (sequestered as the anion molybdate) and are therefore good materials for capturing the activated molybdenum with Mo-99 activity. The high surface area of the silica mesoporous support (˜400 m2/g) enhances the loading capacity of the molybdenum anion (molybdate). Further, Cu-EDA-SAMMS possesses a higher affinity for molybdate than pertechnetate. The higher selectivity for molybdate over pertechnetate makes the Cu-EDA-SAMMS material a good candidate as a sorbent for the Tc-99m generator. FIG. 2(c) shows the general ligand structure for a thiol-SAMMS material while FIG. 2(d) shows the ligand structure of a metal in this case silver capped Thiol-SAMMs structure. In addition, amine based ligands, when attached to the mesoporous silica support structure display affinity for molybdate on the range of 76 mg/g of sorbent. FIGS. 2(e) and 2(f) show the structures of Acetamide Phosphate (AcPhos) SAMMs and Glycinyl-urea (Gly-Ur) SAMMs which are useful in other processes such as Th/Ra separations utilizing a structure and methodology similar to those taught in this application. As is shown in FIGS. 3-6, in one set of testing regarding the present invention, approximately 40 milligrams of either CuEDA SAMMS or carbon sorbent was placed in conical tubes. Ammonium molybdate stock solution was then added. The pH of the slurries of sorbent and ammonium molybdate were adjusted to 5 using 0.1 M HCl. The quantity of sorbent in the batch contact tests was 0.040 gram of CuEDA SAMMS (or carbon sorbent), and 5.9 mL of solution, for a phase ratio of 147.5. After confirming the correct pH (5) for the slurries, the conical tubes were quickly capped and transferred to a rotary shaker. The slurries were contacted in a batch contact test for 1 hour in a rotary shaker set at 200 RPM. Sorbent was not added to conical tube ID 13-07, as a control. Conical tubes 13-04 and 13-06 contained the carbon sorbent which was used a comparison. A diagram of the batch contact test sequence for the Mo-99 loading is shown on the top row of illustrations in FIG. 3. After the one hour of contact, the samples were centrifuged and filtered to retrieve a 2.0 mL aliquot for gamma counting. The results of the batch contact tests are shown in the table in FIG. 4. A total of seven batch contacts were performed, including the controls and tests with the carbon sorbent. All tests were performed at room temperature. Molybdenum loading for test 13-01 reports 17.65 microCi Mo99/g of SAMMS, (equal to 95 mg Mo/g of SAMMS) and is 20% greater than the reported molybdenum loading in previous cold (non-radioactive) tests. In cold tests the molybdenum loading was reported between 72-77 mg/g. In both tests the loading chemistry was pH 5. After loading, each of the six test samples were rinsed three times in DI water adjusted to acidic pH. In each of the rinsates, the DIW was adjusted to pH 4 with 0.1 M HCl. The samples were centrifuged and filtered between each of the three rinsing steps. Generator solutions comprised of DIW, pH adjusted to either 2.5 or 3 were admitted to each of the six rinsed sorbent samples. The volume of the DIW was 6.3 mL. Given the nominal mass of the sorbent as 40 mg, the phase ratio for the generation tests was approximately 157 ml/g. After adding the identified generator solution to the vials containing the sorbents, the pH of the slurry was confirmed to be at the specified value and the generation date and time was recorded. The samples were allowed to generate Tc-99m for a period of about 3 days. The samples were placed in rotary shaker set at 200 RPM for 1 hour. At the conclusion of the hour, the samples were centrifuged for 3 minutes and filtered. The centrifuge and filtration or separation time was recorded. A sample of filtered solution was measured with gamma spectrometry for the Mo-99 and Tc-99m content. The results of the gamma measurements are shown in FIGS. 4-7. FIG. 6 shows the Mo-99 activity of the loading, rinsing and generator solutions when contacted with the four candidate Cu-EDA sorbents. The plots of the four tests display a semi-log trend illustrating reduction of Mo-99 activity with each subsequent step. The reduction of Mo-99 activity in the contact solutions from the end of the rinsing step to the end of the generation step is attributed to both the increased sorption of molybdate from the solution and the decay of Mo-99. The half life of Mo-99 is 2.6 days, so the 3-day generation period alone will result in about one half reduction in the Mo-99 activity measurements. The Mo-99 activity in the generating solution is reduced by a factor of between 3 and 13. The Tc-99m trend for the CuEDA SAMMS materials displays a significantly different trend than those observed for the Mo-99 activity in the same test. Comparing the rinsate solutions to the generator solutions, the Tc-99m activity increased by a factor of 2-4 times. The yield of Tc99m from the decay of the Mo99 can be estimated by knowing: (1) the activity of Mo99 loaded on the sorbent, (2) the activity of the Tc99m in the generator solution, and (3) the separation time of the generator solution. The decay of Mo99 occurs in two-path decay chain, via the beta decay to Tc99m followed by isomeric transition to Tc99. The half life of parent Mo99 (66 hr), is ten times the half life of daughter Tc99m, (6.0 hr). In secular equilibrium, the fraction of Mo99 decaying to Tc99m is 87.5%. Various alterations to the basic example may be made so as to tailor the device and the process toward a specific end. For example, the studies revealed that the separation of Tc-99m from Mo-99 can be facilitated by sequentially lowering the pH of the load, rinse and generating solutions (from 5 to 4 to 3) respectively to achieve improved separation of Tc-99m from Mo-99. However, the data also indicates a lower (34%) utilization of the Tc-99m, suggesting the low pH of the generating solution enhanced the polymerization condensation of the sorbed molybdate and prevents Tc-99m from detachment. The results suggest using CuEDA SAMMS in acid conditions to generate Tc-99m may reduce its recovery due to polymerization condensation of the molybdate. Achieving improved removal of molybdenum from Cu-EDA SAMMs generator eluent may be made by selecting a sorbent or combination of materials exhibiting high selectivity of the removal of molybdate from pertechnetate solution. An example of such a material is silver thiolate-SAMMs, however a variety of other materials may also be utilized, these include but are not limited to; Cu-EDA SAMMS, Fe-EDA SAMMS, copper thiolate SAMMS, 8-hydroxyquiniline SAMMs or other materials that utilize a preselected ligand or functional group attached to a porous backbone structure. In another embodiment of the invention concentrating the Tc-99m in the generator solution to at least 25 millicurie/mL by incorporating a secondary column that will load pertechnetate and provide subsequent small volume elution of Tc-99m may also be utilized. Preferably, the secondary column will have a sufficient loading capacity for pertechnetate. The recommended class of sorbents for the volume reduction is amine-based sorbents, such as aminopropyl SAMMS, EDA SAMMS, diethylenetriamine (DETA) SAMMS, or other materials that utilize a preselected ligand or functional group attached to a porous backbone structure. In addition to altering the various sorbents that are utilized, improved recovery of pertechnetate from the Cu-EDA-SAMMs sorbent can be obtained by selecting loading, rinsing and generating solutions to reduce polymerization condensation of molybdate. It is recommended that the pH of the loading, rinsing or generating solution be raised to reduce the polymerization of molybdate and its likely interference to the release (or detachment) of pertechnetate from CuEDA SAMMS. The present invention can also be used to produce labeling compounds such as those used in Sestamibi, DTPA and MAA scans. In some applications it will be possible to obtain a final Tc-99m separation well above the target baseline of 6,700 (Tc-99m/Mo-99), and sufficient elution performance to achieve at least 25 millicurie/mL when starting with a fully irradiated target. While various preferred embodiments of the invention are shown and described, it is to be distinctly understood that this invention is not limited thereto but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims.
060118261	claims	1. A steam power station, comprising: a wall; a steam conduit leading through said wall and forming a fixed point with said wall for introduction of forces and moments; a main valve having a housing and a given nominal width, said main valve connected to said steam conduit at said fixed point, without a high-pressure pipe interposed; satellite valves having housings and nominal widths smaller than said given nominal width, said satellite valves fastened to said housing of said main valve, without a high-pressure pipe interposed; and at least one additional valve having a housing fastened to said housing of at least one of said satellite valves, without a high-pressure pipe interposed and without any support. a wall; a steam conduit leading through said wall and forming a fixed point with said wall for introduction of forces and moments; a main valve having a housing and a given nominal width, said main valve connected to said steam conduit at said fixed point, without a high-pressure pipe interposed; satellite valves having housings and nominal widths smaller than said given nominal width, said satellite valves fastened to said housing of said main valve, without a high-pressure pipe interposed; and at least one additional valve having a housing fastened to said housing of at least one of said satellite valves, without a high-pressure pipe interposed and without any support. 2. The steam power station according to claim 1, wherein said at least one additional valve is a plurality of additional valves having mutually aligned housings forming a row, said additional valves including a first additional valve, and said housing of said first additional valve fastened to said housing of one of said satellite valves, without a high-pressure pipe interposed. 3. The steam power station according to claim 1, including at least one supplementary valve having a housing fastened to said housing of said at least one additional valve, without a high-pressure pipe interposed and without any support. 4. The steam power station according to claim 3, wherein said at least one supplementary valve is a plurality of supplementary valves having mutually aligned housings forming a row, said supplementary valves including a first supplementary valve, and said housing of said first supplementary valve fastened to said housing of said at least one additional valve, without a high-pressure pipe interposed. 5. A nuclear power station, comprising:
	abstract	A method and apparatus for producing heat is disclosed. The method involves the steps of accelerating one or more first particle(s) to a first velocity; colliding the accelerated particle(s) with one or more second particles in a collision zone located within a housing causing the first particle(s) and second particle(s) to form one or more collision mass(es) containing subatomic particles of the first and second particles; controlling the position of the collision mass(es) with electric and/or magnetic fields; and introducing one or more further particle(s) into the collision mass(es), the further particle(s) undergoing nuclear fusion with the one or more particles in the collision mass(es) producing fusion products and releasing heat.
	abstract	A system and method for detecting and analyzing anomalies in a machine during operation. The system and method includes at least one sensor associated with a component on the machine, a transducer configured to be positioned about the component, and a test station for receiving signals from the at least one sensor and the transducer, and correlating the signals to determine a source of an anomaly.
053435087	abstract	A retainer is for retaining a grid on a fuel assembly. The retainer has at least one aperture at one end thereof for receiving a shoulder on a guide control tube and legs on the other end thereof for welding to the grid. The one end of the retainer is captured between the shoulder and a surface on the bottom nozzle of the fuel assembly when the guide tube is attached to the bottom nozzle. The retainer reduces the rotation of the guide tube resulting from torquing of the screws which connect the guide tube to the bottom nozzle thereby increasing the integrity of the assembly.
055369456	abstract	A method and apparatus for transporting syringes containing radioactive material. The apparatus includes a radiopharmaceutical pig having an inner chamber in which a sharps container can be secured. The sharps container has a housing and an attachable cap. The method includes assembling the radiopharmaceutical pig so that the chamber of the radiopharmaceutical pig contains the syringe in the sharps container housing. The radiopharmaceutical pig is disassembled, where upon the syringe is removed, discharged, and then replaced in the sharps container housing. The cap of the sharps container is affixed to the housing of the sharps container, thus enclosing the contaminated syringe therein. The radiopharmaceutical pig is assembled so that its chamber contains the sharps container and the syringe. The radiopharmaceutical pig is transported to a disposal area, where it is disassembled and the sharps container containing the syringe is placed in a particular disposal container.
	claims	1. A method, comprising: exposing a layer of photoresist in accordance with a first writing pattern in a first area of said layer of photoresist; and exposing said layer of photoresist in accordance with a second writing pattern in a second area of said layer of photoresist, said first and second areas overlapping one another in at least one region, wherein said first and second writing patterns are created by separating digital data corresponding to a desired pattern for a reticle into at least two separate groups of data, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern. 2. The method of claim 1 , further comprising removing portions of the layer of photoresist. claim 1 3. The method of claim 1 , further comprising removing exposed portions of said layer of photoresist in said first and second areas. claim 1 4. The method of claim 2 , further comprising performing an etching process to define a pattern in an opaque layer positioned under said layer of photoresist. claim 2 5. The method of claim 4 , wherein said opaque layer is comprised of a metal or a metal alloy. claim 4 6. The method of claim 4 , wherein said opaque layer is comprised of chromium. claim 4 7. The method of claim 1 , wherein said layer of photoresist is comprised of at least one of a positive photoresist material and a negative photoresist material. claim 1 8. The method of claim 1 , further comprising exposing said layer of photoresist in accordance with a third writing pattern in a third area of said layer of photoresist. claim 1 9. The method of claim 8 , wherein said third area of said layer of photoresist overlaps at least one of said first and second areas in at least one area. claim 8 10. The method of claim 4 , further comprising exposing a portion of a layer of photoresist formed above a process layer by directing radiant energy through said reticle. claim 4 11. The method of claim 1 , wherein said layer of photoresist is formed above an opaque layer of a reticle. claim 1 12. The method of claim 1 , wherein said layer of photoresist is formed above at least one of a semiconducting substrate and a process layer. claim 1 13. A method of forming a reticle, comprising: forming a layer of photoresist above an opaque layer; exposing said layer of photoresist in accordance with a first writing pattern in a first area of said layer of photoresist; and exposing said layer of photoresist in accordance with a second writing pattern in a second area of said layer of photoresist, said first and second areas overlapping one another in at least one region, wherein said first and second writing patterns are created by separating digital data corresponding to a desired pattern for said reticle into at least two separate groups of data, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern. 14. The method of claim 13 , further comprising removing portions of the layer of photoresist. claim 13 15. The method of claim 13 , further comprising removing exposed portions of said layer of photoresist in said first and second areas. claim 13 16. The method of claim 14 , further comprising performing an etching process to define a pattern in said opaque layer. claim 14 17. The method of claim 13 , wherein said opaque layer is comprised of a metal or a metal alloy. claim 13 18. The method of claim 13 , wherein said opaque layer is comprised of chromium. claim 13 19. The method of claim 13 , wherein said layer of photoresist is comprised of at least one of a positive photoresist material and a negative photoresist material. claim 13 20. The method of claim 13 , further comprising exposing said layer of photoresist in accordance with a third writing pattern in a third area of said layer of photoresist. claim 13 21. The method of claim 20 , wherein said third area of said layer of photoresist overlaps at least one of said first and second areas in at least one area. claim 20 22. The method of claim 16 , further comprising exposing a portion of a layer of photoresist formed above a process layer by directing radiant energy through said reticle. claim 16 23. A method of forming a reticle, comprising: forming a layer of photoresist above an opaque layer; exposing said layer of photoresist in accordance with a first writing pattern in a first area of said layer of photoresist; exposing said layer of photoresist in accordance with a second writing pattern in a second area of said layer of photoresist, said first and second areas of said layer of photoresist overlapping one another in at least one area, wherein said first and second writing Patterns are created by separating digital data corresponding to a desired pattern for said reticle into at least two separate groups of data, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern; and removing exposed portions of the layer of photoresist in said first and second areas. 24. The method of claim 23 , further comprising performing an etching process to define a pattern in said opaque layer. claim 23 25. The method of claim 23 , wherein said opaque layer is comprised of a metal or a metal alloy. claim 23 26. The method of claim 23 , wherein said opaque layer is comprised of chromium. claim 23 27. The method of claim 23 , wherein said layer of photoresist is comprised of a positive photoresist material. claim 23 28. The method of claim 23 , further comprising exposing said layer of photoresist in accordance with a third writing pattern in a third area of said layer of photoresist. claim 23 29. The method of claim 28 , wherein said third area of said layer of photoresist overlaps at least one of said first and second areas in at least one region. claim 28 30. The method of claim 24 , further comprising exposing a portion of a layer of photoresist formed above a process layer by directing radiant energy through said reticle. claim 24 31. A method of forming a reticle, comprising: creating a collection of digital data corresponding to a desired pattern for said reticle; and separating said collection of digital data into at least two separate groups of data, a first of said data groups being used to define a first writing pattern for said reticle, a second of said data groups being used to define a second writing pattern for said reticle, wherein said first and second writing patterns overlap one another in at least one region. 32. The method of claim 31 , further comprising performing said first and second writing patterns on a layer of photoresist positioned above an opaque layer. claim 31 33. The method of claim 32 , further comprising removing portions of the layer of photoresist. claim 32 34. The method of claim 33 , further comprising performing an etching process to define a pattern in an opaque layer positioned under said layer of photoresist. claim 33 35. The method of claim 34 , wherein said opaque layer is comprised of a metal or a metal alloy. claim 34 36. The method of claim 34 , wherein said opaque layer is comprised of chromium. claim 34 37. The method of claim 32 , wherein said layer of photoresist is comprised of at least one of a positive photoresist material and a negative photoresist material. claim 32 38. The method of claim 31 , wherein said collection of digital data is separated into at least three separate groups of data, a third of said data groups being used to define a third writing pattern for said reticle, wherein said third reticle writing pattern overlaps at least one of said first and second writing patterns in at least one region. claim 31 39. The method of claim 34 , further comprising exposing a portion of a layer of photoresist formed above a process layer by directing radiant energy through said reticle. claim 34 40. A method, comprising: providing a semiconducting substrate having a process layer formed thereabove and a first layer of photoresist formed above said process layer; and exposing at least a portion of said first layer of photoresist by directing radiant energy through a reticle, said reticle being formed by: exposing a second layer of photoresist formed above an opaque layer in accordance with a first writing pattern in a first area of said second layer of photoresist; exposing said second layer of photoresist in accordance with a second writing pattern in a second area of said second layer of photoresist, said first and second areas of said second layer of photoresist overlapping one another in at least one region, wherein said first and second writing patterns are created by separating digital data corresponding to a desired pattern for said reticle into at least two separate groups of data, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern; and removing portions of the second layer of photoresist in said first and second areas; and performing an etching process to define a pattern in said opaque layer. 41. The method of claim 40 , wherein said opaque layer is comprised of a metal or a metal alloy. claim 40 42. The method of claim 40 , wherein said opaque layer is comprised of chromium. claim 40 43. The method of claim 40 , wherein said first layer of photoresist is comprised of a positive photoresist material. claim 40 44. The method of claim 40 , wherein said second layer of photoresist is comprised of a positive photoresist material. claim 40 45. A method, comprising: forming a layer of photoresist above at least one of a semiconducting substrate and a process layer; exposing said layer of photoresist in accordance with a first writing pattern in a first area of said layer of photoresist; and exposing said layer of photoresist in accordance with a second writing pattern in a second area of said layer of photoresist, said first and second areas overlapping one another in at least one region, wherein said first and second writing patterns are created by separating digital data corresponding to a desired pattern for said layer of photoresist into at least two separate groups of data, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern. 46. The method of claim 45 , wherein said process layer is comprised of at least one of an insulating material, a layer of metal and a layer of polysilicon. claim 45 47. The method of claim 45 , further comprising removing portions of the layer of photoresist. claim 45 48. The method of claim 45 , further comprising removing exposed portions of said layer of photoresist in said first and second areas. claim 45 49. The method of claim 46 , further comprising performing an etching process to define a pattern in at least one of said substrate and said process layer. claim 46 50. The method of claim 45 , wherein said layer of photoresist is comprised of at least one of a positive photoresist material and a negative photoresist material. claim 45 51. The method of claim 45 , further comprising exposing said layer of photoresist in accordance with a third writing pattern in a third area of said layer of photoresist. claim 45 52. The method of claim 51 , wherein said third area of said layer of photoresist overlaps at least one of said first and second areas in at least one area. claim 51 53. A method, comprising: forming a layer of photoresist above at least one of a semiconducting substrate and a process layer; exposing said layer of photoresist in accordance with a first writing pattern in a first area of said layer of photoresist; exposing said layer of photoresist in accordance with a second writing pattern in a second area of said layer of photoresist, said first and second areas of said layer of photoresist overlapping one another in at least one area, wherein said first and second writing patterns are created by separating digital data corresponding to a desired pattern for said layer of photoresist into at least two separate groups of data, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern; and removing exposed portions of the layer of photoresist in said first and second areas. 54. The method of claim 53 , further comprising performing an etching process to define a pattern in at least one of said substrate and said process layer. claim 53 55. The method of claim 53 , wherein said process layer is comprised of at least one of an insulating material, a layer of metal and a layer of polysilicon. claim 53 56. The method of claim 53 , wherein said layer of photoresist is comprised of a positive photoresist material. claim 53 57. The method of claim 53 , further comprising exposing said layer of photoresist in accordance with a third writing pattern in a third area of said layer of photoresist. claim 53 58. The method of claim 57 , wherein said third area of said layer of photoresist overlaps at least one of said first and second areas in at least one region. claim 57 59. A method, comprising: forming a layer of photoresist above at least one of a semiconducting substrate and a process layer; creating a collection of digital data corresponding to a desired pattern for said layer of photoresist; and separating said collection of digital data into at least two separate groups of data, a first of said data groups being used to define a first writing pattern for said layer of photoresist, a second of said data groups being used to define a second writing pattern for said layer of photoresist, wherein said first and second writing patterns overlap one another in at least one region. 60. The method of claim 59 , further comprising performing said first and second writing patterns on at least one of said substrate and said process layer. claim 59 61. The method of claim 60 , further comprising removing portions of the layer of photoresist. claim 60 62. The method of claim 61 , further comprising performing an etching process to define a pattern in at least one of said substrate and said process layer. claim 61 63. The method of claim 59 , wherein said process layer is comprised of at least one of an insulating material, a layer of metal and a layer of polysilicon. claim 59 64. The method of claim 60 , wherein said layer of photoresist is comprised of at least one of a positive photoresist material and a negative photoresist material. claim 60 65. The method of claim 59 , wherein said collection of digital data is separated into at least three separate groups of data, a third of said data groups being used to define a third writing pattern for said layer of photoresist, wherein said third reticle writing pattern overlaps at least one of said first and second writing patterns in at least one region. claim 59 66. An exposure system, comprising: an electron beam source; and a controller that is adapted to direct electrons emitted by said electron beam source so as to: expose a layer of photoresist in accordance with a first writing pattern in a first area of a layer of photoresist, and expose said layer of photoresist in accordance with a second writing pattern in a second area of said layer of photoresist, said first and second areas of said layer of photoresist overlapping one another in at least one region, wherein said controller is adapted to perform said first and second writing patterns by processing separate groups of digital data corresponding to a desired pattern, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern. 67. The system of claim 66 , wherein said layer of photoresist is formed above at least one of a semiconducting substrate and a process layer. claim 66 68. The system of claim 66 , wherein said layer of photoresist is formed above an opaque layer of a reticle. claim 66 69. The system of claim 68 , wherein said opaque layer is comprised of a metal or a metal alloy. claim 68 70. The system of claim 68 , wherein said opaque layer is comprised of chromium. claim 68 71. The system of claim 66 , wherein said layer of photoresist is comprised of at least one of a positive photoresist material and a negative photoresist material. claim 66 72. The system of claim 66 , wherein said controller is further adapted to expose said layer of photoresist in accordance with a third writing pattern in a third area of said layer of photoresist. claim 66 73. The system of claim 72 , wherein said third area of said layer of photoresist overlaps at least one of said first and second areas in at least one region. claim 72 74. A reticle writing system, comprising: an electron beam source; and a controller that is adapted to direct electrons emitted by said electron beam source so as to: expose a layer of photoresist in accordance with a first writing pattern in a first area of a layer of photoresist formed above an opaque layer of a reticle, and expose said layer of photoresist in accordance with a second writing pattern in a second area of said layer of photoresist, said first and second areas of said layer of photoresist overlapping one another in at least one region, wherein said controller is adapted to perform said first and second writing patterns by processing separate groups of digital data corresponding to a desired pattern for said reticle, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern. 75. The system of claim 74 , wherein said exposure of said layer of photoresist is performed at an energy level of approximately 50 keV. claim 74 76. The system of claim 74 , wherein said opaque layer is comprised of a metal or a metal alloy. claim 74 77. The system of claim 74 , wherein said opaque layer is comprised of chromium. claim 74 78. The system of claim 74 , wherein said layer of photoresist is comprised of at least one of a positive photoresist material and a negative photoresist material. claim 74 79. The system of claim 74 , wherein said controller is further adapted to expose said layer of photoresist in accordance with a third writing pattern in a third area of said layer of photoresist. claim 74 80. The system of claim 79 , wherein said third area of said layer of photoresist overlaps at least one of said first and second areas in at least one region. claim 79 81. An exposure system, comprising: an electron beam source; and a controller that is adapted to direct electrons emitted by said electron beam source so as to: expose a layer of photoresist in accordance with a first writing pattern in a first area of a layer of photoresist formed above at least one of a semiconducting substrate and a process layer, and expose said layer of photoresist in accordance with a second writing pattern in a second area of said layer of photoresist, said first and second areas of said layer of photoresist overlapping one another in at least one region, wherein said controller is adapted to perform said first and second writing patterns by processing separate groups of digital data corresponding to a desired pattern, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern. 82. The system of claim 81 , wherein said process layer is comprised of at least one of an insulating material, a layer of metal and a layer of polysilicon. claim 81 83. The system of claim 81 , wherein said layer of photoresist is comprised of at least one of a positive photoresist material and a negative photoresist material. claim 81 84. The system of claim 81 , wherein said controller is further adapted to expose said layer of photoresist in accordance with a third writing pattern in a third area of said layer of photoresist. claim 81 85. The system of claim 84 , wherein said third area of said layer of photoresist overlaps at least one of said first and second areas in at least one region. claim 84 86. A wafer exposure system, comprising: a light source; a stage for receiving a semiconducting substrate having a process layer formed there-above and a first layer of photoresist formed above said process layer; a reticle, said reticle being formed by: exposing a second layer of photoresist formed above an opaque layer in accordance with a first writing pattern in a first area of said second layer of photoresist, and exposing said second layer of photoresist in accordance with a second writing pattern in a second area of said second layer of photoresist, said first and second areas of said second layer of photoresist overlapping one another in at least one region, wherein said first and second writing patterns are created by separating digital data corresponding to a desired pattern for said reticle into at least two separate groups of data, a first of said data groups being used to define said first writing pattern and a second of said data groups being used to define said second writing pattern; and a controller adapted to expose at least a portion of said first layer of photoresist by directing light from said light source through said reticle. 87. The system of claim 86 , wherein said opaque layer is comprised of a metal or a metal alloy. claim 86 88. The system of claim 86 , wherein said opaque layer is comprised of chromium. claim 86 89. The system of claim 86 , wherein said first layer of photoresist is comprised of a positive photoresist material. claim 86 90. The system of claim 86 , wherein said second layer of photoresist is comprised of a positive photoresist material. claim 86
040240185	description	DESCRIPTION OF THE PREFERRED EMBODIMENTS In the construction of liquid metal cooled fast breeder reactor of the pool kind shown in FIG. 1 there is shown a primary vessel 1 suspended from the cover of a concrete vault 2 and containing a pool 3 of liquid sodium. The reactor core 4 is suspended on a diagrid 5 from the cover of the concrete vault. The sodium coolant pumps and heat exchangers of the construction are not shown in the drawing but they also are suspended from the cover of the concrete vault 2 and immersed in the pool 3 of liquid sodium. A core tank 6 surrounds the reactor core and alongside the core tank there is a fuel transfer rotor 7 rotatably supported from the cover of the vault 2. A transfer port 9 in the core tank provides passage for irradiated fuel assemblies from the core to the transfer rotor 7 and there is a discharge port 10 in the cover of the concrete vault 2 for the withdrawal of fuel assemblies. The rotor carries equally circumferentially spaced stainless steel containers 11 and a charge machine (not shown) disposed above the cover of the concrete vault 2 is used to lift spent fuel assemblies from the core 4 and transfer them to individual buckets 12 in the containers 11. The transfer rotor is rotated by a shaft 13 from above the cover of the concrete vault in step-wise manner to present successive buckets to the transfer port 9 and to present them in step-wise manner to the discharge port 10. Energy absorbers 14 are shown diagrammatically and are provided in a base 8 directly beneath the transfer port 9 and the discharge port 10 for fuel assemblies. A transfer rotor 7 is shown in greater detail in FIG. 2 and comprises a horizontally disposed receiver 15 mounted on a vertical composite shaft 16. The receiver and shaft assembly is steadied by a tubular pedestal 17 mounted on a base 18. The shaft extends through an opening 19 in the cover of the concrete vault 3 where it is end supported in a bearing 20; the lower end is guided by a bush 21 and complementary stub shaft 22 which is located on the pedestal in a spherical mounting 23. Step wise rotation of the rotor 7 is effected by drive means (not shown) through a gear wheel 39 at the upper end of the shaft 16. The receiver 15 comprises a central boss 24 secured to the composite shaft 16 and having twenty arms 25 extending radially outwards from it. The arms 25 engage the boss 24 by hook connections 26 and are retained in engagement by two clamping plates 27, 28. The free ends of the arms 25 each have an aperture 29 housing a vertical open top container 11. The container of each arm 25 has a circumferential flange 30 and is supported on a helical coil compression spring 31 housed within a sleeve 32 depending from the lower face of the arm. A second helical coil compression spring 33 about the container 11 and housed within the aperture 29 abuts, at one end, the upper face of the flange 30 and, at the other end, an abuttment flange 34 of the arm. The base 18 carries two dash pot cylinders 35 having bores 36 which converge towards the lower closed end of the cylinders, there being one cylinder disposed in positions immediately below each of the transfer port 9 and discharge port 10. The lower end of each container 11 forms a piston 37 complementary to the dash pot cylinders 35. The containers each house a bucket 12 for receiving fuel assemblies from the reactor core and which have a lip 38 for engagement by lifting means which can withdraw the bucket complete with fuel assembly and sodium through the cover of the concrete vault 2. In the event of a malfunction whereby a fuel assembly is released in passage through the transfer port 9 or a bucket-fuel assembly-sodium combination is released on passage through the discharge port 10, the load falls into a container 11 disposed above an energy absorbing device. The container is driven downwardly compressing the spring 31 and energy is dissipated in the form of heat by displacement of sodium from the cylinder 35 through the diminishing limited clearance between the piston 37 and the wall of the cylinder 35. When the container and load have been brought to rest by the dash pot, the helical coil spring 31 returns the container and load to the normal operating position in the rotor, recoil vibrations being damped by the two opposed springs 31, 33. The construction has the advantage that sacrificial components such as deformable shock absorbers are eliminated. In an alternative construction the cylinders and pistons of the dash pots form unitary combinations which are located in the base. Each dash pot unit presents a plane striker platform to the lower end of the descending container. A dash pot unit is shown in FIG. 3 and comprises a cylinder 40, having a closed end, and a piston 41 which are normally urged to a vertically extended condition by a helical coil compression spring 42. The piston comprises an inverted cup having a circular flange 43 and the extent of travel of the piston in the cylinder is limited by a pad 44 in the base of the cylinder and four equally spaced lugs 45 extending radially inwards from a flange 46. The piston has a flange at the upper end which presents a striker platform 47 to containers 11 and is guided during downward travel by a coaxial tubular extension 48 of the cylinder. The striker platform 47 is generally circular but has four sectors cut away to present four equally spaced arcuate bearing surfaces 49 for guiding the piston within the extension. The bore of the cylinder converges towards the closed lower end so that a peripheral clearance between the piston or cylinder diminishes as the piston travels downwardly towards the lower end. The extension has apertures 50 in the wall for the discharge of sodium and a lip 51 for engagement by a lifting grab. When the piston is driven downwardly by a container, liquid sodium is ejected from the cylinder by way of the clearance between the piston and cylinder, thence through the apertures 50 and the segmented passages bounded by the striker platform 47 and the extension 48. When a dash pot as shown in FIG. 3 is used instead of that shown in FIG. 2, misalignment tolerances of the rotor relative to the dash pot can be greatly relaxed.
	claims	1. A plasma generator for use in a low energy beam line within an ion implantation system, comprising:a plasma energizing component configured to generate electric fields around the energizing component for a predetermined time during a discharge phase;a controller configured to activate the plasma energizing component for the predetermined time in the discharge phase and inhibit the energizing component in an after glow phase, wherein the predetermined time is a function of a measured plasma density value provided thereto, or a measured beam current value provided thereto. 2. The plasma generator of claim 1, further comprising cusp field elements for generating a cusp field therein and configured to lengthen the after glow phase of the energizing component. 3. The plasma generator of claim 1, wherein the energizing component is configured to generate pulsed energizing fields for a predetermined time to generate a plasma and enhance beam current of an ion beam passing therethrough. 4. The plasma generator of claim 1, wherein the after glow phase comprises a predetermined time that is a function of a plasma density. 5. The plasma generator of claim 1, wherein the activated energizing component promotes neutralization of ions of an ion beam by pulsing electric fields to generate a plasma, and wherein deactivation of the energizing component dampens electric fields imposed in the discharge phase and the generated plasma neutralizes the ion beam in the after glow phase. 6. An ion implantation system, comprising:an ion beam source configured to generate an ion beam;a mass analyzer for mass analyzing the ion beam generated;a pulsed plasma generator located downstream of the ion beam generator and configured to generate a pulsed plasma discharge to the ion beam passing therethrough, wherein the pulsed plasma generator is configured to generate pulses of the energizing field based on a duty cycle that is a function of beam current of the ion implantation system;an end station configured to support a workpiece that is to be implanted with ion by the ion beam. 7. The ion implantation system of claim 6, wherein the pulsed plasma generator is configured to generate pulses of the pulsed plasma discharge periodically with a duty cycle. 8. The ion implantation system of claim 6, wherein the pulsed plasma generator comprises:a gas source for providing gas particles, andan energizing component configured to generate pulses of an energizing field to excite the gas particles into the pulsed plasma discharge. 9. The ion implantation system of claim 8, wherein the energizing field is a static electric field or an electromagnetic field in one of a radiofrequency range and a microwave range. 10. The ion implantation system of claim 6, wherein the pulsed plasma generator comprises at least one magnetic cusp field element configured to generate magnetic cusp fields within the pulsed plasma generator to prolong an after glow phase. 11. The ion implantation system of claim 7, wherein the energizing field component comprises:an electrode,wherein the electrode generates the energizing field that ionizes the gas particles and produces the pulsed plasma discharge,wherein the pulsed plasma discharge comprises a neutralizing plasma that decreases space-charge effects acting on an ion beam below a low ion beam energy threshold. 12. The ion implantation system of claim 6, wherein the pulsed plasma generator is configured to neutralize the ion beam by reducing beam generated electric fields during a discharge phase, and to generate energizing fields during a predetermined time by generating the pulsed plasma discharge. 13. An ion implantation system, comprising:an ion beam source configured to generate an ion beam;a mass analyzer for mass analyzing the ion beam generated;a pulsed plasma generator located downstream of the ion beam generator and configured to generate a pulsed plasma discharge to the ion beam passing therethrough;an end station configured to support a workpiece that is to be implanted with ion by the ion beam,wherein the pulsed plasma generator is configured to prevent generation of energizing fields during a predetermined time in an after glow phase until a plasma density reaches a predetermined critical low value. 14. An ion implantation system, comprising:an ion beam source configured to generate an ion beam;a mass analyzer for mass analyzing the ion beam generated;a pulsed plasma generator located downstream of the ion beam generator and configured to generate a pulsed plasma discharge to the ion beam passing therethrough;an end station configured to support a workpiece that is to be implanted with ion by the ion beam;a measurement component configured to measure at least one ion implantation characteristic; anda controller operatively coupled to the measurement component and the pulsed plasma generator, wherein the controller adjusts the pulsed plasma generator in response to at least one ion implantation characteristic measurement including beam current. 15. A method of implanting ions into a workpiece in an ion implantation system, comprising:generating an ion beam in the ion implantation system;activating a plasma discharge generator to create a plasma discharge in a volume through which the ion beam passes for a predetermined time in a discharge phase, wherein the predetermined time is a function of a measured plasma density or a measured beam current. 16. The method of claim 15, wherein pulsing the plasma discharge to the ion beam comprises:introducing a gas in a path of the ion beam, andproducing an energizing field that ionizes the gas creating a discharge to neutralize the ion beam. 17. The method of claim 16, wherein the energizing field is an electromagnetic field, and wherein producing the energizing field comprises activating the plasma discharge generator according to a duty cycle that is a function of a beam current of the ion beam generated. 18. The method of claim 15, further comprises generating magnetic cusp fields within the pulsed plasma generator to prolong the after glow phase, and wherein the predetermined time is a function of the plasma density of the discharge. 19. The method of claim 15, further comprising:measuring at least one ion implantation characteristic; andadjusting a timing of the activation of plasma discharge generator in response to at least one ion implantation characteristic measurement.
	claims	1. A method for manufacturing a cylindrical member comprising:end bending a first end portion and a second end portion of a plate material to form a first end bending portion in which a length in a first direction is equal to or longer than a preliminary length in the first end portion and a second end bending portion in which a length in the first direction is equal to or longer than the preliminary length in the second end portion wherein the plate material extends in the first direction and includes the first end portion and the second end portion which are opposed to each other in the first direction;primary grooving each of the first end bending portion and the second end bending portion to remove each of the first end bending portion and the second end bending portion by a predetermined length of the preliminary length in the first direction while leaving extra length;bending the plate material over an entire length along the first direction, in such a manner that the plate material has a ring shape;secondary grooving each of the first end bending portion and the second end bending portion of the plate material having the ring shape; andjoining the first end bending portion and the second end bending portion to manufacture the cylindrical member. 2. The method for manufacturing a cylindrical member according to claim 1, wherein a first end surface of the first end bending portion and a second end surface of the second end bending portion which are opposed each other are processed to be parallel in the secondary grooving. 3. The method for manufacturing a cylindrical member according to claim 2, wherein the first end surface and the second end surface are processed to be parallel on the basis of an inner circumference length and an outer circumference length of the plate material having the ring shape, in the secondary grooving. 4. The method for manufacturing a cylindrical member according to claim 1, wherein the joining is performed in such a manner that the first end bending portion and the second end bending portion are joined by electron beam welding.
	description	Priority is claimed to Japanese Patent Application No. 2010-057639, filed Mar. 15, 2010, the entire content of which is incorporated herein by reference. 1. Technical Field The present invention relates to a line scanning apparatus which performs scanning control of a line scanning beam. 2. Description of the Related Art As a related art in such a field, a charged particle beam irradiation apparatus includes a scanning electromagnet for performing scanning of a charged particle beam, control device which controls the operation of the scanning electromagnet, and a monitor which detects the position of a beam, and performs continuous irradiation while performing scanning of the charged particle beam along an irradiation line of an irradiation field set in an object to be irradiated. According to an embodiment of the invention, there is provided a line scanning apparatus including a beam irradiation unit which radiates a line scanning beam, an irradiation position detection unit which detects an irradiation position of the line scanning beam, a stationary time measuring unit which measures the stationary time of the line scanning beam at the irradiation position detected by the irradiation position detection unit, and a scanning control unit which performs scanning control of the line scanning beam by utilizing the irradiation position detected by the irradiation position detection unit and the stationary time measured by the stationary time measuring unit. In the irradiation apparatus as described above, it is necessary to avoid a situation where parts other than an irradiation field are irradiated with a charged particle beam or a situation where the same part is excessively irradiated. For this reason, an irradiation apparatus with high reliability which can perform high-precision control of a charged particle beam is required. Thus, it is desirable to provide a line scanning apparatus which can improve reliability. According to the line scanning apparatus related to the embodiment of the invention the irradiation position of the line scanning beam is detected and the stationary time corresponding to the irradiation position is measured, and scanning control of the line scanning beam is performed by utilizing these results, so that irradiation of the line scanning beam to an erroneous position or excessive irradiation of the line scanning beam can be more reliably prevented, and thereby the reliability of the line scanning apparatus can be improved. The line scanning apparatus related to the embodiment of the invention may further include an interlock control unit which performs interlock control by utilizing the irradiation position detected by the irradiation position detection unit and the stationary time measured by the stationary time measuring unit. In this case, if the line scanning beam is radiated to an erroneous position or is excessively radiated so as to exceed a predetermined time, the erroneous irradiation of the line scanning beam can be prevented by performing the interlock control of stopping the irradiation of the line scanning beam. Additionally, in the line scanning apparatus related to the embodiment of the invention, the scanning control unit may perform feedback control of scanning of the line scanning beam by utilizing the irradiation position detected by the irradiation position detection unit and the stationary time measured by the stationary time measuring unit. In this case, high-precision scanning control of a line scanning beam is realized by the feedback control, and thereby the reliability of a line scanning apparatus can be improved. Hereinafter, a line scanning apparatus related to a preferred embodiment of the invention will be described in detail with reference to the drawings. As shown in FIG. 1, the line scanning apparatus 1 related to the present embodiment is utilized in a particle beam therapy facility which performs scanning of line scanning beams, such as a proton beam and a carbon ion beam, thereby irradiating a affected part of a patient to perform cancer treatment or the like, and controls the scanning of the line scanning beams. The line scanning apparatus 1 includes an irradiation nozzle (beam irradiation means) 2 which irradiates an irradiation field set in an affected part of a patient with a line scanning beam. In the particle beam therapy using such a line scanning beam, in order to reduce a risk due to erroneous irradiation of the line scanning beam, medical treatment proceeds by irradiating the inside of the irradiation field a plurality of times with a beam with suppressed intensity. The irradiation nozzle 2 is connected to an accelerator 4 through a beam transport system 3. The accelerator 4 is a cyclotron, a synchrotron, or the like which accelerates charged particles, such as a proton and a carbon ion. Charged particles accelerated by the accelerator 4 are shaped into a pencil beam with a diameter of several millimeters, and enter the beam transport system 3. A beam L of the charged particles, which is supplied to a supply port 2a of the irradiation nozzle 2 through the beam transport system 3, is emitted from an irradiation port 2b at the tip of irradiation nozzle 2, and an irradiation field P set in an affected part of a patient is irradiated with the beam. Scanning electromagnets 5 and 6 for deflecting the supplied beam L to control scanning are provided within the irradiation nozzle 2. The scanning electromagnets 5 and 6 are configured so that scanning of the beam L can be performed in two directions orthogonal to each other within a plane perpendicular to the direction straight ahead of the supplied beam L. The two directions orthogonal to each other within a plane perpendicular to the direction straight ahead of the beam L are defined as an X-axis direction and a Y-axis direction. The scanning electromagnet 5 is an X-axis scanning electromagnet which deflects the beam L in the X-axis direction, and the scanning electromagnet 6 is a Y-axis scanning electromagnet which deflects the beam L in the Y-axis direction. The beam L is deflected within the plane orthogonal to the direction straight ahead by the scanning electromagnets 5 and 6, and is scanned as a line scanning beam. Two dose monitors 7 and 8 are provided within the irradiation nozzle 2 so as to intersect the course of the beam L. The dose monitors 7 and 8 are provided closer to the irradiation port 2b than the scanning electromagnets 5 and 6, and detect the dose of the passing beam L. The dose monitors 7 and 8 output the detected dose to an electromagnet control unit 9. The electromagnet control unit 9 is provided outside the irradiation nozzle 2, and is electrically connected to the scanning electromagnets 5 and 6, the dose monitors 7 and 8, and a power source 10 which supplies an electric current thereto. Additionally, the electromagnet control unit 9 is electrically connected to an irradiation control unit (scanning control means) 14 which supervises the control relating to the irradiation of the beam L (refer to FIG. 3). The electromagnet control unit 9 outputs detection results of the dose monitors 7 and 8 to the irradiation control unit 14. The electromagnet control unit 9 controls the scanning electromagnets 5 and 6 according to instructions from the irradiation control unit 14 so that scanning of the beam L is performed along a scanning pattern which will be described later. As shown in FIGS. 1 and 2, an irradiation position sensor (irradiation position detecting means) 11 which detects the irradiation position of the beam L is provided within the irradiation nozzle 2. The irradiation position sensor 11 is provided closer to the irradiation port 2b than the dose monitors 7 and 8. The irradiation position sensor 11 is supplied with a high voltage from the power source 10, and includes transmissive multi-strip wires 11A and 11B built into an ionization chamber. 128 lengths of each of the wires 11A and 11B are provided, and the wires 11A and 11B constitute a wire grid which forms a grid shape as seen from the direction straight ahead of the beam L. The wires 11A are arranged so as to extend in the above-described X-axis direction, and the wires 11B are arranged so as to extend in the above-described Y-axis direction. The wires 11A and the wires 11B are arranged so that the heights thereof are different from each other in the direction straight ahead of the beam L. In addition, the number of the wires 11A and 11B is not limited to 128, and may be less than or more than 128. In the wires 11A and 11B configured in this way, their positions within the plane can be expressed as coordinates using respective intersections of the wires 11A and 11B as seen from the direction straight ahead of the beam L. Since charges are generated within the wires 11A and 11B which have received the irradiation of the beam L, the distribution of intersections, i.e., the irradiation position of the beam L, included within an irradiation range of the beam L can be detected by detecting the charges. As shown in FIGS. 1, 3, and 4, the irradiation position sensor 11 is electrically connected to an arithmetic processing circuit unit (stationary time measuring means) 13 via a front end circuit unit 12. The front end circuit unit 12 has 128×2 (256) of each of I/V amplifiers 21, amplifiers 22, and A/D converters 23. The I/V amplifiers 21, the amplifiers 22, and the A/D converters 23 are serially connected to the wires 11A and 11B of the irradiation position sensor 11 in a one-to-one correspondence. If charges are generated in the wires 11A and 11B by the irradiation of the beam L in the front end circuit unit 12, an electric current flows into the I/V amplifier 21 connected to each of the wires 11A and 11B, and is converted into a voltage signal by the I/V amplifier 21. Thereafter, the voltage signal is amplified by the amplifier 22, and the amplified voltage signal is input to the A/D converter 23. Additionally, a signal output from a gate array 34 of an arithmetic processing circuit unit 13 is input to the amplifier 22 through a transceiver 33 and a receiver 27. The A/D converter 23 converts the signal input by the amplifier 22 into a digital signal, and outputs the converted digital signal. The digital signal output by the A/D converter 23 is sent to the gate array 34 of the arithmetic processing circuit unit 13 through a transceiver 24. In addition, in the front end circuit unit 12, signal processing is performed every 0.2 ms, and thereby the detection accuracy of the irradiation position of the beam L is secured. The arithmetic processing circuit unit 13 has the gate array 34, a memory 35, and a processor 36. The gate array 34 has a data register 51 and an arithmetic circuit 52. In the gate array 34, the digital signal output from the A/D converter 23 is input to the data register 51 through a receiver 31. The data registers 51 numbering 128×128 (16,384) are arranged corresponding to respective intersections of the wires 11A and 11B as seen from the direction straight ahead of the beam L. The A/D converters 23 corresponding to each of the wires 11A and the wires 11B are connected to the input terminal of each data register 51. If an intersection of the corresponding wires 11A and 11B is irradiated with the beam L, one digital signal at a time is input from each of the A/D converters 23 connected to the input terminal, thereby satisfying an output condition, and an irradiation position signal is output from the data register 51. The irradiation position signal output from the data register 51 is sent to the arithmetic circuit 52. In the arithmetic circuit 52, the position of an intersection of the wires 11A and 11B which has received the irradiation of the beam L is detected from the irradiation position signal output from the data register 51, and the detection result is temporarily stored as irradiation position information. As such, in the gate array 34, the irradiation position of the beam L is detected in real time on the basis of electric currents output from each of the wires 11A and 11B of the irradiation position sensor 11. The gate array 34 calculates the center of the irradiation position of the detected beam L as the center-of-gravity position. Additionally, the gate array 34 measures the stationary time of the beam L at every calculated center-of-gravity position. Scanning patterns relating to the scanning control of the beam L are stored in the memory 35. The scanning patterns are scanning patterns of the beam L to the irradiation field set in the affected part of a patient, and include information on the irradiation position, stationary time, and locus of the center-of-gravity position of the beam L. The memory 35 outputs a requested scanning pattern to the gate array 34. The gate array 34 compares the scanning pattern with the irradiation position and stationary time of the detected beam L, thereby performing an abnormality existence determination of whether or not scanning control of the beam L is out of the range of the scanning pattern. If it is determined that the scanning control of the beam L is out of the range of the scanning pattern, the gate array 34 outputs an interlock signal to an ICU (Irradiation Control Unit) (interlock control means) 43 of the irradiation control unit 14 via a transceiver 37. The ICU 43 performs the interlock of stopping the irradiation of the beam L compulsorily if an interlock signal is output from the gate array 34. The processor 36 has a command decoder 41 to which a signal from the irradiation control unit 14 is input, and a status encoder 42 which outputs a signal to the irradiation control unit 14. A synchronizing signal for synchronizing with the irradiation control unit 14 is input to the command decoder 41 through a receiver 38. The command decoder 41 outputs the input synchronizing signal to the gate array 34. The irradiation position of the beam L detected by the gate array 34 is input to the status encoder 42. The status encoder 42 outputs the irradiation position of the input beam L to the irradiation control unit 14. Next, abnormality existence determination processing of the scanning control of the beam L in the arithmetic processing circuit unit 13 will be described with reference to the drawings. FIG. 5 is a flow chart showing output processing of actual measurement values in the arithmetic processing circuit unit 13, and FIG. 6 is a flow chart showing output processing of scanning patterns in the arithmetic processing circuit unit 13. FIG. 7 is a flow chart showing abnormality existence determination processing in the arithmetic processing circuit unit 13. As shown in FIG. 5, in the arithmetic processing circuit unit 13 (gate array 34), first, the irradiation position of the beam L is detected by utilizing a digital signal output from the front end circuit unit 12 according to an electric current generated in the irradiation position sensor 11 (Step S1). Thereafter, the center of the irradiation position of the beam L is calculated as the center-of-gravity position (Step S2). When the center-of-gravity position is calculated, the calculated center-of-gravity position is compared with a previously calculated center-of-gravity position, and it is determined whether or not the center-of-gravity position has moved (Step S3). If it is determined that the center-of-gravity position has not moved, the value of Timecount at the center-of-gravity position concerned is increased by one (Step S4). Thereafter, the processing returns to Step S1 from which the respective steps are repeated. In addition, if calculation of the center-of-gravity position is being calculated for the first time, it is determined that the center-of-gravity position has moved. Additionally, the initial value of Timecount is set to “0”. On the other hand, if it is determined that the center-of-gravity position has moved, a change trigger for performing reading of a scanning pattern which will be described later is generated (Step S5). Additionally, Timecount is reset and counting is again started from “0”. Thereafter, the processing returns to Step S1 from which the respective steps are repeated. As shown in FIG. 6, if a change trigger is generated in Step S4 shown in FIG. 5, in the arithmetic processing circuit unit 13 (gate array 34), read-out of a scanning pattern corresponding to the center-of-gravity position is performed from the memory 35 (Step S11). When the read-out of the scanning pattern is performed, processing is ended at this time until a change trigger is generated again. As shown in FIG. 7, if a change trigger is generated in Step S5 shown in FIG. 5, in the arithmetic processing circuit unit 13 (gate array 34), abnormality existence determination of whether or not the center-of-gravity position calculated in Step S2 is within the range of the scanning pattern is performed (Step S21). The scanning pattern to be used in this Step S21 is updated whenever reading of a scanning pattern is performed in Step S11 of FIG. 6. If the center-of-gravity position calculated in Step S2 is within the range of the scanning pattern, that is, if the detected irradiation position coincides with the irradiation position of the scanning pattern, the measured stationary time is less than or equal to the stationary time specified in the scanning pattern, and the locus of movement of the center-of-gravity position is within the range of a locus specified in the scanning pattern, it is determined that scanning control of the beam L is being performed normally. If it is determined that the scanning control of the beam L is being performed normally, the arithmetic processing circuit unit 13 ends the processing. On the other hand, if an actual measurement value is not within the range of the scanning pattern, that is, if a detected irradiation position is different from the irradiation position of the scanning pattern, a measured stationary time exceeds a stationary time specified in the scanning pattern, or the locus of movement of the center-of-gravity position is out of the range of the locus specified in the scanning pattern, it is determined that there is an abnormality in the scanning control of the beam L. Interlock processing is performed if it is determined that there is an abnormality in the scanning control of the beam L (Step S22). In the interlock processing, an interlock signal is generated, and output to the ICU 43 of the irradiation control unit 14, and thereafter, the subsequent is ended. The ICU 43 to which the interlock signal has been output performs the interlock of stopping the irradiation of the beam L compulsorily. Next, the state transition in the line scanning apparatus 1 will be described with reference to the drawings. FIG. 8 is a state transition diagram of the line scanning apparatus. As shown in FIG. 8, the line scanning apparatus 1 is transferred to an idle state when operation preparation is ended after being activated (Step S31). In the idle state, it is first determined whether or not an irradiation completion signal has been input by a medical practitioner, such as a doctor, or a completion program (Step S32). If it is determined that the irradiation completion signal has been input, the line scanning apparatus 1 ends its operation. On the other hand, if it is determined that the irradiation completion signal has not been input, it is subsequently determined whether or not an irradiation start signal has been input (Step S33). If it is determined that an irradiation start signal has not been input, the processing returns to Step S32 where the idle state is continued. If it is determined that the irradiation start signal has been input, the processing is transferred to a standby state (Step S34). When the processing is transferred to the standby state, it is determined whether or not scanning control of the beam L to the irradiation field has ended (Step S35). If it is determined that the scanning control of the beam L to the irradiation field has ended, the processing returns to Step S31 and is transferred to the idle state. On the other hand, if it is determined that the scanning control of the beam L to the irradiation field has not ended, the processing is transferred to a hold state where the irradiation position of the beam L is held after 0.2 ms has elapsed since the transition to the standby state (Step S36). Thereafter, the center-of-gravity position in the held irradiation position is calculated, the counting of the stationary time at the center-of-gravity position is started, and the processing is transferred to a stationary time determination state where whether or not this stationary time is within the range of the scanning pattern is determined (step S37). If it is determined that the stationary time is not within the range of the scanning pattern, the processing is transferred to Step S41. If it is determined that the stationary time is within the range of the scanning pattern, it is determined whether or not the center-of-gravity position has moved (Step S38). In Step S38, if it is determined that the center-of-gravity position has not moved, the counting of the stationary time proceeds, and the processing returns to Step S38 where it is determined whether or not the new stationary time is within the range of the scanning pattern. On the other hand, if it is determined that the center-of-gravity position has moved, the processing is transferred to a position determination state where whether or not the irradiation position of the detected beam L is within the range of the scanning pattern is determined (Step S39). In Step S39, if it is determined that the irradiation position of the beam L is not within the range of the scanning pattern, the processing shifts to Step S41. On the other hand, if it is determined that the irradiation position of the beam L is within the range of the scanning pattern, the processing is transferred to a locus determination state where whether or not the locus of the center-of-gravity position is within the range of the scanning pattern is determined (Step S40). In Step S40, if it is determined that the locus of the center-of-gravity position is within the range of the scanning pattern, the processing returns to Step S34 and is transferred to the standby state. On the other hand, if it is determined that the locus of the center-of-gravity position is not within the range of the scanning pattern, the processing is transferred to Step S41. In Step S41, it is determined that there is an abnormality in the scanning control as an actual measurement value relating to the scanning control of beam L is not within the range of the scanning pattern, and the processing is transferred to the interlock state of stopping the irradiation of the beam L compulsorily. If the processing is transferred to the interlock state, it is determined whether or not a release signal has been input (Step S42). If it is determined that the release signal has not been input, the interlock state is continued, and the determination of Step S42 is again performed after a predetermined time. On the other hand, if it is determined that the release signal has been input, the processing returns to Step S31 and is transferred to the idle state. Next, an example in a case where it is determined that there is an abnormality in the scanning control of the beam L will be described with reference to the drawings. As shown in FIG. 9A, a case where scanning control of the beam L is performed in the order of an arrow A, an arrow B, and an arrow C within the irradiation field N will be considered. As for the actual measurement values and scanning patterns in this case, data on the loci of center-of-gravity positions (X-axis, Y-axis) and stationary times (Time) in the respective center-of-gravity positions is shown in FIG. 9B. In addition, in FIG. 9A, a case where not the intersections of the wires 11A and 11B but an irradiation position corresponding to the inside of a frame is detected will be described for clarification of description. As shown in FIGS. 9A and 9B, as for the scanning between the arrow A in which the center-of-gravity position of the beam L moves to (5, 2) from (2, 2) and the arrows B in which the center-of-gravity position moves to (3, 3) from (5, 3), it is determined that actual measurement values of the loci of the center-of-gravity positions and the stationary time are within the range of the scanning patterns, and the scanning control of beam L is being performed normally. Thereafter in the scanning of the arrow C, the center-of-gravity position (2, 4) which is an actual measurement value is out of the center-of-gravity position (3, 4) in a scanning pattern. Therefore, it is determined that there is an abnormality in the scanning control of the beam L. At this time, in the line scanning apparatus 1, the interlock processing is performed and the scanning of the beam L is compulsorily stopped. Thus, erroneous irradiation of the beam L is prevented further. According to the line scanning apparatus 1 described above, the irradiation position of the line scanning beam L is detected, the stationary time corresponding to the center-of-gravity position of the irradiation position is measured, and scanning control of the line scanning beam L is performed by utilizing these results, so that irradiation of the line scanning beam L to an erroneous position or excessive irradiation of the line scanning beam can be more reliably prevented, and thereby the reliability of the line scanning apparatus 1 can be improved. Additionally, in the line scanning apparatus 1, if the line scanning beam L is radiated to an erroneous position, or is excessively radiated so as to exceed a predetermined time, the erroneous irradiation of the line scanning beam can be more reliably prevented by performing the interlock control of stopping the irradiation of the line scanning beam. The invention is not limited to the above-described embodiment. For example, the line scanning apparatus 1 may adopt an aspect in which feedback control of scanning of a line scanning beam is performed by utilizing a detected irradiation position and a measured stationary time. Specifically, the line scanning apparatus may adopt an aspect where reset control of a scanning pattern is performed so that an erroneous irradiation is not caused in a part where the erroneous irradiation has occurred once when an irradiation field is irradiated a plurality of times with a beam with suppressed intensity in order to reduce risks due to erroneous operation of a line scanning beam. Additionally, the line scanning apparatus may also adopt an aspect where, if the center-of-gravity position of a line scanning beam has moved, the stationary time and center-of-gravity coordinates before and after the movement are stored in the arithmetic circuit 13 (gate array 34), the traveling speed of the line scanning beam is calculated using the stationary time and center-of-gravity coordinates before and after the movement, and beam control is performed by feed back of the calculated traveling speed to the electromagnet control unit 9. Additionally, although the time until the center-of-gravity position of a line scanning beam moves is measured as the stationary time in the above-described embodiment, an aspect may be adopted where the time until not the center-of-gravity position but the irradiation position changes is measured as the stationary time. Additionally, the line scanning apparatus 1 related to the embodiment of the invention can also be applied to equipment or apparatuses other than the particle beam therapy facility. It should be understood that the invention is not limited to the above-described embodiment, but may be modified into various forms on the basis of the concept of the invention. Additionally, the modifications are included in the scope of the invention.
053655540	claims	1. An instrumentation probe for use in the on-line measurement and recording of one or more physical parameters within a nuclear reactor fuel channel, without connection to external instrumentation, said instrumentation probe comprising: an elongate support frame for being mounted within the fuel channel, and measuring and recording means mounted on the frame, said measuring and recording means comprising 2. An instrumentation probe according to claim 1, wherein the speed reducing mechanism is a gear reduction train having an input shaft and an output shaft, the recording chart comprising a rotary drum mounted on the output shaft. 3. An instrumentation probe according to claim 1, wherein the support frame is configured as a cylindrical cage having perforate end plates. 4. An instrumentation probe according to claim 3, wherein the support frame is configured to simulate a fuel bundle of the reactor. 5. An instrumentation probe according to claim 4, wherein the cylindrical cage comprises an array of fuel pencils extending longitudinally between the end plates, the array of fuel pencils being distributed symmetrically around a longitudinal axis and defining an axially extending internal space wherein said measuring and recording means are mounted. 6. An instrumentation probe according to claim 5, wherein at least some of the fuel pencils are dummy pencils.
	summary
	summary
	description	The present invention relates to a device used as a target for producing a radioisotope, such as 18F, by irradiating with a beam of particles a target material that includes a precursor of said radioisotope. One of the applications of the present invention relates to nuclear medicine, and in particular to positron emission tomography. Positron emission tomography (PET) is a precise and non-invasive medical imaging technique. In practice, a radiopharmaceutical molecule labelled by a positron-emitting radioisotope, in situ disintegration of which results in the emission of gamma rays, is injected into the organism of a patient. These gamma rays are detected and analysed by an imaging device in order to reconstruct in three dimensions the biodistribution of the injected radioisotope and to obtain its tissue concentration. Fluorine 18 (T1/2=109.6 min) is the only one of the four light positron-emitting radioisotopes of interest (11C, 13N, 15O, 18F) that has a half-life long enough to allow use outside its site of production. Among the many radiopharmaceuticals synthesised from the radioisotope of interest, namely fluorine 18, 2-[18F]fluoro-2-deoxy-D-glucose (FDG) is the radio-tracer used most often in positron-emission tomography. In addition to the morphology imaging, PET performed with 18F-FDG allows to determine the glucose metabolism of tumours (oncology), myocardium (cardiology) and brain (psychology). The 18F radioisotope in its anionic form (18F−) is produced by bombarding a target material, which in the present case consists of 18O-enriched water (H218O), with a beam of charged particles, more particularly protons. To produce said radioisotope, it is common practice to use a device constituting an irradiation cell comprising a cavity “hollowed out” in a metal part and intended to house the target material used as precursor. This metal part is usually called an insert. The cavity in which the target material is placed is sealed by a window, called “irradiation window” which is transparent to the particles of the irradiation beam. Through the interaction of said particles with the said target material, a nuclear reaction occurs which leads to the production of the radioisotope of interest. The beam of particles is advantageously accelerated by an accelerator such as a cyclotron. Because of an ever increasing demand for radioisotopes, and in particular for the 18F radioisotope, efforts are made to increase the yield of the above mentioned nuclear reaction. This is done either by modifying the energy of the beam of particles (protons), making use of the dependence of thick target yield on the particle energy, or by modifying the intensity of the beam, thereby modifying the number of accelerated particles striking the target material. However, the power dissipated by the target material irradiated by the accelerated particle beam limits the intensity and/or the energy of the particle beam that is being used. This is because the power dissipated by a target material is determined by the energy and the intensity of the particle beam through the following equation:P (watts)=E (MeV)×I(μA)where: P=power expressed in watts; E=energy of the beam expressed in MeV; and I=intensity of the beam expressed in μA. In other words, the higher the intensity and/or the energy of the particle beam, the higher will be the power to be dissipated by a target material. It will consequently be understood that the energy and/or the intensity of the beam of accelerated charged particles cannot be increased without rapidly generating, within the cavity of the production device, and at the irradiation window, excessive pressures or temperatures liable to damage said window. Moreover, in the case of 18F radioisotope production, given the particularly high cost of 18O-enriched water, only a small volume of this target material, used as a precursor material, at the very most a few milliliters, is placed in the cavity. Thus, the problem of dissipating the heat produced by the irradiation of the target material over such a small volume constitutes a major problem to be overcome. Typically, the power to be dissipated for a 18 MeV proton beam with an intensity of 50 to 150 μA is between 900 W and 2700 W, and this in a volume of 18O-enriched water of 0.2 to 5 ml, and for irradiation times possibly ranging from a few minutes to a few hours. More generally, given this problem of heat dissipation by the target material, the irradiation intensities for producing radioisotopes are currently limited to 40 μA for an irradiated target material volume of 2 ml in a silver insert. Current cyclotrons used in nuclear medicine are however theoretically capable of accelerating proton beams with intensities ranging from 80 to 100 μA, or even higher. The possibilities afforded by current cyclotrons are therefore under-exploited. Solutions have been proposed in the prior art for overcoming the problem of heat dissipation by the target material in the cavity within the radioisotope production device. In particular, it has been proposed to provide means for cooling the target material. Accordingly, document BE-A-1011263 discloses an irradiation cell comprising an insert made of Ag or Ti, said insert comprising a hollowed-out cavity sealed by a window, in which cavity the target material is placed. The insert is placed in co-operation with a ‘diffusor’ element which surrounds the outer wall of said cavity so as to form a double-walled jacket allowing the circulation of a refrigerant for cooling said target material. For improving heat flow out of the cavity, a cavity having a wall as thin as possible is desirable. However, when silver is used as material for the cavity, wall porosity becomes a problem when wall thickness is smaller than 1.5 mm. The materials for manufacturing the device according to the present invention have to be selected in a cautious way. In particular, the choice of the insert material is particularly important. It is indeed necessary to avoid the production of undesirable by-products during irradiation which would lead to a remaining activity. By way of example, it is necessary to avoid the production of such radioisotopes that disintegrate by high-energy gamma particle emission and make any mechanical intervention on the target difficult due to radiosafety problems. Indeed, the overall activity of the insert measured after irradiation and total emptying of said insert has to be as low as possible. Titanium is chemically inert but under proton irradiation produces 48V having a half-life of 16 days. Consequently, in the case of titanium, should a target window break, its replacement would pose serious problems for the maintenance engineers who would be exposed to the ionizing radiation. In addition, when choosing the type of material for the inserts of the device according to the invention, another key parameter is its thermal conductivity. Thus, silver is a good conductor but does have the drawback that, after several irradiation operations, it forms silver compounds that can block the emptying system. It would be ideal to use niobium for the insert, this material having a thermal conductivity two and a half times higher than titanium (53.7 W/m/K for Nb and 21.9 W/m/K for Ti), though eight times lower than silver (429 W/m/K). Niobium is chemically inert and produces few isotopes of long half-life. Therefore, niobium is a good compromise. However, niobium is a difficult material to use in an insert of complex design, as it is difficult to machine. A built-up edge may occur on the tools, leading to high tool wear. Eventually, the tool may break. The use of electrical discharge machining is not a solution either: the electrodes wear out without shaping the piece to be machined. In particular, the insert described in document BE-A-1011263 is of a complex structure, which would be difficult to produce in niobium. Also, using prior art insert forms and materials, it is impossible to produce a more elongated insert, which would be beneficial as it would provide a larger surface for the thermal exchange. Tantalum is also a material having interesting properties, but, which is, like niobium, difficult to machine. Tantalum has a thermal conductivity (57.5 W/m/K) slightly higher (better) than Niobium. Document WO02101757 is related to an apparatus for producing 18F-Fluoride, wherein an elongated chamber is present, for containing the gaseous or liquid target material which is to be irradiated. The chamber can be made from niobium. However, this apparatus does not comprise what is defined as an ‘insert’, a separate part comprising the cavity, which is to be introduced in the irradiation cell. The apparatus of WO02101757 comprises several parts assembled together, but there is no distinction between the cell and the insert. The same is true for the irradiation devices described in U.S. Pat. No. 5,917,874, US2001/0040223 and U.S. Pat. No. 5,425,063. The closest prior art is therefore the BE1011263-patent. The invention aims to provide a better solution for irradiation devices of the type described in that document, namely devices comprising an irradition cell, and an insert as defined above. A particular aim of the present invention is to provide an irradiation cell having an insert made at least partially of niobium or tantalum and designed in order to provide internal cooling means. The present invention is related to an irradiation cell and insert such as described in the appended claims. The invention is related to an irradiation cell, for the purpose of containing, inside a cavity, the material to be irradiated for producing radioisotopes. The cell comprises internal cooling means for cooling the cavity, and a metallic insert comprising the cavity. The inventive aspect of the cell is that the insert is made of at least two parts, assembled together, and made of different materials. The part which comprises the cavity is designed in such a way that it is easy to produce in any material, so that it can be produced for instance in niobium, or in tantalum, which are the most suitable materials for irradiation purposes. The other part or parts of the insert can then be produced in another material. The invention is equally related to the metallic insert per se. A preferred embodiment of the irradiation cell 1 is disclosed in the accompanying drawings. FIG. 1 is a 3-d view of the irradiation cell assembly, including the connections for the cooling medium. The irradiation cell comprises the target body 1 and the insert 2. The target body is coupled to a cooling medium inlet 4 and an outlet 5. The assembled irradiation cell can be seen in FIG. 2, where once more the target body 1 is visible. The insert 2 comprises a first metallic part 8 which comprises the cavity 7, wherein the target material is to be placed. The insert equally comprises a second metallic part 9 which surrounds the cavity 7, so as to form a channel for guiding a cooling medium around the cavity. A means for supplying a cooling medium is present in the form of a tube 6, which is to be connected to the cooling inlet. At the end of this tube, a ‘diffusor’ element 3 is mounted which is essentially an element which is in connection with the supply tube, and arranged to surround the cavity in a manner to form a return path for said cooling medium between said diffusor and said second part. According to the preferred embodiment of the present invention, the insert 2 is thus made of two metallic parts 8 and 9, assembled together by bolts 10. Real metal to metal contact and the presence of O-ring 30 and 32 provides an essentially perfect seal between the two parts 8 and 9, and between part 9 and target body 1, respectively, thereby preventing the escape of cooling water outside the irradiation cell. The first part 8 comprises the cavity 7. Because of its simple structure, this part 8 is easy to produce, meaning that it can be produced from the most suitable material for irradiation purposes, in particular niobium. The second metallic part 9 is itself bolted to the target body 1 by bolts 11. Because this second part is not in direct contact with the target material, it can be produced in another material, such as stainless steel or any conventional material. Being made of two parts, the insert of the invention allows the cavity-wall to be produced in the ideal material, niobium or tantalum, without encountering the practical problem of producing a complicated niobium or tantalum structure. Also, this design would allow to produce an insert with a more elongated cavity 7 in niobium or tantalum, than would be possible in existing inserts. In particular, a cavity with a length of up to 40 mm can be produced in an insert according to the invention. The cavity 7 is closed (sealed) by an irradiation window transparent to the accelerated particle beam. The window is not shown on FIG. 2. It is placed against the structure shown, and sealed off by the O-ring 40. The window is advantageously made of Havar and between 25 and 200 μm thick, preferably between 50 and 75 μm thick. FIG. 3 shows section and perspective views of the first part 8 according to the preferred embodiment. FIG. 4 shows the same for the second part 9. The part 8 essentially comprises a flat, ring shaped circular portion 16, having an inner and outer circular edge (50,51 respectively). A cylindrical portion 17 rises up perpendicularly from the inner edge of the flat portion 16, with a hemispherical portion 18 on top of the cylindrical portion 17, closing off the cavity from that side. A cavity having an inner diameter of 11.5 mm, and an overall length of 25 mm, produces a 2 ml volume for containing the target material. The length of the cavity may be adapted according to the desired volume. A larger outer surface allows a better thermal exchange between the target material in the cavity and cooling means, at the cost of more target material. Using the two-part design of the invention, cavities having a first part 8 with an overall length of 50 mm or even higher can be produced, even when it is difficult to machine materials such as niobium and tantalum. Holes 19 are present in the flat portion, to bolt the first part 8 to the second part 9. Niobium and tantalum having a lower thermal conductivity than silver inserts, it is desirable to have the cylindrical 17 and hemispherical 18 portions as thin as possible, in order to improve the thermal exchange between target material in cavity 7 and cooling water. A thickness of 0.5 mm has been found acceptable to obtain the required heat exchange, without suffering from porosity problems. It has been found by the inventors of the present invention that obtaining such a thin wall, especially for an insert having a great length, is only obtainable with a two-part insert. It has also been found by the inventors that the irradiation cell according to the invention produces a high yield in the radioisotope of interest, even when the cavity is only partially filled with the target material before irradiation start. Satisfactory yields are obtained when filling ratio, i.e. ratio of target material volume inserted in cavity over cavity internal volume are below 50%, preferably about 50%. This is different than prior art devices, in particular the one shown in BE10112636. Using the insert of that document, the cavity is necessarily shorter due to the machining difficulty described above. A consequence of this is that these short cavities need to be filled to a maximum, otherwise too much of the radiation energy is lost. If one is able to use a longer cavity, this is beneficial for the heat exchange, as already stated, but another consequence is that a good irradiation efficiency can be obtained even with a filling rate of about 50%. This is because a half-filled long cavity allows for more space to be filled with vapour after irradiation has started, and a longer distance over which this vapour can react with the proton beam. Therefore, the 50% filling rate is directly related to the longer cavity and thus to the two-part construction of the insert. As seen in FIG. 4, part 9 is essentially a hollow cylinder, comprising two flat sides 52, 53 essentially perpendicular to a cylindrical circumferential side 54. The part 9 comprises holes for bolting it at one flat side 53 against the first part 8 and by the other flat side 52 to the target body 1. The flat side 53 which is to be put against the first part 8, is equipped with a protruding ridge 26, which is to fit into a groove 27 around the circumference of the first part 8. This allows a perfect coaxial positioning of parts 8 and 9 with respect to each other. Other shapes of parts 8 and 9 or additional sub-parts of the insert may be devised according to the invention which is related to the broader concept of an insert made of more than one solid part made of different materials. In the preferred embodiments shown, the part 9 has two diametrically opposed openings 20, which correspond, when the insert is assembled, to two holes 21 in the first part 8. These holes 21 give access to two tubes 22 in the interior of the part 8, which lead up to the cavity 7. On the assembled irradiation cell, external tubes 23 can be mounted by hollow bolts 24, through seals 25, for connection to the openings 20 and tubes 22. The two tubes 23 can then be coupled to a circuit for circulating fluid material to be irradiated in the cell, or for filling the cell before irradiation and emptying the cell after irradiation. Furthermore, cooling means using liquid helium may be provided to cool the irradiation window. Further in the preferred embodiment shown in the accompanying drawings, the sealing between parts 8 and 9 is obtained by an O-ring 30 accommodated in a circular groove 31 in the second part 9. Another O-ring 32 seals off the connection between the second part 9 and the target body 1. Further O-rings 33 are present in grooves surrounding the outlets 20 of the tubes 23 for filling and emptying the irradiation cell 7, thereby preventing the escape of target material outside of the cavity 7. These O-rings are especially important because they may come in contact with the target material which may comprise chemically or nuclear active material, and must withstand the pressure inside the cavity 7 during irradiation. This pressure may be up to 35 bar or higher. The material for the O-rings is preferably Viton. Due to the metal-to-metal contact, the insert of the invention is designed so that there is virtually no contact between the target material (18O-enriched water) and the O-rings. No chemical contamination coming from Viton degradation is possible in this design. According to an alternative embodiment, there are no O-rings between the parts 8 and 9 of the insert, but a gold foil is inserted between said parts. This foil ensures the perfect seal for the target material inside the cavity. In yet another embodiment, the connection between parts 8 and 9 is not obtained by bolts, but by welding. By selecting an appropriate material for the first part (8) of the insert, such as niobium or tantalum which have a very low chemical reactivity with the chemicals present in the cavity 7, especially with 18F-, one obtains a virtually permanent hard-wearing target. In addition, by using such inert material, no products that could clog the tubes in which the target material flows are dissolved into the target material.
	abstract	In a submersible ultrasonic cleaning system for use in highly radioactive environments (e.g., cleaning radiated nuclear fuel assemblies), a bond between energy producing transducers and an radiating wall is strengthened with a polyurethane adhesive such as Permabond PT326, or 3M DP-190 adhesive. In various diagnostic tests, one or more of the transducers are operated in an energy-transmitting mode while one or more other transducers are operated in an energy-detecting mode to detect a weakened transducer/wall bond and/or acoustic conditions of the working fluid.
052992446	claims	1. A fuel assembly comprising a plurality of fuel rods containing fissile material being arranged at predetermined pitches in first and second directions and being arranged in triangle lattices, a plurality of water rods group arranged among said fuel rods, an upper tie plate and a lower tie plate which respectively supports each of an upper end and a lower end of the fuel rod or a water rod in the water rods group, and fuel spacers for maintaining intervals between the fuel rods, each of the water rods group including no fuel rod and with a plurality of water rods which are arranged adjacent to each other in triangle lattices having substantially the predetermined pitches of the fuel rods, the outer diameter of the water rod being smaller than the predetermined pitches, and the water rods groups being arranged not adjacent to each other and being surrounded with the fuel rods. a fraction of the number of said water rods to a sum of the number of said fuel rods and the number of said water rods included in the fuel assembly is at least 10%. said fuel rods comprise first fuel rods and second fuel rods, the second fuel rods having a shorter length in an axial direction than the first fuel rods. said fuel rods comprise first fuel rods and second fuel rods, the second fuel rods having a shorter length in an axial direction than the first fuel rods. said second fuel rods are located not adjacently to said water rods group, and are surrounded with said first fuel rods. 2. A fuel assembly as claimed in claim 1, wherein 3. A fuel assembly as claimed in claim 1, wherein 4. A fuel assembly as claimed in claim 2, wherein 5. A fuel assembly as claimed in claim 3, wherein
	summary
	claims	1. An imaging optical unit for EUV projection lithography for imaging an object field in an object plane into an image field in an image plane, the imaging optical unit comprising:a plurality of mirrors for guiding imaging light from the object field to the image field;an aperture stop, which is tilted by at least 1° relative to a normal plane which is perpendicular to an optical axis,wherein the aperture stop is configured with a circular stop contour,wherein the aperture stop is arranged in such a way that the following applies to mutually perpendicular planes: a deviation of a numerical aperture NAx measured in one of these planes from a numerical aperture NAy measured in the other one of these two planes is less than 0.003, averaged over the field points of the image field. 2. The imaging optical unit of claim 1, wherein the stop is arranged at a distance from, or tilted relative to, a plane, in which coma rays of the imaging light from spaced apart field points intersect. 3. The imaging optical unit of claim 1, wherein the aperture stop is arranged at a distance from, or tilted relative to, a plane, in which chief rays of the imaging light from spaced apart field points intersect. 4. The imaging optical unit of claim 1, wherein a centre of the aperture stop is at a distance from a reference axis of the imaging optical unit. 5. The imaging optical unit of claim 1, wherein the aperture stop is tilted about a tilt axis which is perpendicular to a tilt normal plane,which contains an object displacement direction for an object arrangeable in the object plane andwith at least one field plane being perpendicular thereto. 6. The imaging optical unit of claim 1, wherein the tilt angle is less than 20°. 7. The imaging optical unit of claim 1, wherein the aperture stop is tilted in such a way that an angle of a stop normal relative to a chief ray of a central field point becomes smaller in comparison with an angle of the optical axis relative to the chief ray of the central field point. 8. The imaging optical unit of claim 1, wherein the aperture stop is tilted in such a way that an angle of a stop normal relative to a chief ray of a central field point becomes larger in comparison with an angle of the optical axis relative to the chief ray of the central field point. 9. The imaging optical unit of claim 1, wherein the aperture stop is configured as a planar stop. 10. The imaging optical unit of claim 1, wherein at least one of the mirrors has a reflection surface embodied as a free-form surface. 11. The imaging optical unit of claim 1, further comprising a tilt drive, to which the aperture stop is connected for the purposes of tilting. 12. An optical system, comprising:the imaging optical unit of claim 1; andan illumination optical unit for illuminating the object field with illumination light or imaging light. 13. A projection exposure apparatus, comprising:the optical system of claim 12; anda light source for generating EUV illumination light or imaging light;an object holder with an object displacement drive; anda substrate holder for holding a wafer, arrangeable in the image field, with a wafer displacement drive. 14. A method for producing a structured component, comprising:providing a reticle and a wafer;projecting a structure on the reticle onto a light-sensitive layer of the wafer with the aid of the projection exposure apparatus of claim 13; andgenerating a structure on the wafer.
	summary
	summary
	description	The present application is a continuation of, and claims benefit under 35 USC 120 to, international application PCT/EP2014/066072, filed Jul. 25, 2014, which claims benefit under 35 USC 119 of German Application No. 10 2014 208 770.8, filed May 9, 2014, 10 2013 214 770.8, filed Jul. 29, 2013, and 10 2014 203 190.7, filed Feb. 21, 2014. The entire disclosure of international application PCT/EP2014/066072 is incorporated by reference herein. The disclosure relates to a projection optical unit for imaging an object field into an image field. Furthermore, the disclosure relates to an optical system including such a projection optical unit, a projection exposure apparatus including such an optical system, a method for producing a microstructured or nanostructured component using such a projection exposure apparatus and a microstructured or nanostructured component produced by this method. Projection optical units are known from DE 10 2012 202 675 A1, DE 10 2009 011 328 A1, U.S. Pat. No. 8,027,022 B2 and U.S. Pat. No. 6,577,443 B2. An illumination optical unit for a projection exposure apparatus is known from DE 10 2009 045 096 A1. The disclosure seeks to provide a projection optical unit which exhibits a well-corrected imageable field with, at the same time, a high imaging light throughput. In one aspect, the disclosure provides a projection optical unit for imaging an object field into an image field. The projection optical unit includes a plurality of mirrors for guiding imaging light from the object field to the image field. At least two of the mirrors are embodied as mirrors arranged directly behind one another in the beam path of the imaging light for grazing incidence with an angle of incidence of the imaging light which is greater than 60°. In one aspect, the disclosure provides projection optical unit for imaging an object field in an image field. The projection optical unit includes a plurality of mirrors for guiding imaging light from the object field to the image field. At least one mirror is embodied as a mirror for grazing incidence with an angle of incidence of the imaging light which is greater than 60°. The projection optical unit has two different imaging scales (βx, βy) in two different directions which span the image field. According to the disclosure, it was discovered that two mirrors, arranged directly behind one another, for grazing incidence within the projection optical unit lead to the possibility of designing a projection optical unit with a high imaging light throughput, which is uniform over the whole field to be imaged, wherein, also at the same time, degrees of freedom are provided for correcting the image in the image field via the mirrors with grazing incidence. The mirrors of the projection optical unit can carry the coatings which increase the imaging light reflectivity. Ruthenium and/or molybdenum can be used as coating materials for these coatings. The mirrors for grazing incidence can have a reflectivity which lies in the range between 75 and 95% and which, in particular, can be at least 80%. The mirrors for grazing incidence can have a reflectivity which depends linearly on the angle of incidence. Such a linear dependence can be compensated for by the use of at least one further mirror for grazing incidence, which likewise has a corresponding linear dependence of the reflectivity on the angle of incidence. The projection optical unit is suitable for EUV wavelengths of the imaging light, in particular in the range between 5 nm and 30 nm. The angle of incidence of the imaging light on the mirrors for grazing incidence can be greater than 65°, can be greater than 70°, can be greater than 72°, can be greater than 75°, can be greater than 80° or can also be greater than 85°. The projection optical unit can be embodied for imaging a portion of a reflecting reticle. To this end, a chief ray of a central object field point can include an angle with a normal of the object plane which is greater than 3° and for example equals 5.5°. One of the at least two mirrors for grazing incidence can be the first mirror of the projection optical unit downstream of the object field in the imaging beam path. The mirrors for grazing incidence can have reflection surfaces which deviate from a plane surface and can, in particular, have an image aberration-correcting surface form. The reflection surfaces of the mirrors for grazing incidence can be embodied as aspherical surfaces or else as free-form surfaces without rotational symmetry. An intermediate image plane can be arranged in the region of a reflection on a mirror for grazing incidence. This leads to an advantageous constriction of an imaging light beam in the region of the mirror for grazing incidence and therefore avoids the latter requiring an undesirably large reflection surface. The projection optical unit can be embodied as a catoptric optical unit. The projection optical unit can include at least one mirror with a passage opening for the illumination light. The projection optical unit can be embodied as an obscured optical unit. Alternatively, the projection optical unit can also be embodied in such a way that the reflection surfaces of all mirrors of the projection optical unit are used throughout. The projection optical unit can be embodied as a non-obscured optical unit. An x/y aspect ratio of a reflection surface optically impinged upon with illumination light, i.e. a used reflection surface, of at least one mirror of the projection optical unit can be less than 1, can be less than 0.8, can equal 0.7, can be less than 0.7, can be less than 0.6 and can equal 0.5. Here, the y-coordinate lies in a plane of incidence of the respectively observed mirror. The x-coordinate lies perpendicular to the plane of incidence of the respectively observed mirror. A scanning direction, in which an object to be imaged and/or a substrate, on which imaging takes place, is displaced, can also extend along the y-coordinate. An x/y aspect ratio of a reflection surface optically impinged upon with illumination light, i.e. a used reflection surface, of at least one mirror of the projection optical unit can be greater than 1, can equal 2, can be greater than 2, can equal 2.5, can be greater than 2.5, can be greater than 3, can be greater than 4, can be greater than 5, can be greater than 6, can equal 7.5, can be greater than 10 and can equal 15. The projection optical unit can have a sequence of mirrors in which, in addition to at least one GI mirror pair, i.e. two mirrors for grazing incidence arranged directly behind one another in the beam path, there is also a single GI mirror. The projection optical unit can have three successive GI mirrors. The projection optical unit can include at least one mirror which has the embodiment of a saddle surface, i.e. which has positive refractive power in one plane and negative refractive power in a plane perpendicular thereto. The projection optical unit can have a plurality of such saddle mirrors. In some embodiments, the projection optical unit includes exactly two mirrors for grazing incidence. Exactly two mirrors for grazing incidence were found to be particularly suitable for the projection optical unit. In some embodiments, an object plane in which the object field is arranged has an angle different from 0° with an image plane in which the image field is arranged. Such an angle between the object plane and the image plane enables a particularly compact guidance of the imaging light beam path or imaging beam path. This angle can be greater than 1°, can be greater than 2°, can be greater than 3°, can be greater than 5°, can be greater than 7°, can be greater than 10°, can be greater than 20°, can be greater than 30° and can equal 39°. In some embodiments, the projection optical unit includes exactly four mirrors for grazing incidence. Exactly four mirrors for grazing incidence were also found to be particularly suitable. In some embodiments, the four mirrors for grazing incidence are respectively, in a pairwise manner, arranged directly behind one another in the beam path of the imaging light. Such a pairwise arrangement of the mirrors for grazing incidence was found to be suitable for compensating an angle of incidence-dependent reflection. At least one mirror for normal incidence can lie between the pairs of mirrors for grazing incidence. The pairs of mirrors for grazing incidence can be arranged in such a way that a deflecting effect of the two mirrors arranged in succession is summed, i.e. that the angles of reflection are added. Such an embodiment enables a compensation of an angle of incidence-dependent reflectivity on the mirrors for grazing incidence. Alternatively, it is possible to assign to a mirror for grazing incidence a compensation mirror for grazing incidence at a different point in the beam path of the imaging light through the projection optical unit, wherein individual rays which are incident on the mirror for grazing incidence with a relatively large angle of incidence are accordingly incident on the compensation mirror with a smaller angle of incidence, and vice versa. A further mirror for grazing incidence and/or a mirror for normal incidence can be arranged between a mirror with grazing incidence and the compensation mirror assigned thereto. To the extent that more than two mirrors for grazing incidence are provided in the projection optical unit, the compensation effect of a compensation mirror may also apply to more than one of the other mirrors for grazing incidence. Thus, for example, in the case of the three mirrors for grazing incidence, it is possible to provide one compensation mirror for grazing incidence which compensates the angle of incidence dependence of the reflection for two further mirrors for grazing incidence. In some embodiments, the projection optical unit includes at least two mirrors for normal incidence with an angle of incidence of the imaging light which is less than 45°. Such embodiments were found to be particularly suitable for satisfying boundary conditions placed on a projection optical unit. The at least two mirrors for normal incidence can be impinged upon with an angle of incidence of the imaging light which is less than 40°, which is less than 35°, which is less than 30°, which is less than 25°, which is less than 20° and which can be even smaller. In some embodiments, the projection optical unit includes four mirrors for normal incidence with an angle of incidence of the imaging light which is less than 45°. Four mirrors for normal incidence lead to the option of a projection optical unit with particularly good image correction. An image-side numerical aperture of the projection optical unit can be at least 0.4 or 0.5 or 0.6. Such a projection optical unit enables a particularly high resolution. In some embodiments, the projection optical unit has an overall reflectivity, emerging as the product of the reflectivities of all mirrors of the projection optical unit, that is greater than 9%. Such an overall reflectivity of the projection optical unit can be 9.75%, can be greater than 10%, can be greater than 11%, can equal 11.97%, can be greater than 12% and can, in particular, equal 12.2%. Greater overall reflectivities are also possible, in particular depending on the embodiment of reflection-increasing coatings on the mirrors. In one aspect, the disclosure provides an EUV projection optical unit for imaging an object field in an image field. The EUV projection optical unit includes a plurality of mirrors for guiding imaging light from the object field to the image field. The EUV projection optical unit has an image-side numerical aperture of at least 0.4. An overall reflectivity of the projection optical unit, emerging as the product of the reflectivities of all mirrors of the projection optical unit is greater than 7%. Such an EUV projection optical unit disclosed herein simultaneously has a high structure resolution and a high throughput for the EUV imaging light. That is to say, little used light is lost during the projection, which in turn reduces an exposure duration and therefore increases the wafer throughput of a projection exposure apparatus equipped with such an EUV projection optical unit. The overall reflectivity can be greater than 8%, can be greater than 9%, can be greater than 10% or can be even greater. The anamorphic optical unit has different imaging scales for different field coordinates, in particular for orthogonal field coordinates. Here, an absolute reduction factor of the projection optical unit is referred to as imaging scale. By way of example, a projection optical unit reducing by a factor of 4 accordingly has an imaging scale of 4. Then, a larger imaging scale means that there is an increase in the reduction factor. Thus, within this meaning, a projection optical unit with a reduction by a factor of 8 has a larger imaging scale than a projection optical unit with a reduction by a factor of 4. The anamorphic optical unit can have a direction-dependent, i.e. field coordinate-dependent, object-side numerical aperture. It was identified that if the object-side numerical aperture increases, the object-side chief ray angle desirably is enlarged, possibly leading to shadowing effects by the absorber structure and to problems with the layer transmission, in particular to strong apodization effects by the reticle coating. It was identified further that, via an anamorphic imaging optical unit, in particular via an anamorphic imaging projection lens, a reticle with a predetermined size can be imaged from an object field with a predetermined imaging scale to a predetermined illumination field, wherein the illumination field is completely illuminated in the direction of the first imaging scale, while an increased imaging scale in a second direction does not have negative effect on the throughput of the projection exposure apparatus, but can be compensated for by suitable measures. Therefore, an anamorphic lens enables both the complete illumination of an image area with a large object-side numerical aperture in the first direction, without the extent of the imaging reticle needing to be enlarged in this first direction and without this resulting in a reduction in the throughput of the projection exposure apparatus, and also the minimization of the losses in imaging quality caused by the oblique incidence of the illumination light. As a result of having imaging scales with the same sign in the direction of the two principal sections, an image inversion (“image flip”) is avoided. The optical unit has positive imaging scales, in particular in the direction of the two principal sections. The anamorphic optical unit aids in the generation of an angle of incidence of the imaging light on a reflecting object, which angle of incidence is as small as possible. The larger object-side numerical aperture can be present perpendicular to the incidence plane of the imaging light on the object. The use of a cylindrical optical unit is not mandatory for configuring the anamorphic optical unit. The different imaging scales can have a positive sign for both field coordinates. The different imaging scales can have reducing effect for both field coordinates. The anamorphic projection optical unit can have an elliptical entrance pupil and/or an elliptical exit pupil. The anamorphic projection optical unit can have a rotationally symmetric and an n-fold rotationally symmetric exit pupil. The different imaging scales for the orthogonal field coordinates can differ by at least a factor of 1.1, at least by a factor of 1.2, at least by a factor of 1.3, at least by a factor of 1.4, at least by a factor of 1.5, at least by a factor of 1.7, at least by a factor of 2, at least by a factor of 2.5 and at least by a factor of 3 or else by an even larger factor. The object field can have an xy-aspect ratio of greater than 1, wherein the different imaging scales of the projection optical unit are present in the directions of these two object field dimensions (x, y) of this aspect ratio. A reducing imaging scale (βx) in a longer object field dimension (x) is smaller than in a shorter object field dimension (y) perpendicular thereto. A projection objective can have a direction-dependent object-side numerical aperture. The advantages of such embodiments correspond to what was already discussed above. A smaller imaging scale is tantamount to a smaller reducing effect. The smaller one (βx) of the two different imaging scales can be less than 6. The larger one (βy) of the two imaging scales can be at least 6. Such imaging scales were found to be particularly suitable. By way of example, the smaller one of the two different imaging scales can be 5.4, can be less than 5, can equal 4 or can be even smaller. The larger one of the two different imaging scales can equal 7, can equal 8 or can be even larger. At least one of the mirrors can have a reflection surface in the form of a free-form surface. Such a mirror reflection surface enables an extension to the design degrees of freedom for the projection optical unit. In particular, an anamorphic effect can be distributed on a plurality of mirror surfaces. An image-side numerical aperture can be at least 0.4, such as at least 0.5. An object-side chief ray angle (CRAO) for the field center point of less than 7°, wherein the image field has an extent of more than 13 mm, such as more than 20 mm, along a field dimension (x). Such numerical apertures and image field dimensions are well adapted to desirable properties with respect to the imaging quality and the wafer exposure during use in a projection exposure apparatus. The projection optical unit can have an aperture stop. This aperture stop can lie in a plane or else have a three-dimensional embodiment. The extent of the aperture stop can be smaller in the scanning direction than perpendicular thereto. The projection optical unit can have an obscuration stop. What was explained above in respect of the aperture stop applies in respect of the embodiment of the obscuration stop. A projection optical unit can include a stop with a stop edge, the extent of which along a shorter object field dimension (y) is smaller than along a longer object field dimension (x). Such a stop with an extent ratio is adapted to the anamorphic effect of the projection optical unit. The stop can be arranged in an entrance pupil plane of the projection optical unit. The ratio of the extent along the shorter object field dimension and along the longer object field dimensioned can correspond to the ratio of the reducing imaging scales in the longer object field dimension and in the shorter object field dimension. The features discussed above with reference to the various projection optical units can be realized in any combination with one another. The advantages of an optical system having a stop with a stop edge, the extent of which along a shorter object field dimension (y) is smaller than along a longer object field dimension (x), correspond to those which were already explained above with reference to the projection optical unit. To the extent that use is made of an anamorphic projection optical unit, the illumination optical unit can be adapted to a non-rotationally symmetric entrance pupil of the projection optical unit. The advantages of the projection optical unit are particularly pronounced in an optical system that contains a projection optical unit as disclosed herein. A possible operating wavelength for the EUV light source can be 13.5 nm. Alternatively, use can also be made of a DUV light source, that is to say, for example, a light source with a wavelength of 193 nm. An projection exposure apparatus can include an illumination optical unit for illuminating the object field with illumination and imaging light. The advantages of such a projection exposure apparatus correspond to those which were already explained above with reference to the projection optical unit. An apparatus can have advantages of the anamorphic projection optical unit. A reticle for a projection exposure apparatus described herein can have an extent of at least 104 mm×132 mm. The advantages of a production method and of a microstructured or nanostructured component can correspond to those which were already explained above with reference to the projection optical unit and the optical system and the projection exposure apparatus. The projection exposure apparatus can be used to produce, in particular, a semiconductor component, for example a memory chip. A microlithographic projection exposure apparatus 1 includes a light source 2 for illumination light or imaging light 3. The light source 2 is an EUV light source which generates light in a wavelength range of, for example, between 5 nm and 30 nm, in particular between 5 nm and 15 nm. In particular, the light source 2 can be a light source with a wavelength of 13.5 nm or a light source with a wavelength of 6.9 nm. Other EUV wavelengths are also possible. In general, any desired wavelengths, for example visible wavelengths or else other wavelengths which can find use in microlithography (e.g. DUV, vacuum ultraviolet) and for which suitable laser light sources and/or LED light sources are available (for example 365 nm, 248 nm, 193 nm, 157 nm, 129 nm, 109 nm), are also possible for the illumination light 3 guided in the projection exposure apparatus 1. A beam path of the illumination light 3 is depicted very schematically in FIG. 1. An illumination optical unit 6 serves for guiding the illumination light 3 from the light source 2 to an object field 4 in an object plane 5. Using a projection optical unit or imaging optical unit 7, the object field 4 is imaged in an image field 8 in an image plane 9 with a predetermined reduction scale. In order to simplify the description of the projection exposure apparatus 1 and the various embodiments of the projection optical unit 7, a Cartesian xyz-coordinate system is specified in the drawing, from which the respective positional relations between the components depicted in the figures emerge. In FIG. 1, the x-direction extends perpendicular to the plane of the drawing and into the latter. The y-direction extends to the left and the z-direction extends upward. The object field 4 and the image field 8 are rectangular. Alternatively, it is also possible for the object field 4 and image field 8 to be embodied with a bend or curvature, that is to say, in particular, in the form of a partial ring. The object field 4 and the image field 8 have an xy-aspect ratio of greater than 1. Thus, the object field 4 has a longer object field dimension in the x-direction and a shorter object field dimension in the y-direction. These object field dimensions extend along the field coordinates x and y. One of the exemplary embodiments depicted in FIG. 2ff. can be used for the projection optical unit 7. The projection optical unit 7 according to FIG. 2 has a reduction factor of 8. Other reduction scales are also possible, for example 4×, 5×, or else reduction scales which are greater than 8×. In the embodiments according to FIGS. 2 and 5ff., the image plane 9 in the projection optical unit 7 is arranged parallel to the object plane 5. What is depicted here is a section of a reflection mask 10, which is also referred to as reticle, coinciding with the object field 4. The reticle 10 is carried by a reticle holder 10a. The reticle holder 10a is displaced by a reticle displacement drive 10b. The imaging by the projection optical unit 7 is carried out on the surface of a substrate 11 in the form of a wafer, which is carried by a substrate holder 12. The substrate holder 12 is displaced by a wafer or substrate displacement drive 12a. Between the reticle 10 and the projection optical unit 7, a beam 13 of illumination light 3 entering the latter is schematically depicted in FIG. 1, as is, between the projection optical unit 7 and the substrate 11, a beam 14 of the illumination light 3 emerging from the projection optical unit 7. An image field-side numerical aperture (NA) of the projection optical unit 7 is not reproduced to scale in FIG. 1. The projection exposure apparatus 1 is a scanner-type apparatus. During operation of the projection exposure apparatus 1, both the reticle 10 and the substrate 11 are scanned in the y-direction. A stepper-type projection exposure apparatus 1, in which there is a step-by-step displacement of the reticle 10 and the substrate 11 in the y-direction between individual exposures of the substrate 11, is also possible. These displacements are synchronized to one another by appropriate actuation of the displacement drives 10b and 12a. FIG. 2 shows the optical design of a first embodiment of the projection optical unit 7. Depicted in FIG. 2 is the beam path of in each case three individual rays 15, which emanate from two object field points that are spaced apart from one another in the y-direction in FIG. 2. Chief rays 16, i.e. individual rays 15 which extend through the center of a pupil in a pupil plane of the projection optical unit 7, and in each case an upper and a lower coma ray of these two object field points are depicted. Proceeding from the object field 4, the chief rays 16 include an angle CRAO of 5.5° with a normal of the object plane 5. The object plane 5 lies parallel to the image plane 9. The projection optical unit 7 has an image-side numerical aperture of 0.45. The projection optical unit 7 has a reducing imaging scale of 8×. The projection optical unit 7 according to FIG. 2 has a total of eight mirrors which, in the sequence of the beam path of the individual rays 15 emanating from the object field 4, are numbered M1 to M8 in sequence. An imaging optical unit 7 can also have different number of mirrors, for example four mirrors or six mirrors. FIG. 2 depicts the calculated reflection surfaces of the mirrors M1 to M8. As can be seen from the illustration according to FIG. 2, only a portion of these calculated reflection surfaces is used. Only this actually used region of the reflection surfaces is in fact present in the real mirrors M1 to M8. These used reflection surfaces are carried by mirror bodies in a manner known per se. In the projection optical unit 7 according to FIG. 2, the mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence, that is to say as mirrors on which the imaging light 3 is incident with an angle of incidence that is smaller than 45°. Thus, the projection optical unit 7 according to FIG. 2 has a total of four mirrors M1, M4, M7 and M8 for normal incidence. The mirrors M2, M3, M5 and M6 are mirrors for grazing incidence of the illumination light 3, that is to say mirrors on which the illumination light 3 is incident with angles of incidence which are greater than 60°. A typical angle of incidence of the individual rays 15 of the imaging light 3 on the mirrors M2, M3 and M5, M6 for grazing incidence lies in the region of 80°. Overall, the projection optical unit 7 according to FIG. 2 includes exactly four mirrors M2, M3, M5 and M6 for grazing incidence. The mirrors M2 and M3 form a mirror pair arranged directly behind one another in the beam path of the imaging light 3. The mirrors M5 and M6 also form a mirror pair arranged directly behind one another in the beam path of the imaging light 3. The mirror pairs M2, M3 on the one hand and M5, M6 on the other hand reflect the imaging light 3 in such a way that the angles of reflection of the individual rays 15 on the respective mirrors M2, M3 or M5, M6 of these two mirror pairs add up. Thus, the respective second mirror M3 and M6 of the respective mirror pair M2, M3 and M5, M6 amplifies a deflecting effect exerted by the respectively first mirror M2, M5 on the respective individual ray 15. This arrangement of the mirrors of the mirror pairs M2, M3 and M5, M6 corresponds to the one described in DE 10 2009 045 096 A1 for an illumination optical unit. The mirrors M2, M3, M5 and M6 for grazing incidence in each case have very large absolute values for the radius, i.e. have a relatively small deviation from a plane surface. These mirrors M2, M3, M5 and M6 for grazing incidence therefore have practically no optical power, i.e. practically no overall beam-forming effect like a concave or convex mirror, but contribute to specific and, in particular, to local aberration correction. In order to characterize a deflecting effect of the mirrors of the projection optical unit 7, a deflection direction is defined in the following text on the basis of the respectively depicted meridional sections. As is seen in the respectively incident beam direction in the meridional section, for example according to FIG. 2, a deflecting effect of the respective mirror in the clockwise direction, i.e. a deflection to the right, is denoted by the abbreviation “R”. By way of example, the mirror M1 of the projection optical unit 7 has such an “R” deflecting effect. A deflecting effect of a mirror in the counterclockwise direction, i.e. to the left, as seen from the respective beam direction incident on this mirror, is denoted by the abbreviation “L”. The mirrors M2 and M3 of the projection optical unit 7 are examples for the “L” deflecting effect. A weakly deflecting effect or an entirely non-deflecting effect of a mirror with a fold angle f, for which −1°<f<1° applies, is denoted by the abbreviation “0”. The mirror M7 of the projection optical unit 7 is an example for the “0” deflecting effect. Overall, the projection optical unit 7 for the mirrors M1 to M8 has the following sequence of deflecting effects: RLLLRR0L. In principle, all described exemplary embodiments of the projection optical units can be mirrored about a plane extending parallel to the xz-plane, without basic imaging properties changing in this case. However, of course, this changes the sequence of the deflecting effects, which for example in the case of a projection optical unit emerging from the projection optical unit 7 by the corresponding mirroring has the following sequence: LRRRLL0R. A selection of the deflection effect, i.e. a selection of a direction of the respective incident beam, for example on the mirror M4, and a selection of a deflection direction of the mirror pairs M2, M3 and M5, M6 is selected in such a way in each case that an installation space available for the projection optical unit 7 is used efficiently. The mirrors M1 to M8 carry a coating optimizing the reflectivity of the mirrors M1 to M8 for the imaging light 3. This can be a ruthenium coating, a molybdenum coating or a molybdenum coating with an uppermost layer of ruthenium. In the mirrors M2, M3, M5 and M6 for grazing incidence, use can be made of a coating with e.g. a ply made of molybdenum or ruthenium. These highly reflecting layers, in particular of mirrors M1, M4, M7 and M8 for normal incidence, can be embodied as multi-ply layers, wherein successive layers can be manufactured from different materials. Use can also be made of alternating material layers. A typical multi-ply layer can include 50 bi-plies made of in each case a layer of molybdenum and a layer of silicon. In order to calculate an overall reflectivity of the projection optical unit 7, a system transmission is calculated as follows: a mirror reflectivity is determined on each mirror surface depending on the angle of incidence of a guide ray, i.e. a chief ray of a central object field point, and combined by multiplication to form the system transmission. Here, the reflectivity RM on the mirror in percent emerges as:RM=c0x4+c1x3+c2x2+c3x+c4,where x denotes the respective angle of incidence in degrees. The coefficients ci emerge from:ci=½(ciS-fit+ciP-fit),as mean values of the respective coefficients for S-polarization on the one hand and the P-polarization on the other hand. For an angle of incidence range between 60°<x<88°, the following coefficients emerge for a ruthenium layer, which is therefore impinged upon under grazing incidence angles: c0c1c2c3C4S-Fit01.59347283 × 10−3−4.06503596 × 10−13.56423129 × 101−9.76664971 × 102P-Fit01.88179657 × 10−3−4.79626971 × 10−14.20429269 × 101−1.17059654 × 103 For NI mirrors, i.e. in the region of the perpendicular incidence, the following emerges for a molybdenum/silicon multi-ply stack: c0c1c2c3C4S-Fit2.89135870 × 10−6−3.90173053 × 10−4 1.04448085 × 10−2−2.65742974 × 10−26.66009436 × 101P-Fit2.05886567 × 10−5 5.79240629 × 10−4−3.37849733 × 10−2 3.92206533 × 10−26.65307365 × 101 Further information in respect of a reflection on a GI mirror (mirror for grazing incidence) is found in WO 2012/126867 A. Further information in respect of the reflectivity of NI mirrors (normal incidence mirrors) is found in DE 101 55 711 A. An overall reflectivity or system transmission of the projection optical unit 7, emerging as a product of the reflectivities of all mirrors M1 to M8 of the projection optical unit 7, is R=10.43%. The mirror M8, i.e. the last mirror in the imaging beam path in front of the image field 8, has a passage opening 17 for the imaging light 3, which is reflected from the antepenultimate mirror M6 to the penultimate mirror M7, to pass through. The mirror M8 is used in a reflective manner around the passage opening 17. None of the other mirrors M1 to M7 have passage openings and the mirrors are used in a reflective manner in a continuous region without gaps. The mirrors M1 to M8 are embodied as free-form surfaces which cannot be described by a rotationally symmetric function. Other embodiments of the projection optical unit 7, in which at least one of the mirrors M1 to M8 is embodied as a rotationally symmetric asphere, are also possible. It is also possible for all mirrors M1 to M8 to be embodied as such aspheres. A free-form surface can be described by the following free-form surface equation (Equation 1): Z = c x ⁢ x 2 + c Y ⁢ y 2 1 + 1 - ( 1 + k x ) ⁢ ( c x ⁢ x ) 2 - ( 1 + k y ) ⁢ ( c y ⁢ y ) 2 + C 1 ⁢ x + C 2 ⁢ y + C 3 ⁢ x 2 + C 4 ⁢ xy + C 5 ⁢ y 2 + C 6 ⁢ x 3 + … + C 9 ⁢ y 3 + C 10 ⁢ x 4 + … + C 12 ⁢ x 2 ⁢ y 2 + … + C 14 ⁢ y 4 + C 15 ⁢ x 5 + ⁢ … + C 20 ⁢ y 5 + C 21 ⁢ x 6 + … + C 24 ⁢ x 3 ⁢ y 3 + … + C 27 ⁢ y 6 + … ( 1 ) The following applies to the parameters of this Equation (1): Z is the sag of the free-form surface at the point x, y, where x2+y2=r2. Here, r is the distance from the reference axis of the free-form surface equation (x=0; y=0). In the free-form surface equation (1), C1, C2, C3 . . . denote the coefficients of the free-form surface series expansion in powers of x and y. In the case of a conical base area, cx, cy is a constant corresponding to the vertex curvature of a corresponding asphere. Thus, cx=1/Rx and cy=1/Ry applies. Here, kx and ky each corresponds to a conical constant of a corresponding asphere. Thus, Equation (1) describes a bi-conical free-form surface. An alternative possible free-form surface can be generated from a rotationally symmetric reference surface. Such free-form surfaces for reflection surfaces of the mirrors of projection optical units of microlithographic projection exposure apparatuses are known from US 2007-0058269 A1. Alternatively, free-form surfaces can also be described with the aid of two-dimensional spline surfaces. Examples for this are Bezier curves or non-uniform rational basis splines (NURBS). By way of example, two-dimensional spline surfaces can be described by a grid of points in an xy-plane and associated z-values, or by these points and the gradients associated therewith. Depending on the respective type of the spline surface, the complete surface is obtained by interpolation between the grid points using e.g. polynomials or functions which have specific properties in respect of the continuity and the differentiability thereof. Examples for this are analytical functions. The optical design data of the reflection surfaces of the mirrors M1 to M8 of the projection optical unit 7 can be gathered from the following tables. These optical design data in each case proceed from the image plane 9, i.e. describe the respective projection optical unit in the reverse propagation direction of the imaging light 3 between the image plane 9 and the object plane 5. The first one of these tables provides an overview of the design data of the projection optical unit 7 and summarizes the numerical aperture NA, the calculated design wavelength for the imaging light, the dimensions of the image field in the x- and y-direction, an image field curvature and a location of a stop. This curvature is defined as the inverse radius of curvature of the field. The second one of these tables specifies vertex radii (Radius_x=Rx, Radius_y=Ry) and refractive power values (Power_x, Power_y) for the optical surfaces of the optical components. Negative values for the radius mean concave curves towards the incident illumination light 3 in the section of the respective surface with the observed plane (xz, yz), which is spanned by a surface normal at the vertex with the respective direction of curvature (x, y). The two radii Radius_x, Radius_y can explicitly have different signs. The vertices at each optical surface are defined as points of incidence of a guide ray which extends from an object field center to the image field 8 along a plane of symmetry x=0, i.e. the plane of the drawing of FIG. 2 (meridional plane). The refractive powers Power_x(Px), Power_y(Py) at the vertices are defined as: P x = - 2 ⁢ ⁢ cos ⁢ ⁢ A ⁢ ⁢ O ⁢ ⁢ I R x P y = - 2 R y ⁢ cos ⁢ ⁢ A ⁢ ⁢ O ⁢ ⁢ I Here, AOI denotes an angle of incidence of the guide ray in relation to the surface normal. The third table specifies, for the mirrors M1 to M8 in mm, the conical constants kx and ky, the vertex radius Rx (=Radius_x) and the free-form surface coefficients Cn. Coefficients Cn not found in the table in each case have the value of 0. The fourth table still specifies the magnitude along which the respective mirror, proceeding from a reference surface, was decentered (DCY) in the y-direction, and displaced (DCZ) and tilted (TLA, TLC) in the z-direction. This corresponds to a parallel displacement and a tilt when carrying out the free-form surface design method. Here, a displacement is carried out in the y-direction and in the z-direction in mm, and tilting is carried out about the x-axis and about the z-axis. Here, the tilt angle is specified in degrees. Decentering is carried out first, followed by tilting. The reference surface during decentering is in each case the first surface of the specified optical design data. Decentering in the y-direction and in the z-direction is also specified for the object field 4. In addition to the surfaces assigned to the individual mirrors, the fourth table also lists the image plane as first surface, the object plane as last surface and possibly a stop surface (denoted by “stop”). The fifth table still specifies the transmission data of the mirrors M8 to M1, namely the reflectivity thereof for the angle of incidence of an illumination light ray incident centrally on the respective mirror. The overall transmission is specified as a proportional factor remaining from an incident intensity after reflection at all mirrors in the projection optical unit. The sixth table specifies an edge of the stop (surface M8) as a polygonal chain in local xyz coordinates. This stop is arranged at the location of the mirror M8. The stop is, as is described above, decentered and tilted. TABLE 1 for FIG. 2Exemplary embodimentFIG. 2NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.784mmFeldkruemmung0.01/mmStopM8 TABLE 2 for FIG. 2SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−837.708819270.00236862−757.273649080.00266207REFLM72488.10131627−0.00080383283.66314157−0.00705062REFLM64560.51860808−0.0000726818476.28162004−0.00065317REFLM5−2531.388642140.00014365—0.00010672REFLM4−2528.425980180.00077816−1442.815100270.00140906REFLM3−3050.650468240.0001293334435.31193357−0.00029442REFLM2—0.00000156−40926.794413690.00032129REFLM110833.49940461−0.00017328−2578.140932330.00082650REFL TABLE 3a for FIG. 2CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−837.708819302488.10131600 4560.51860800C7 −9.0132308e−091.11394243e−06 1.59114264e−07C9 −1.00251209e−092.8860992e−07 5.59843391e−09C10−8.87226228e−121.18917173e−093.83909581e−10C12−5.08519375e−115.23800849e−092.11857784e−10C14−1.88200773e−111.0734105e−08 1.39463766e−11C168.82521632e−153.75808998e−121.70877645e−12C18−4.19864966e−151.85595295e−112.66118623e−13C20−2.11360234e−16−1.72133449e−11−5.17043474e−14C21−3.19874264e−173.00011227e−15 9.63300464e−16C23−1.22217908e−164.11542089e−14 4.38089836e−15C25−1.30026191e−161.11642164e−13 1.61278968e−15C27−3.67400697e−173.22598292e−13 1.26838989e−16C291.14026692e−202.92869138e−17 6.77960834e−18C311.0918839e−201.69415114e−16 −5.39777251e−19C33−3.04462195e−214.33073361e−167.8861342e−19C351.02259135e−22−7.37362073e−168.03098684e−19C36−5.63440362e−231.44942891e−20 −3.90732961e−21C38−2.66622412e−223.05621193e−19 5.15318073e−20C40−4.32156525e−221.34609812e−18 −9.54272183e−21C42−2.89279412e−222.45287597e−18 −1.70492308e−20C44−5.99684085e−232.12868884e−18−9.72311004e−22C461.18076072e−26 2.0799062e−22 1.45427907e−22C483.74881822e−262.68414652e−21 4.40689789e−22C501.18386812e−26 5.8670912e−21 2.04987221e−22C52−1.00050188e−26−2.33431824e−20−7.75365541e−24C54−2.93462929e−27−9.59894302e−20−3.00655786e−24C55−7.12926517e−293.05798066e−252.33655571e−25C57−3.54266327e−282.94896726e−247.55277402e−25C59−7.81684172e−282.54027973e−231.26094736e−24C61−8.38095482e−288.05342131e−236.93792966e−25C63−4.13760156e−281.24219439e−229.28250781e−26C65−7.30815611e−294.10221778e−225.47302487e−27C671.94837068e−3200C691.1397448e−3100C711.34382689e−3100C737.55966183e−32 00C75 1.56253375e−32 00C77 6.40963088e−33 00C78 −2.56297737e−3400C80 −1.60836013e−3300C82 −4.69716941e−3300C84 −7.07121378e−3300C86 −5.64664272e−3300C88 −2.27265225e−3300C90 −3.58207435e−3400 TABLE 3b for FIG. 2CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−2531.38864200−2528.42598000 −3050.65046800C71.72781637e−075.8018765e−08−1.17466046e−07C92.14254527e−088.64375408e−099.52322648e−09C101.91545596e−10−1.94203172e−116.38336565e−11C12−1.30545965e−107.93780161e−11−6.09437242e−11C142.29647138e−11−4.96311207e−10−8.46825762e−11C16−2.76920045e−13−4.9519671e−142.46570227e−13C186.31392082e−141.46606283e−121.83720452e−13C205.5820243e−141.34097025e−11−5.79539787e−14C21−7.00730308e−18 8.53806243e−18−1.75797003e−16C233.41967082e−16−9.95579358e−166.08596054e−16C25−7.70078483e−17−1.1212914e−143.41532358e−16C271.30566647e−16−5.35527612e−149.88490631e−17C291.16112452e−192.57671697e−19−1.20254031e−18C31−1.62253585e−19−3.25217486e−186.21318065e−19C33−1.22964972e−19−2.40795277e−161.66737236e−19C351.96436668e−19−4.04068886e−151.33042899e−18C365.2349042e−22−3.5496978e−236.42079101e−22C38−3.65302727e−221.66117198e−21−2.85312334e−21C406.2340516e−233.47327568e−20−6.3375684e−22C429.80519303e−22−1.2946755e−18−2.67858747e−21C44−7.581399e−22−4.6332565e−171.89160718e−21C46−2.8051662e−24−2.53096392e−252.79819801e−24C48−8.01335569e−253.13587836e−24−1.95559965e−24C50−2.19615172e−245.29262773e−22−3.25009825e−24C522.6523186e−248.72077688e−21−1.69895932e−23C54−3.17905172e−24−1.40950195e−19−1.24591949e−23C551.31200881e−286.31299438e−312.44903332e−28C576.46975253e−27−1.44337304e−275.45604256e−27C594.4689247e−27−9.7439448e−262.50408571e−27C61−1.34855282e−27−4.38554687e−25−5.44576542e−27C63−6.32570305e−274.90510476e−23−3.43807004e−26C65−2.36233819e−271.11019478e−22−3.46588884e−26 TABLE 3c for FIG. 2CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−194394.0640000010833.49940000C7−8.67070075e−091.48981967e−09C9−1.03403364e−084.14892815e−09C10−8.56886085e−11 3.38149986e−11C12−2.01940344e−113.90955095e−11C14−7.15883437e−121.45830047e−11C16−9.60210917e−14−6.21111216e−14C18−2.38815926e−149.39500532e−14C20−6.65065222e−161.68138883e−13C21−2.55749187e−161.57821571e−17C23−1.09151386e−16−3.38914384e−17C25−1.97294475e−177.9460803e−18C275.70404899e−181.16530683e−15C291.06431723e−195.16374316e−19C31−1.64115075e−19−1.22836084e−19C33−1.35411374e−20−1.90495661e−18C357.628521e−214.76002684e−18C367.25331258e−221.07417031e−21C38−4.73496575e−224.76896118e−22C40−2.11297656e−22−1.10250035e−21C42−1.02753056e−23−8.66116391e−21C445.07988503e−24−1.22722218e−20C46−9.35932524e−25−6.27142618e−24C48−2.7783366e−25−8.01178971e−24C50−1.59026041e−25−3.05243873e−23C52−6.53452661e−272.93392122e−23C541.824705e−27−8.82506065e−23C552.29320351e−27−6.20705864e−26C574.07644119e−27−1.36210254e−26C59−1.98759397e−28−6.17708439e−26C61−4.48732119e−29−1.10303922e−25C63−1.85722793e−301.36969417e−25C652.81372879e−31−1.05691239e−25 TABLE 4a for FIG. 2SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.00000000724.00020000M70.00000000 −156.2986713395.23660203M60.0000000069.242963011002.51687199M50.00000000376.70486973 1458.55105482M40.00000000768.072021851679.06041506M30.00000000−418.874458281388.75512246M2−0.00000000−951.87794696999.51576030M1−0.00000000−1732.8715030229.24804987Object plane−0.00000000−1870.892654681987.57585464 TABLE 4b for FIG. 2SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M8−7.203607640.00000000−0.00000000M7164.568996790.00000000−0.00000000M666.01183481−0.00000000 180.00000000M546.011834810.000000000.00000000M4−66.466010900.00000000−0.00000000M326.13973836−0.00000000180.00000000M246.139738360.00000000−0.00000000M1164.119643990.000000000.00000000Object plane0.000000000.000000000.00000000 TABLE 5 for FIG. 2SurfaceAngle of incidence [deg]ReflectivityM87.203607640.66017316M70.000006270.66565840M680.460592050.88430204M579.524623320.87198912M410.340023060.65386862M378.622594850.85965098M281.251574200.89438137M120.182602940.61248770Overall transmission0.1043 TABLE 6 for FIG. 2X[mm]Y[mm]Z[mm]0.00000000320.37449215−71.3874328748.36574379316.80745936−71.2747639995.79913948306.15249000−70.94768730141.36313519288.55110075−70.43891500184.11362993264.24936742−69.80243066223.10205565233.61232523−69.11179911257.38560926197.14179980−68.45633706286.04752607155.49451794−67.93434999308.22857191109.49597859−67.64324197323.1687202260.14481518−67.66726101330.255169148.60292360−68.06468586329.07035438−43.83122398−68.85697088319.43251774−95.76530795−70.02235741301.42236387−145.76769643−71.49560404275.39215543−192.42726762−73.17404386241.95716406−234.41168219−74.92871123201.97236169−270.51874890−76.61837302156.49875437−299.71790154−78.10418339106.76380494−321.18109072−79.2631490354.11946362−334.30400997−79.999243410.00000000−338.71937192−80.25155891−54.11946362−334.30400997−79.99924341−106.76380494−321.18109072−79.26314903−156.49875437−299.71790154−78.10418339−201.97236169−270.51874890−76.61837302−241.95716406−234.41168219−74.92871123−275.39215543−192.42726762−73.17404386−301.42236387−145.76769643−71.49560404−319.43251774−95.76530795−70.02235741−329.07035438−43.83122398−68.85697088−330.255169148.60292360−68.06468586−323.1687202260.14481518−67.66726101−308.22857191109.49597859−67.64324197−286.04752607155.49451794−67.93434999−257.38560926197.14179980−68.45633706−223.10205565233.61232523−69.11179911−184.11362993264.24936742−69.80243066−141.36313519288.55110075−70.43891500−95.79913948306.15249000−70.94768730−48.36574379316.80745936−71.27476399 An overall reflectivity of the projection optical unit 7 is 10.43%. The mirrors M1 to M7 are free-form surfaces, in which the free-from surface expansion goes at most to the tenth power of x and y. In the mirror M8, this expansion continues to the twelfth power of x and y. The axes of rotation symmetry of the aspherical mirrors are generally tilted with respect to a normal of the image plane 9, as is made clear by the tilt values in the tables. The mirrors M1, M2, M4, M5 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The mirrors M3, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 have very large absolute radii, i.e. only constitute small deviations from plane reflection surfaces. The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1 mm. The projection optical unit 7 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. A first pupil plane 18 is arranged between the mirrors M2 and M3 in the beam path of the imaging light 3. Unlike what is schematically depicted in FIG. 2, the first pupil plane 18 is tilted relative to the chief ray of a central field point, i.e. it includes an angle of 90° with this chief ray. The whole beam of the imaging light 3 is accessible from all sides in the region of the pupil plane 18 between the mirrors M2 and M3. Therefore, an aperture stop can be arranged in the region of the pupil plane 18. In the following text, this stop is also denoted by the reference sign 18. Alternatively or additionally, it is possible, as explained above in conjunction with Table 6 for FIG. 2, for the stop also to be arranged on the mirror M8. An edge of a stop surface of the stop (cf—also Table 6 for FIG. 2) emerges from intersection points on the stop surface of all rays of the illumination light 3 which, on the image side, propagate at the field center point in the direction of the stop surface with a complete image-side telecentric aperture. When the stop 18 is embodied as an aperture stop, the edge is an inner edge. The stop 18 can lie in a plane or else have a three-dimensional embodiment. The extent of the stop 18 can be smaller in the scanning direction (y) than in the cross-scanning direction (x). An intermediate image 19 of the projection optical unit 7 is arranged in the imaging beam path between the mirrors M3 and M4. A further pupil plane of the projection optical unit 7 is arranged in the region of the reflection of the imaging light 3 on the mirrors M7 and M8. Aperture stops in the region of the mirrors M7 and M8 can be arranged distributed for the x-dimension, on the one hand, and for the y-direction, on the other hand, at two positions in the imaging beam path, for example there can be an aperture stop for primarily providing a restriction along the y-dimension on the mirror M8 and an aperture stop primarily providing a restriction along the x-dimension on the mirror M7. An installation length of the projection optical unit 7 in the z-direction, i.e. a distance between the object plane 5 and the image plane 9, is approximately 2000 mm. The mirror M8 has a diameter lying in the region of 650 mm. A y-distance dOIS between a central object field point and a central image field point is 1870 mm. The projection optical unit 7 has a scanned RMS value of the wavefront aberration which is less than 5 to 10 mλ. The distortion of the projection optical unit 7 is less than 0.12 nm. A telecentricity value of the projection optical unit 7, measured in the x-direction over the image field 8, is less than 6 mrad. A telecentricity value of the projection optical unit 7, measured in the y-direction over the image field 8, is less than 0.4 mrad. The projection optical unit 7 is approximately telecentric on the image side. A working distance between the mirror M7 closest to the image field and the image field 8 is 78 mm. Less than 15% of the numerical aperture is obscured due to the passage opening 17. The obscuration edge is constructed analogously to the way the stop edge is constructed, as explained above in conjunction with the stop 18. When embodied as an obscuration stop, the edge is an outer edge of the stop. In a system pupil of the projection optical unit 7, a surface which cannot be illuminated due to the obscuration is less than 0.152 of the surface of the overall system pupil. The non-illuminated surface within the system pupil can have a different extent in the x-direction than in the y-direction. The non-illuminated surface in the system pupil can be round, elliptical, square or rectangular. Moreover, this surface in the system pupil which cannot be illuminated can be decentered in the x-direction and/or in the y-direction in relation to a center of the system pupil. A further embodiment of a projection optical unit 20, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of the projection optical unit 7, is explained in the following text on the basis of FIG. 3. Components and functions which were already explained above in the context of FIGS. 1 and 2 are appropriately denoted by the same reference signs and are not discussed again in detail. The mirrors M1 to M6 are once again embodied as free-form surface mirrors, for which the free-form surface equation (1) specified above applies. The optical design data of the projection optical unit 20 can be gathered from the following tables, which in terms of their design correspond to the tables in respect of the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 3Exemplary embodimentFIG. 3NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.784mmFeldkruemmung0.01/mmStopM6 TABLE 2 for FIG. 3SurfaceRadius_x[mm]Power_x[1/mm]Radius_y[mm]Power_y[1/mm]OperatingM6−1404.143506010.00142436−1309.122979770.00152774REFLM55382.39322209−0.000371582573.23597524−0.00077723REFLM41869.70984553−0.001050071245.12728595−0.00163626REFLM3−5275.637941560.00036040−2876.867017660.00073127REFLM2—0.00002889117297.48607361−0.00007065REFLM1—0.00000889−59894.008689880.00018903REFL TABLE 3a for FIG. 3CoefficientM6M5M4KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−1404.143506005382.393222001869.70984600C72.03330045e−082.3344482e−077.23054695e−07C94.65863782e−091.18051932e−071.24097017e−06C10−7.84668249e−121.62577951e−101.87744351e−10C12−1.7637487e−115.87834308e−108.29505595e−10C14−6.18838343e−122.5617744e−103.12998874e−09C169.06006234e−152.50004118e−139.06901063e−13C181.02692539e−144.14837589e−131.32517565e−12C204.29131815e−152.84090337e−131.73975885e−11C21−5.55421623e−181.40965954e−165.47388002e−16C23−1.88026398e−179.40416055e−161.58311459e−15C25−1.54749472e−178.25709315e−162.17853503e−14C27−4.79448181e−185.01235176e−168.48825036e−14C294.15266197e−213.91907237e−192.95779995e−18C318.9008726e−211.24932564e−18−9.00584397e−18C338.90593911e−211.73719878e−181.70412678e−16C353.09195946e−219.75392684e−193.3318325e−16C36−3.35220532e−241.95464646e−22−2.10907241e−21C38−1.54416412e−231.95489479e−21−3.54137492e−20C40−2.0112602e−232.59845192e−217.5377104e−20C42−1.26210611e−233.18819744e−211.25792108e−18C44−3.17245779e−241.20046993e−212.21018136e−18C462.57983572e−271.17913803e−24−1.59573436e−23C489.18263006e−276.27728863e−247.54265613e−23C501.41039202e−261.17489615e−233.92042663e−21C526.68942097e−275.23414869e−249.85615328e−21C541.98073687e−28−3.40518909e−241.56979448e−20C55−1.54418379e−302.82069597e−287.73972202e−26C57−7.38488366e−304.3385682e−271.18049046e−24C59−1.24334052e−291.31986693e−267.47854689e−24C61−1.45721166e−292.79892262e−262.8778736e−23C63−8.46049004e−301.43392203e−264.2065804e−23C65−1.46997251e−302.39797376e−275.84041106e−23C671.37077767e−3300C695.96198912e−3300C711.01109499e−3200C736.86378346e−3300C751.49095714e−3300C77−9.91986177e−3400C78−1.55332549e−3600C80−1.18750127e−3500C82−3.4522721e−3500C84−4.95083176e−3500C86−3.9770171e−3500C88−1.77881031e−3500C90−4.7556972e−3600 TABLE 3b for FIG. 3CoefficientM3M2M1KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−5275.63794200−16708.20815000−39723.46084000C78.64742859e−08−8.48534383e−09−2.08763509e−08C93.58476501e−073.56008272e−084.00254821e−09C10−9.89224446e−127.79106894e−12 6.10160158e−12C121.89327581e−10−3.72471221e−112.5509318e−11C14−2.20258778e−118.74900994e−12 −2.0034758e−12C163.36193204e−14−9.31983872e−15−3.37582455e−14C18−2.12152315e−14−1.05001591e−14−2.60298094e−15C201.59066226e−124.18135526e−14 1.5188487e−14C21−3.57227533e−172.48094952e−16−2.46535966e−18C233.58646429e−16−5.00075703e−164.78079643e−16C25−1.15198491e−154.51130937e−17−3.26758719e−17C272.69000089e−15−9.86544399e−171.98569101e−17C292.41625825e−19 9.76505015e−19−7.87248278e−19C31−2.87191946e−18−2.8203702e−19−2.06138283e−19C336.65153055e−185.40607111e−197.02649602e−19C35−5.72207985e−192.31901108e−19−1.87549676e−19C366.83729655e−22−1.00234103e−20−8.03851852e−20C381.73175943e−211.71755837e−211.11388044e−20C40−2.72288684e−20 1.22332554e−20−1.96231837e−20C42−2.97819086e−21−1.20581608e−211.6679562e−22C44−6.38720395e−20−5.106798e−226.16920305e−22C46−5.68914983e−24−5.45078584e−232.3674629e−22C48−2.84889707e−23−6.64895561e−23−3.49242868e−22C503.83000613e−23−4.29346478e−23−1.19854415e−24C52−4.35843617e−22−4.88783101e−24−2.79173067e−24C54−3.75443641e−22 5.45348307e−25−3.58898078e−24C55−1.91069212e−265.17580849e−251.20339e−23C57−1.72210512e−257.20583842e−25−3.2258403e−24C59−1.79738954e−251.20881577e−251.09042629e−24C614.86608652e−255.18691604e−26−1.64197128e−26C63−1.43412851e−24 1.31385226e−26−2.52495238e−26C65−1.41254772e−241.87401871e−289.47040406e−27 TABLE 4a for FIG. 3SurfaceDCXDCYDCZImage plane 0.000000000.000000000.00000000M60.000000000.000000001074.41519438M50.000000000.0000000099.48354955M40.00000000−18.052494151035.70751868M30.00000000354.51020937138.41973030M20.00000000583.207802761031.25041556M10.00000000480.412707021449.24921820Object plane0.00000000285.240031541740.57897606 TABLE 4b for FIG. 3SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M6−0.000000000.00000000−0.00000000M5180.101139840.00000000−0.00000000M410.449145100.00000000−0.00000000M3183.927251610.00000000−0.00000000M2−90.000000000.00000000−0.00000000M1−65.873049310.00000000−0.00000000Object plane219.818065020.00000000−0.00000000 TABLE 5 for FIG. 3SurfaceAOI[deg]ReflectivityM60.000000000.66565840M50.101139840.66566360M410.987977840.65222749M318.069493550.62484145M276.035031850.82099428M179.825516120.87599782Overall transmission0.1299 TABLE 6 for FIG. 3X[mm]Y[mm]Z[mm]0.00000000492.97220996−96.1079492577.13108081486.98647828−95.94002807152.43816471469.15642998−95.45692466224.12261559439.86539988−94.71825918290.44072269399.75735967−93.81572137349.74050124349.74050124−92.86218695400.50664890290.98511318−91.97772489441.41186799224.91058045−91.27386447471.36993312153.15737548−90.83815133489.5836488477.54243221−90.72167600495.580149010.00000000−90.93247362489.22770728−77.48605661−91.43684982470.73236324−152.95021647−92.16852700440.61763177−224.50589688−93.04283923399.69380564−290.39454798−93.97161858349.02334931−349.02334931−94.87488676289.88633185−398.99430615−95.68748150223.74683115−439.12788139−96.36090853152.21937846−468.48307512−96.8619705277.03412861−486.37434617−97.169951490.00000000−492.38475170−97.27376481−77.03412861−486.37434617−97.16995149−152.21937846−468.48307512−96.86197052−223.74683115−439.12788139−96.36090853−289.88633185−398.99430615−95.68748150−349.02334931−349.02334931−94.87488676−399.69380564−290.39454798−93.97161858−440.61763177−224.50589688−93.04283923−470.73236324−152.95021647−92.16852700−489.22770728−77.48605661−91.43684982−495.58014901−0.00000000−90.93247362−489.5836488477.54243221−90.72167600−471.36993312153.15737548−90.83815133−441.41186799224.91058045−91.27386447−400.50664890290.98511318−91.97772489−349.74050124349.74050124−92.86218695−290.44072269399.75735967−93.81572137−224.12261559439.86539988−94.71825918−152.43816471469.15642998−95.45692466−77.13108081486.98647828−95.94002807 An overall reflectivity of the projection optical unit 20 is 12.99%. The projection optical unit 20 has an image-side numerical aperture of 0.45. The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1 mm. The projection optical unit 20 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The projection optical unit 20 has a reducing imaging scale of 8×(β=8). The projection optical unit 20 has exactly six mirrors M1 to M6. The mirrors M1 and M2 are once again embodied as mirrors for grazing incidence and, as a mirror pair, are arranged directly behind one another in the imaging beam path. The projection optical unit 20 has exactly two mirrors for grazing incidence, namely the mirrors M1 and M2. The mirrors M3 to M6 are embodied as mirrors for normal incidence. The projection optical unit 20 has an overall reflectivity which is greater than 11.97%. In absolute terms, the object plane 5 is tilted with respect to the image plane 9 by an angle of approximately 39° about the x-axis. Accordingly, a value TLA of approximately 219° is specified for the object field in the last table above (Table 3b for FIG. 3). A z-distance between the object field 4 and the image field 8 is approximately 1740 mm. The mirror with the largest diameter is the mirror M6 with a diameter value of 1000 mm. A y-distance between the object field 4 and the image field 8, i.e. the value dOIS, is 285 mm at the object field 4. Just as in the projection optical unit 7, an object field-side chief ray angle CRAO is 5.5° in the projection optical unit 20. A scanned RMS value for the wavefront aberration is less than 10.5 mλ in the projection optical unit 20. A distortion value in the projection optical unit 20 is less than 0.1 nm. A telecentricity value of the projection optical unit 20, in the x-direction, is less than 5 mrad on the image field side. A telecentricity value of the projection optical unit 20, in the y-direction, is less than 0.45 mrad on the image field side. In the projection optical unit 20, a pupil plane is arranged in the region of a reflection of the imaging light 3 on the penultimate mirror M5 in the beam path upstream of the image field 8. Therefore, an aperture stop can be arranged on the mirror M5, or else on the mirror M6. The polygonal edge in accordance with preceding Table 6 for FIG. 3 relates to a stop on the mirror M6. The projection optical unit 20 is substantially telecentric on the image side. A working distance between the mirror M5 closest to the image field and the image field 8 is approximately 90 mm. The image field 8 lies in the first image plane of the projection optical unit 20 downstream of the object field 4. Therefore, the projection optical unit 20 does not generate an intermediate image in the imaging beam path between the object field 4 and the image field 8. A pupil obscuration of the projection optical unit 20 is caused by an arrangement of the antepenultimate mirror M4 in the imaging beam path directly in front of a center of the last mirror M6. This obscuration is less than 26% of the image-side numerical aperture of the projection optical unit 20. Only the penultimate mirror M5 in the imaging beam path has a passage opening 17 for the imaging light 3. All other mirrors M1 to M4 and M6 have a continuous reflection surface. The reflection surface of the mirror M5 is used around the passage opening 17 of the latter. The reflection surface of the mirror M6 is not used continuously but only where there is no obscuration by the mirror M4 arranged in front of the reflection surface of the mirror M6. The two mirrors M1 and M2 for grazing incidence deflect the imaging light 3 laterally past the last mirror M6 and around the reflection surface thereof. The mirror M2 is rotated by 90° about the x-axis in relation to the image plane 9, i.e. it is practically perpendicular to the image plane 9. The mirrors M1, M3 and M6 have negative values for the radius, i.e., are, in principle, concave mirrors. The mirrors M2, M4 and M5 have a positive value for the radius, i.e. are, in principle, convex mirrors. The mirrors M1 and M2 for grazing incidence once again have very large radii, i.e. only constitute small deviations from plane reflection surfaces. A further embodiment of a projection optical unit 21, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of the projection optical unit 7, is explained in the following text on the basis of FIG. 4. Components and functions which were already explained above in the context of FIGS. 1 to 3 are appropriately denoted by the same reference signs and are not discussed in detail again. The mirrors M1 to M6 are once again embodied as free-form surfaces, for which the free-form surface equation (1), specified above, applies. The optical design data of the projection optical unit 21 can be gathered from the following tables which, in terms of their design, correspond to the tables in relation to the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 4Exemplary embodimentFIG. 4NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.72mmFeldkruemmung0.01/mmStopM6 TABLE 2 for FIG. 4SurfaceRadius x [mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM6−1833.097106530.00109040−1385.575423020.00144431REFLM518877.49637144−0.00010594277.21693985−0.00721519REFLM41438.66217038−0.001361862430.30119114−0.00084006REFLM3−5662.422167240.00034243−2106.615516670.00097927REFLM2−2969.784619680.000153776812.60965389−0.00128573REFLM1−2412.853202950.00015904—0.00054720REFL TABLE 3a for FIG. 4CoefficientM6M5M4KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−1833.0971070018877.496370001438.66217000C77.14702547e−091.33000904e−072.160143e−07C91.45748065e−09 1.5551429e−061.9750259e−07C10−1.34433863e−123.23052512e−115.21219354e−10C12−8.65246158e−125.51908435e−101.38068278e−09C14−1.26897363e−128.494392e−092.47542622e−09C162.49155269e−157.83281848e−141.30801781e−12C182.81581124e−152.59073558e−122.75791629e−12C202.0590302e−16−3.40842288e−12−8.77664173e−13C21−8.77508671e−191.53250792e−171.64959774e−15C23−5.17996772e−189.13281795e−166.92468226e−15C25−5.66728016e−182.13183138e−141.40378342e−14C27−7.76369168e−191.54890141e−13−1.72019847e−15C297.88863678e−226.55771751e−207.43041791e−18C311.75672504e−213.84581458e−182.35894363e−17C331.18814584e−211.39333507e−169.97718923e−18C351.7493548e−229.81761115e−16−8.01499171e−17C36−3.26021342e−254.67363491e−248.85753541e−21C38−2.46229027e−24 7.7058017e−224.5880821e−20C40−4.93976866e−244.33147562e−209.06865917e−20C42−3.29404362e−241.02682561e−182.64402588e−20C44−2.40295612e−25−5.42295264e−18−1.60806374e−19C462.57227242e−287.65609824e−264.63076076e−23C489.19738739e−289.96764671e−241.91012714e−22C501.09743754e−273.12974539e−221.20398721e−22C526.66432955e−284.91785424e−21−6.82880718e−22C544.73076e−29−1.02818878e−19−1.43891315e−22C55−1.11030431e−311.20361818e−295.11515109e−27C57−8.81991592e−311.86280552e−277.24559338e−26C59−2.38622966e−309.47962857e−266.67407339e−25C61−2.66847543e−301.96385049e−244.01261999e−25C63−1.24137091e−303.77800757e−231.66791629e−24C65−2.2904696e−311.60420604e−221.13771785e−23C677.25951889e−3500C694.78438869e−3400C711.10917899e−3300C731.07566223e−3300C753.02812827e−3400C77−3.25579859e−3500C78−6.82496446e−3800C80−7.3260874e−3700C82−2.69415965e−3600C84−4.80262328e−3600C86−4.4443622e−3600C88 −1.8807898e−3600C90−1.49017219e−3700 TABLE 3b for FIG. 4CoefficientM3M2M1KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−5662.42216700 −2969.78462000−2412.85320300C7−2.05061152e−08−9.01491023e−093.75760309e−08C9−2.38681532e−08−1.07722528e−08−1.82353448e−08C10−4.85387951e−114.11164421e−115.36007066e−11C12−7.98597183e−114.52376364e−116.33402678e−11C14−1.11064223e−105.55561647e−11−2.21093738e−11C163.94476467e−14−6.11601685e−154.38538416e−14C183.00776935e−153.77778718e−145.55251888e−14C20−3.12244022e−148.99013939e−143.83809162e−14C21−3.00816505e−181.02603871e−165.41186271e−17C23−1.21678874e−178.68697433e−17−5.28283589e−17C257.00694254e−17−2.96767637e−171.22856285e−16C271.94317927e−167.96011589e−171.88629304e−16C291.8490636e−205.54481729e−191.47830311e−18C31−4.13981835e−20−1.54413661e−192.63725411e−20C33−7.30655263e−20−5.09614703e−19−1.57531897e−18C35−1.01967973e−192.01225435e−198.95399962e−19C36−1.7395787e−226.68694592e−21−3.03140695e−20C38−4.94707313e−232.32782668e−21−4.39942988e−21C401.78489699e−23−5.19392946e−225.04820517e−21C42−6.0518318e−22−1.28561877e−21−5.75788873e−21C44−6.16746237e−222.31456185e−222.29885486e−21C46−4.02009642e−25−1.74361335e−233.84621986e−23C48−3.28096057e−25−2.28128679e−24−3.25886796e−23C503.55844765e−27−1.29996778e−242.31874654e−23C522.77737882e−25−3.09482301e−24−3.60029308e−24C547.20889308e−26−3.20584144e−251.90845046e−24C552.93653556e−27−2.73182908e−252.44630793e−24C573.4262361e−27−1.1889464e−255.67957006e−25C591.45309977e−28−8.784571e−27−1.36102401e−25C616.41931285e−28−3.29041198e−273.37050556e−26C639.79557956e−28−3.38378135e−278.90781735e−27C657.94905548e−28−6.28588637e−28−9.66111645e−28 TABLE 4a for FIG. 4SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M60.000000000.000000001336.04673264M50.0000000088.9826274649.91664546M40.0000000034.160512061290.78810464M30.00000000536.44795589234.08633307M20.00000000−715.744343741150.16573744M10.00000000−995.947993671693.10641178Object plane0.00000000−1039.516782602186.05270414 TABLE 4bfor FIG. 4SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M61.984766640.00000000−0.00000000M5183.272178300.00000000−0.00000000M414.010243170.00000000−0.00000000M3219.658115140.00000000−0.00000000M2130.801427430.00000000−0.00000000M1106.497258960.00000000−0.00000000Object plane−0.000000000.00000000−0.00000000 TABLE 5 for FIG. 4SurfaceAngle of incidence [deg]ReflectivityM61.984766640.66533020M50.752008470.66564033M411.584675140.65060513M314.190640830.64216831M276.801064200.83300871M178.937937360.86402184Overall transmission0.1332 TABLE 6 for FIG. 4X[mm]Y[mm]Z[mm]0.00000000608.52234041−140.6468357595.94023321601.25931900−139.86882799189.75379987579.58413919−137.60310659279.30462104543.84975389−134.05121860362.44987510494.67987297−129.53696039437.06577774433.01415623−124.48536770501.10457736360.15495964−119.38904049552.68495125277.79910686−114.76081019590.20868666188.03626648−111.07562152612.4855734093.29913092−108.70965207618.84016352−3.73883968−107.88877482609.17368855−100.30707275−108.65869405583.96436539−193.69806970−110.88422162544.20637659−281.41366860−114.27689980491.30439984−361.27238788−118.44241764426.94956472−431.46613730−122.93554700353.00187334−490.56898267−127.31151102271.39634739−537.51059935−131.16696091184.08035860−571.53072807−134.1684349292.98146093−592.12968050−136.069582670.00000000−599.02618416−136.72010822−92.98146093−592.12968050−136.06958267−184.08035860−571.53072807−134.16843492−271.39634739−537.51059935−131.16696091−353.00187334−490.56898267−127.31151102−426.94956472−431.46613730−122.93554700−491.30439984−361.27238788−118.44241764−544.20637659−281.41366860−114.27689980−583.96436539−193.69806970−110.88422162−609.17368855−100.30707275−108.65869405−618.84016352−3.73883968−107.88877482−612.4855734093.29913092−108.70965207−590.20868666188.03626648−111.07562152−552.68495125277.79910686−114.76081019−501.10457736360.15495964−119.38904049−437.06577774433.01415623−124.48536770−362.44987510494.67987297−129.53696039−279.30462104543.84975389−134.05121860−189.75379987579.58413919−137.60310659−95.94023321601.25931900−139.86882799 An overall reflectivity of the projection optical unit 21 is 13.32%. The projection optical unit 21 has a reducing imaging scale of 8×(β=8). The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 0.8 mm. The projection optical unit 21 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. Like the projection optical unit 20, the projection optical unit 21 is also a purely catoptric projection optical unit with exactly six mirrors M1 to M6. Like in the projection optical unit 20, the first two mirrors M1 and M2 of the projection optical unit 21 in the imaging beam path downstream of the object field 4 are embodied as mirrors for grazing incidence. The further mirrors M3 to M6 are embodied as mirrors for normal incidence. Unlike the beam guidance of the projection optical units 7 and 20, the chief rays cross in the beam guidance of the projection optical unit 21. This crossing occurs between the partial imaging beam paths between the mirrors M2 and M3 on the one hand and between M4 and M5 on the other hand, where a crossing region K1 is indicated. A further crossing of the chief rays of the imaging partial beam between the mirrors M2 and M3 occurs with the chief rays of the imaging partial beams on the one hand between the mirrors M5 and M6 and between the mirror M6 and the image field on the other hand, which is indicated by further crossing regions K2 and K3. In the projection optical unit 21, the object plane 5 and the image plane 9 extend parallel to one another. The mirrors M1, M3 and M6 have negative values for the radius, i.e. are, in principle, concave mirrors. The mirrors M2, M4 and M5 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M1 and M2 once again have very large absolute radii, i.e. only constitute small deviations from plane reflection surfaces. Like in the projection optical unit 20, the antepenultimate mirror M4 of the projection optical unit 21 is arranged in front of a center of a reflection surface of the last mirror M6 and therefore causes a pupil obscuration of the projection optical unit 21. In the projection optical unit 21, none of the mirrors M1 to M6 have a passage opening for the imaging light 3. Except for in the case of the mirror M6, all reflection surfaces of the projection optical unit 21, i.e. the reflection surfaces of the mirrors M1 to M5, can be used without gaps. The reflection surface of the mirror M6 is used were no obscuration due to the mirror M4 occurs. In the projection optical unit 21, a z-distance between the object plane 5 and the image plane 9 is approximately 2200 mm. A typical diameter of the largest mirror M6 is approximately 1200 mm. An object/image offset dOIS is approximately 1100 mm in the projection optical unit 21. In the projection optical unit 21, the object field-side chief rays 16 also include an angle CRAO of 5.5° with a normal of the object plane 5. The projection optical unit 21 has a scanned RMS value of the image field-side wavefront which is less than 11 mλ. In the projection optical unit 21, an image field-side distortion value is less than 0.1 nm. In the projection optical unit 21, an image-side telecentricity value in the x-direction is less than 4 mrad. In the projection optical unit 21, an image-side telecentricity value in the y-direction is less than 0.3 mrad. In the projection optical unit 21, a pupil plane is arranged in the region of a reflection of the imaging light 3 on the mirror M6. Therefore, an aperture stop can be provided on the mirror M6. The polygonal edge in accordance with preceding Table 6 for FIG. 4 relates to this stop position on the mirror M6. Like the projection optical unit 20, the projection optical unit 21 does not have an intermediate image either. The projection optical unit 21 is substantially telecentric on the image side. A working distance between the mirror closest to the image field, the penultimate mirror M5 in the imaging beam path, and the image field 8 is 36 mm. The mirror M4 defines an image-side obscuration, which is less than 23% of the image-side numerical aperture of the projection optical unit 21. A further embodiment of a projection optical unit 22, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 5. Components and functions which were already explained above in the context of FIGS. 1 to 4 are appropriately denoted by the same reference signs and are not discussed again in detail. Overall, the projection optical unit 22 has seven mirrors M1 to M7. The projection optical unit 22 has three mirrors for grazing incidence, namely the mirrors M1 to M3, and four mirrors for normal incidence, namely the mirrors M4 to M7. These mirrors M1 to M7 are once again configured as free-form surfaces, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 22 can be gathered from the following tables, which, in terms of their design, correspond to the tables in relation to the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 5Exemplary embodimentFIG. 5NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.98mmFeldkruemmung0.01/mmStopM7 TABLE 2 for FIG. 5SurfaceRadius_x[mm]Power_x[1/mm]Radius_y[mm]Power_y[1/mm]OperatingM7—0.00117460—0.00125545REFLM67360.39271982−0.000271723417.65341930−0.00058520REFLM52115.61242515−0.000927381567.72388388−0.00130046REFLM4—0.00031874—0.00057981REFLM30.00000000−inf0.00000000−infREFLM20.00000000−inf0.00000000−infREFLM10.00000000 inf0.00000000 infREFL TABLE 3a for FIG. 5CoefficientM7M6M5KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−1702.700243007360.39272000 2115.61242500C71.79847891e−081.92019811e−076.09839447e−07C93.08103036e−097.1188267e−087.08555971e−07C10−4.24845893e−128.96360067e−11 1.42628939e−10C12−9.53203499e−123.27897349e−10 6.15654836e−10C14−3.56696766e−121.32008619e−10 1.24698071e−09C165.53144807e−151.36194158e−136.05714405e−13C186.34539803e−152.34455978e−131.21593408e−12C201.81140787e−159.69419966e−145.15369198e−12C21−2.11810311e−185.15348174e−172.91434391e−16C23−7.16043548e−183.75752681e−161.25156571e−15C25−5.88402712e−183.19181834e−168.70563351e−15C27−1.92557933e−181.53807396e−161.63908034e−14C291.70059672e−211.40780709e−191.39069823e−18C313.75540269e−214.85996976e−19−1.28410259e−18C333.28133541e−215.1910323e−194.8095941e−17C358.57809825e−222.15178451e−19 4.41927219e−17C36−8.85938941e−254.80137725e−23−6.58463052e−22C38−4.20002708e−245.52918171e−22 −1.31151539e−20C40−5.24288951e−247.37589979e−223.29070838e−20C42−3.32443155e−247.62607475e−222.45737341e−19C44−8.41638073e−252.11429097e−221.98567595e−19C467.40583899e−282.94044566e−25−2.1351782e−24C482.7860108e−271.65594542e−24 5.42339274e−23C504.05802066e−27 2.67363596e−249.40249237e−22C521.8873941e−271.45438443e−24 1.40511532e−21C541.32906947e−28−1.74731802e−258.67008547e−22C55−2.72625411e−314.57055919e−291.975511e−26C57−1.09517773e−308.24315234e−28 3.5245026e−25C59−1.54140059e−302.7846066e−27 1.86064293e−24C61−2.03920564e−305.04844296e−27 5.56594105e−24C63−1.39151659e−302.65275439e−274.93123257e−24C65−3.04302425e−314.47315051e−28 2.25513424e−24C672.65932555e−3400C691.07192285e−3300C711.59913365e−3300C739.28830744e−3400C752.99613864e−3400C77−2.87821803e−3500C78−1.91467081e−3700C80−1.59911782e−3600C82−4.94780249e−3600C84−7.14686431e−3600C86−5.51076275e−3600C88−2.16822816e−3600C90−4.19310084e−3700 TABLE 3b for FIG. 5CoefficientM4M3M2KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−5959.738359000.000000000.00000000C77.09371063e−0800C91.9620957e−0700C10−5.80501996e−1200C121.02443869e−1000C14−1.92463151e−1100C161.52210927e−1400C181.53632928e−1400C205.26048968e−1300C21−1.12436683e−1700C231.73824765e−1600C25−2.15389944e−1600C276.93749405e−1600C297.32299538e−2000C31−8.96220063e−1900C332.89314095e−1800C353.66266246e−1900C361.37832263e−2200C384.81965046e−2200C40−7.84784597e−2100C42−4.14050678e−2200C44−6.21735194e−2100C46−8.56329267e−2500C48−5.86480301e−2400C507.86836679e−2400C52−7.38234303e−2300C54−1.90896327e−2300C55−3.44134447e−2700C57−4.07630281e−2600C59−2.05268913e−2600C617.40916254e−2600C63−1.66787506e−2500C65−9.99341642e−2600 TABLE 3c for FIG. 5CoefficientM1KY0.00000000KX0.00000000RX0.00000000 TABLE 4a for FIG. 5SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M70.000000000.000000001294.60000000M60.000000000.00000000121.16860083M50.00000000−23.396450801255.70266623M40.00000000428.84722309176.16839633M30.00000000643.29322055973.30911463M20.00000000877.394049101272.63636377M1−0.00000000985.696986771709.40915790Object plane−0.00000000972.970835372079.13057086 TABLE 4b for FIG. 5SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M7−0.000000000.00000000−0.00000000M6180.076480950.00000000−0.00000000M510.529604780.00000000−0.00000000M4184.022559450.00000000−0.00000000M364.022559450.00000000180.00000000M2244.02255945−0.000000000.00000000M184.02255945−0.00000000 180.00000000Object plane−11.954881110.00000000180.00000000 TABLE 5 for FIG. 5SurfaceAOI[deg]ReflectivityM70.000000000.66565840M60.076480950.66566255M511.189559820.65169152M418.229178900.62398638M377.948835710.85008675M277.948835710.85008675M197.948835711.13089334Overall transmission0.1473 TABLE 6 for FIG. 5X[mm]Y[mm]Z[mm]0.00000000594.49311802−114.8237108293.01621208587.28124992−114.60806119183.83820338565.79581204−113.99060454270.29866175530.49099318−113.05582694350.29086890482.13401886−111.93168041421.81384811421.81384811−110.77184822483.02993602350.94179082−109.73400756532.33125383271.23632139−108.95707827568.40749899184.68679191−108.54096691590.3050883893.49514104−108.53242876597.467924070.00000000−108.92018472589.75339789−93.40776185−109.64091015567.42315516−184.36695921−110.59493328531.11439345−270.61630005−111.66734917481.80099693−350.04891430−112.74857877420.75295187−420.75295187−113.74927261349.49841703−481.04330244−114.60719325269.78833350−529.48941760−115.28660147183.56074169−564.94187277−115.7724641892.90157512−586.55746064−116.062331210.00000000−593.82052455−116.15847788−92.90157512−586.55746064−116.06233121−183.56074169−564.94187277−115.77246418−269.78833350−529.48941760−115.28660147−349.49841703−481.04330244−114.60719325−420.75295187−420.75295187−113.74927261−481.80099693−350.04891430−112.74857877−531.11439345−270.61630005−111.66734917−567.42315516−184.36695921−110.59493328−589.75339789−93.40776185−109.64091015−597.46792407−0.00000000−108.92018472−590.3050883893.49514104−108.53242876−568.40749899184.68679191−108.54096691−532.33125383271.23632139−108.95707827−483.02993602350.94179082−109.73400756−421.81384811421.81384811−110.77184822−350.29086890482.13401886−111.93168041−270.29866175530.49099318−113.05582694−183.83820338565.79581204−113.99060454−93.01621208587.28124992−114.60806119 An overall reflectivity of the projection optical unit 22 is 11.89%. The projection optical unit 22 has a reducing imaging scale of 8×(β=8). The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1 mm. The projection optical unit 22 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. In the region of, on the one hand, the mirrors M1 and M2 and, on the other hand, the mirrors M4 to M7, the beam path of the projection optical unit 22 corresponds qualitatively to that from the projection optical unit 20 according to FIG. 3. In contrast to the projection optical unit 20, a further mirror M3 for grazing incidence is arranged between the mirror M2 for grazing incidence and the mirror M4 for normal incidence in the projection optical unit 22. Compared to the deflecting effect of the mirrors M1 and M2 for grazing incidence, this further mirror causes a reverse deflection of the imaging light 3 toward the mirror M4 in such a way that, unlike in the case of the projection optical unit 20, the object plane 5 in the projection optical unit 22 is not arranged with such a strong tilt with respect to the image plane 9. Alternatively, the projection optical unit 22 can also be embodied in such a way that the object plane 5 is arranged parallel to the image plane 9. The mirrors M1 and M2 once again form a pair of mirrors for grazing incidence, arranged directly behind one another in the beam path of the imaging light 3. A further difference in the guidance of the imaging light 3 in the projection optical unit 22 compared to in the projection optical unit 20 lies in the fact that the mirror M7 includes a passage opening 17 for the imaging light 3 between the mirrors M4 and M5 on the one hand and the mirrors M5 and M6 on the other hand. A reflection surface of the mirror M5 is arranged recessed relative to this passage opening 17 in the mirror M7. The mirrors M1, M3, M4 and M7 have negative values for the radius, i.e. are, in principle, concave mirrors. The mirrors M2, M5 and M6 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M6 and M7 respectively have a passage opening 17 for the imaging light 3. The other mirrors M1 to M5 do not have passage openings for the imaging light 3. The reflection surfaces of the mirrors M6 and M7 are used around the respective passage opening 17 thereof. In the projection optical unit 22, an aperture stop is arranged on the mirror M7. The polygon data in accordance with preceding Table 6 for FIG. 5 relate thereto. In the projection optical unit 22, a z-distance between the object plane and the image plane 9 is approximately 2200 mm. A typical diameter of the largest mirror M7 is approximately 1350 mm. In the projection optical unit 22, an object/image offset dOIS is approximately 1050 mm. In the projection optical unit 22, the object field-side chief rays 16 also include an angle CRAO of 5.5° with a normal of the object plane 5. The projection optical unit 22 has a scanned RMS value of the image field-side wavefront which is approximately 100 mλ. An image field-side distortion value is approximately 2 nm in the projection optical unit 22. In the projection optical unit 22, an image-side telecentricity value in the x-direction is less than 2 mrad. In the projection optical unit 22, an image-side telecentricity value in the y-direction is less than 0.5 mrad. In the projection optical unit 22, the chief rays 16 propagate divergently with respect to one another between the object field 4 and the mirror M1. The mirror M6 defines an image-side obscuration in the x-dimension which is less than 26% of the image-side numerical aperture of the projection optical unit 22. In the y-direction, the obscuration is significantly smaller and moreover decentered. A further embodiment of a projection optical unit 23, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 6. Components and functions which were already explained above in the context of FIGS. 1 to 5 are appropriately denoted by the same reference signs and are not discussed again in detail. Overall, the projection optical unit 23 has eight mirrors M1 to M8. Of these, the mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence and the mirrors M2, M3 as well as M5 and M6 are embodied as mirrors for grazing incidence. The mirrors M1 to M8 are configured as free-form surfaces, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 23 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. The specification “stop S8” in Table 1 for FIG. 6 means that the stop is arranged at the location of the eighth surface of the design surfaces, counted including the image plane (cf. in this respect Tables 4a, 4b for FIG. 6). Corresponding specifications concerning the location of the stop can also be found in the described embodiments of the projection optical unit still to follow. TABLE 1 for FIG. 6Exemplary embodimentFIG. 6NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.784mmFeldkruemmung0.01/mmStopS8 TABLE 2 for FIG. 6SurfaceRadius_x[mm]Power_x[1/mm]Radius_y[mm]Power_y[1/mm]OperatingM8−958.970895750.00207686−961.856467600.00208803REFLM7781.70184576−0.00255743800.14521302−0.00250061REFLM62530.53650030−0.000172481099.72037229−0.00833342REFLM5−959.517076160.00053343−5824.087767930.00134184REFLM4−1015.899479770.00190347−1037.476389760.00199381REFLM3−1396.794199840.000250795530.47714724−0.00206466REFLM2453.37653174−0.001345513069.00502651−0.00213656REFLM1−1105.895469660.00175044−898.049245150.00230091REFL TABLE 3a for FIG.6CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−958.97089570781.701845802530.53650000C7−6.24261885e−09−4.79337518e−07−7.1009777e−07C93.40176704e−09−2.2271152e−08−8.2763755e−07C10−9.52920854e−121.39847445e−09−5.28790727e−09C12−2.17138503e−112.59902235e−09−5.83047016e−09C14−5.53794085e−123.82503297e−103.85928616e−09C16−4.89194598e−15−7.5682079e−134.16412253e−11C18−5.31097983e−152.0123627e−133.27030642e−11C203.35556271e−151.18707056e−12−1.69195332e−11C21−1.29683082e−176.50353918e−15−1.04672087e−14C23−4.0507372e−171.51137687e−14−2.41277384e−14C25−3.91228171e−171.36743637e−14−2.38109022e−13C27−8.22368178e−182.04416547e−159.07489874e−14C29−4.09694624e−21−2.41814134e−184.54711839e−16C31−8.94104942e−21−2.23789497e−19−8.11985983e−16C33−2.65451858e−211.31365906e−171.31994251e−15C353.82604616e−211.24161702e−17−6.01734444e−16C36−1.25909252e−235.60405318e−20−1.9034482e−18C38−5.04636427e−231.727638e−19−1.29641861e−17C40−7.58006457e−23 2.38455591e−196.23929199e−18C42−4.61626479e−23 9.83846873e−20−1.3014572e−17C44−8.32692765e−24 3.34129348e−205.06711727e−18C46−8.53689744e−2700C48−2.77252948e−2600C50−2.88379308e−2600C52−3.62035322e−2700C546.3984309e−2700C55−2.76049035e−2900C57−1.41544439e−2800C59−2.85021143e−2800C61−2.76943917e−2800C63−1.24085088e−2800C65−1.81757986e−2900 TABLE 3b for FIG. 6CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−959.51707620−1015.89948000 −1396.79420000C7−4.08359998e−07−2.15395805e−07−2.38764091e−07C93.4748349e−081.36820595e−074.64016378e−08C10−9.13196608e−10−4.36123019e−11−4.14715679e−09C129.44559924e−111.25327362e−09−9.81520016e−10C14−5.88672435e−11−1.25208732e−102.37258013e−11C16−1.87521812e−12−2.06101634e−129.14454531e−12C18−1.37465885e−12−6.89740416e−122.95923304e−12C201.1992969e−131.04902531e−123.68847523e−13C21−4.39551393e−14−5.27163213e−17−2.48685307e−13C23−6.94239353e−152.41662997e−14−1.22998777e−13C251.42589153e−154.92614883e−14−1.38722747e−14C274.24263352e−17−2.58241283e−141.75833705e−17C291.63548588e−16−3.62334861e−171.422768e−15C319.81035253e−17−3.34821808e−165.43158823e−16C33−7.95045663e−18−1.33308143e−166.79918691e−17C35−5.12592669e−19−4.92438934e−166.81835572e−19C366.9842749e−192.51610148e−215.8931813e−18C38−1.66279358e−19 7.3298455e−19 −6.55610075e−18C40−6.28447234e−19 1.69443664e−18 −1.55271887e−18C422.04767376e−20−3.36811757e−19−1.30349519e−19C442.18932434e−21−1.74132521e−171.24548926e−20 TABLE 3c for FIG. 6CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX453.37653170−1105.89547000C7−3.64021023e−06−1.53061966e−08C9−4.1440416e−072.02696728e−07C101.73428138e−10 5.3320966e−11C121.50361672e−08 3.69218174e−10C148.05092825e−11−4.33240146e−11C163.86788386e−116.58986798e−14C18−6.30736684e−11−9.56533957e−13C203.23174009e−121.76624492e−15C211.06689208e−13−2.93652599e−17C23−9.8827162e−14−1.44343666e−15C252.53626119e−134.60503135e−15C27−6.71346795e−17 3.22197521e−15C29−3.85691883e−16 7.4131948e−19C31−8.34354289e−17 1.97074044e−17C33−1.00493209e−15−4.84993134e−19C35−9.32551743e−181.5674206e−18C363.32160664e−18−2.75117422e−22C382.42658882e−181.69392814e−21C408.35990203e−19−9.62768209e−20C422.82957021e−18−4.99071337e−20C44−2.18809094e−19−2.52307032e−19 TABLE 4a for FIG. 6SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.00000000857.25842051M70.00000000143.7284627878.92107486M60.00000000−97.732604181061.22710854M50.00000000−310.853390131324.12983099M40.00000000−415.104587601955.31068719M30.00000000−109.21713535 1576.99752720Stop0.0000000053.837670371451.75625757M20.00000000233.834615051371.94162077M10.00000000434.90609681911.92780520Object plane0.00000000 524.230073791839.29231153 TABLE 4b for FIG. 6SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M85.237732030.00000000−0.00000000M7192.161525970.00000000−0.00000000M6−63.566515490.00000000−0.00000000M5114.204899640.00000000−0.00000000M424.167266660.00000000−0.00000000M3139.044158200.00000000−0.00000000Stop238.000000000.00000000−0.00000000M2−48.627796040.00000000−0.00000000M1189.054637770.00000000−0.00000000Object plane−0.000000000.00000000−0.00000000 TABLE 5 for FIG. 6SurfaceAngle of incidenceReflectivityM85.237732030.66285728M71.673163190.66544123M677.394605900.84197074M575.171942290.80679858M414.789886440.63989082M379.912399480.87714614M272.241139950.75250143M114.556576860.64079353Overall transmission0.0811 TABLE 6 for FIG. 6X[mm]Y[mm]Z[mm]0.00000000−42.555506300.00000000−5.71360072−42.419040790.00000000−11.28570917−42.003373270.00000000−16.57923089−41.291992970.00000000−21.46534853−40.264328530.00000000−25.82651690−38.904193690.00000000−29.55850056−37.208561370.00000000−32.57173218−35.194563810.00000000−34.79247198−32.903061610.00000000−36.16417382−30.398035090.00000000−36.64920435−27.761945400.00000000−36.23077173−25.088059980.00000000−34.91468027−22.471406430.00000000−32.73039949−20.000224950.00000000−29.73098648−17.749530500.00000000−25.99165105−15.777785450.00000000−21.60711600−14.126777720.00000000−16.68821822−12.823866520.00000000−11.35826608−11.885319940.00000000−5.74952640−11.319715440.00000000−0.00000000−11.130841570.000000005.74952640−11.319715440.0000000011.35826608−11.885319940.0000000016.68821822−12.823866520.0000000021.60711600−14.126777720.0000000025.99165105−15.777785450.0000000029.73098648−17.749530500.0000000032.73039949−20.000224950.0000000034.91468027−22.471406430.0000000036.23077173−25.088059980.0000000036.64920435−27.761945400.0000000036.16417382−30.398035090.0000000034.79247198−32.903061610.0000000032.57173218−35.194563810.0000000029.55850056−37.208561370.0000000025.82651690−38.904193690.0000000021.46534853−40.264328530.0000000016.57923089−41.291992970.0000000011.28570917−42.003373270.000000005.71360072−42.419040790.00000000 An overall reflectivity of the projection optical unit 23 is 8.11%. The projection optical unit 23 has a reducing imaging scale of 8×(β=8). The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1 mm. The projection optical unit 23 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. Deviating from the other projection optical units, the projection optical unit 23 has an image-side numerical aperture of 0.45. A beam path of the imaging light 3 through the projection optical unit 23 between the mirror M6 and the image field 8 corresponds qualitatively to the beam path between the mirror M6 and the image field 8 in the projection optical unit 7 according to FIG. 2, albeit mirrored about a plane parallel to the xz-plane. The mirrors M2 and M3, on the one hand, and the mirrors M5 and M6, on the other hand, for grazing incidence are arranged in such a way that they have a respective reverse deflecting effect, that is to say that the deflecting effect of the respective second mirror M3 and M6 of these mirror pairs M2, M3 and M5, M6 is subtracted from the deflecting effect of the respective first mirror M2 and M5. In respect of in each case one of the mirrors M2 and M3, the mirrors M5 and M6 have a reverse dependence on the reflectivity for respective individual rays 15 of the imaging light 3, i.e. these represent compensation mirrors such that the four mirrors M2, M3, M5 and M6 for grazing incidence do not have an undesired overall dependence on the reflectivity over the image field 8 or over the illumination angle distribution thereof. A pupil plane of the projection optical unit 23 lies in the region of the deflection on the mirror M2. An aperture stop effective for the x-dimension can be arranged in the beam path of the imaging light 3 between the mirrors M1 and M2, adjacent to M2. An aperture stop acting in the y-dimension can be arranged in the beam path of the imaging light 3 between the mirrors M2 and M3, once again adjacent to the mirror M2. An intermediate image plane of the projection optical unit 23 lies in the region of the deflection on the mirror M5. A further pupil plane lies in the beam path of the imaging light 3 between the mirrors M7 and M8. There, an aperture stop effective for the x-dimension can likewise be arranged. In sections, the mirrors M1 and M8 are embodied back-to-back. Only the mirror M8 has a passage opening 17 for the passage of imaging light 3 in the imaging beam path between the mirrors M6 and M7. The mirrors M1, M4, M5 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The mirrors M2, M3, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3 and M5 have very large absolute radii, i.e. only constitute small deviations from plane reflection surfaces. A z-distance between the object plane 5 and the image plane 9 is approximately 1840 mm in the projection optical unit 23. A typical diameter of the largest mirror M8 is approximately 800 mm. In the projection optical unit 23, an object/image offset dOIS is approximately 520 mm. In the projection optical unit 23, the object field-side chief rays 16 also include an angle CRAO of 5.5° with a normal of the object plane 5. The projection optical unit 23 has a scanned RMS value of the image field-side wavefront which is less than 70 mλ. An image field-side distortion value is approximately 1.2 nm in the projection optical unit 23. In the projection optical unit 23, the chief rays 16 propagate divergently with respect to one another between the object field 4 and the mirror M1. The mirror M8 defines an image-side obscuration in the x-dimension which is less than 20% of the image-side numerical aperture of the projection optical unit 23. In the y-direction, the obscuration is significantly smaller and moreover decentered. A further embodiment of a projection optical unit 24, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 7. Components and functions which were already explained above in the context of FIGS. 1 to 6 are appropriately denoted by the same reference signs and are not discussed again in detail. The imaging beam path of the projection optical unit 24 corresponds qualitatively to that of the projection optical unit 23 according to FIG. 6. The projection optical unit 24 also includes eight mirrors M1 to M8, of which the mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence and the mirrors M2, M3, M5 and M6 are embodied as mirrors for grazing incidence. The deflecting effects of the mirrors M2 and M3 on the one hand, and M5 and M6 on the other hand are subtracted from one another. The mirrors M1 to M8 are configured as free-form surfaces, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 24 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 7Exemplary embodimentFIG. 7NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.784mmField curvature0.01/mmStopS7 TABLE 2 for FIG. 7SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−828.906246580.00240718−813.731842150.00246356REFLM7452.59444650−0.00441888343.07524055−0.00582974REFLM61112.77153576−0.00035436−8434.603439470.00120266REFLM5−743.460913180.0005335610280.07421667−0.00098089REFLM4−835.779755240.00235223−929.016940990.00219010REFLM3—0.00007233−4677.483758230.00212963REFLM2—0.000231221872.02689047−0.00534493REFLM1−880.944746130.00217245−929.968277440.00224746REFL TABLE 3a for FIG. 7CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−828.90624660452.594446501112.77153600C76.74198948e−091.8198381e−074.73297971e−07C93.90647354e−09−1.03077896e−075.71100371e−08C10−1.60344671e−115.15323975e−092.05867386e−09C12−2.86549213e−11 1.1999558e−08−8.29784809e−10C14−1.26862354e−117.63575592e−09−9.58970523e−11C164.78369091e−151.39254302e−12−2.17825923e−11C188.51266815e−157.38520647e−12 6.3635415e−13C202.82358426e−15−2.36224044e−121.31296379e−13C21−2.65461735e−176.84835025e−14−1.01503317e−13C23−7.72188599e−172.86517775e−134.04729312e−14C25−7.21196735e−173.43322922e−135.59417154e−16C27−1.90211316e−177.51227642e−14−1.51792851e−16C294.92227907e−214.09353362e−172.54136872e−16C311.20218531e−201.27335094e−16−5.10416424e−17C338.40798497e−211.22660287e−16−2.15218211e−18C353.23694092e−21−4.21844295e−171.02982467e−19C36−3.28705775e−231.68544205e−18−2.64826102e−19C38−1.3081706e−229.48378409e−18−4.72935253e−19C40−1.91271179e−221.93084784e−171.36626279e−20C42−1.20985451e−221.51684275e−171.50910444e−21C44−2.87133882e−235.71789768e−18−1.52076385e−23C469.04401197e−2700C483.06652794e−2600C503.95339353e−2600C522.12427278e−2600C546.19479308e−2700C55−9.56418704e−2900C57−4.73070844e−2800C59−9.34446589e−2800C61−9.13157935e−2800C63−4.41677071e−2800C65−7.86181975e−2900 TABLE 3b for FIG. 7CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−743.46091320−835.77975520−5551.96069600C78.15313049e−071.08411968e−06 8.1725158e−08C91.15936905e−072.66713006e−072.11082779e−08C10−2.17231701e−091.97364815e−09−7.51877121e−09C122.45410579e−09 1.29311988e−099.83512366e−10C148.78996519e−10 1.55808687e−08 −1.39425604e−10C16−1.4388317e−11−7.24177347e−121.61763526e−11C182.43340771e−12 3.70702943e−121.05071826e−12C208.01706893e−12−2.73262347e−10−1.62527109e−13C212.02931387e−14−9.2131432e−153.04337357e−13C23−2.63254556e−145.85039506e−14 −7.58462902e−14C25−5.41315246e−15−3.84690423e−13 −1.81428849e−15C276.80497633e−14 4.35189326e−12 −7.18902516e−16C29−7.38761627e−184.09273025e−17−1.95967055e−15C31−1.6406802e−16−1.32466527e−152.23232144e−16C33 4.6161003e−17 1.11389945e−141.45669424e−17C353.46981394e−16−8.00414961e−14−5.3737245e−19C366.56861624e−193.51522585e−21−3.51163866e−17C382.53098962e−195.30473647e−20 8.4177008e−18C40−1.17789383e−181.14555302e−174.49375372e−19C427.13915336e−19−1.10798161e−16−2.61682976e−20C446.00248794e−196.75342377e−162.31069209e−21 TABLE 3c for FIG. 7CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−1728.90769600 −880.94474610C73.08450816e−06−4.70279039e−08C9−2.17253795e−081.08990881e−07C10−3.75473915e−08−3.45672808e−11C12−1.81552974e−082.73887057e−11C147.96803985e−11−4.28414412e−10C16 2.0647621e−102.40236171e−14C187.22424709e−11−6.19613419e−13C201.47510283e−121.08423073e−12C211.77572753e−12−1.52199951e−17C23−6.59234699e−14−1.8034018e−15C25−2.26260751e−13−3.76723043e−15C27−5.706268e−15−5.40832792e−15C29−2.77294786e−14−2.49126053e−19C31−4.84971158e−15−3.60876052e−18C333.35099874e−161.99785264e−18C352.39450375e−178.80558903e−18C362.21806273e−16−5.44564635e−22C381.36037517e−16−4.37847046e−20C402.00582463e−17−7.42210048e−20C421.83054058e−19−1.69927808e−19C44−5.75280548e−201.02060681e−19 TABLE 4a for FIG. 7SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.00000000764.50361369M70.0000000096.8265245764.27191627M60.00000000−27.928475031058.54662453M50.00000000−219.640545591392.20908570M40.00000000−271.243881311813.78075704Stop0.00000000−198.321568861677.53219215M30.00000000−128.241792161546.81115682M20.0000000016.783572341430.95006703100.000000008791.56176690−7122.00998575M10.00000000272.34233418956.66066528Object plane0.00000000362.681806361900.18311637 TABLE 4b for FIG. 7SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M83.915969260.00000000−0.00000000M7187.391868360.00000000−0.00000000M6−71.507149960.00000000−0.00000000M5108.420163730.00000000−0.00000000M417.563971970.00000000−0.00000000Stop−36.240966930.00000000−0.00000000M3129.752520180.00000000−0.00000000M2−50.204994660.00000000−0.0000000010135.943181240.00000000−0.00000000M1191.414610480.00000000−0.00000000Object plane−0.000000000.00000000−0.00000000 TABLE 5 for FIG. 7SurfaceAngle of incidence [deg]ReflectivityM83.915969260.66415239M70.355854610.66566616M678.628979530.85974012M578.560000020.85877563M410.588064230.65325493M378.417634670.85677489M278.469876380.85751067M116.881793120.63082790Overall transmission0.0988 TABLE 6 for FIG. 7X[mm]Y[mm]Z[mm]0.00000000−47.763893830.000000000.75722478−47.214909440.000000001.44466231−45.564408650.000000001.99925630−42.806168530.000000002.37083821−38.943149490.000000002.52737588−34.002999200.000000002.45862703−28.051536570.000000002.17710208−21.199179060.000000001.71593988−13.599136060.000000001.12445586−5.439439180.000000000.462492913.067949660.00000000−0.2055757511.697672120.00000000−0.8166656420.219433250.00000000−1.3143367528.404877220.00000000−1.6535440236.033727300.00000000−1.8046032242.898988160.00000000−1.7560528348.811111760.00000000−1.5160286953.602290920.00000000−1.1118425357.132130520.00000000−0.5876124759.294316170.00000000−0.0000000060.022548860.000000000.5876124759.294316170.000000001.1118425357.132130520.000000001.5160286953.602290920.000000001.7560528348.811111760.000000001.8046032242.898988160.000000001.6535440236.033727300.000000001.3143367528.404877220.000000000.8166656420.219433250.000000000.2055757511.697672120.00000000−0.462492913.067949660.00000000−1.12445586−5.439439180.00000000−1.71593988−13.599136060.00000000−2.17710208−21.199179060.00000000−2.45862703−28.051536570.00000000−2.52737588−34.002999200.00000000−2.37083821−38.943149490.00000000−1.99925630−42.806168530.00000000−1.44466231−45.564408650.00000000−0.75722478−47.214909440.00000000 An overall reflectivity of the projection optical unit 24 is 9.88%. The projection optical unit 24 has a reducing imaging scale of 8×(β=8). The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 0.8 mm. The projection optical unit 24 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. In the projection optical unit 24, a pupil plane 18 is arranged in the beam path of the imaging light 3 between the mirrors M2 and M3. An intermediate image plane 19 is arranged in the imaging beam path between the mirrors M4 and M5. The mirrors M1, M3, M4, M6 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The mirrors M2, M5 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M3, M5 and M6 have very large absolute radii, i.e. only constitute small deviations from plane reflection surfaces. It is also the case in the projection optical unit 24 that only the last mirror M8 includes a passage opening 17 in the imaging beam path for the imaging light 3 guided between the mirrors M6 and M7. An installation length of the projection optical unit 24 in the z-direction, i.e. a distance between the object plane 5 and the image plane 9, is 1900 mm. The mirror M8 has the largest diameter of all mirrors in the projection optical unit 24, the diameter lying in the region of 700 mm. In the projection optical unit 24, an object/image offset dOIS is approximately 360 mm. In the projection optical unit 24, the object field-side chief rays 16 also include an angle CRAO of 5.5° with a normal of the object plane 5. The projection optical unit 24 has a scanned RMS value of the image field-side wavefront which is in the region of 100 mλ. An image field-side distortion value is in the region of 0.6 nm in the projection optical unit 24. An aperture stop effective for the y-dimension can be arranged in the beam path of the imaging light 3 between the mirrors M2 and M3. In the projection optical unit 24, the chief rays 16 of the imaging light 3 propagate divergently between the object field 4 and the mirror M1. The mirror M8 defines an image-side obscuration which in the x-dimension is less than 24% of the image-side numerical aperture of the projection optical unit 24. In the y-direction, the obscuration is significantly smaller and moreover decentered. A further embodiment of a projection optical unit 25, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 8. Components and functions which were already explained above in the context of FIGS. 1 to 7 are appropriately denoted by the same reference signs and are not discussed again in detail. The imaging beam path of the projection optical unit 25 corresponds qualitatively to that of the projection optical units 23 and 24 according to FIGS. 6 and 7. The projection optical unit 25 also includes eight mirrors M1 to M8, of which the mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence and the mirrors M2, M3, M5 and M6 are embodied as mirrors for grazing incidence. The deflecting effects of the mirrors M2 and M3 on the one hand, and M5 and M6 on the other hand are subtracted from one another. The mirrors M1 to M8 are configured as free-form surfaces, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 25 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 8Exemplary embodimentFIG. 8NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.784mmField curvature0.01/mmStopS9 TABLE 2 for FIG. 8SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−1049.603896410.00189993−986.014372310.00203430REFLM71052.05094258−0.00190085516.30074958−0.00387413REFLM6672.07102892−0.000594086476.96591445−0.00154677REFLM5−799.229899680.00049907−9635.871453090.00104073REFLM4−655.821006640.00302260−1132.347380460.00178202REFLM32083.13733086−0.00019163−8161.780023890.00122769REFLM2—0.000012242513.72027155−0.00398819REFLM1−1124.779273520.00171284−993.832774530.00208912REFL TABLE 3a for FIG. 8CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−1049.603896001052.05094300672.07102890C78.94830424e−096.82707408e−085.39977203e−07C93.00569958e−09 5.0133583e−08 5.0463779e−08C10−1.0205043e−119.13305341e−102.96374987e−09C12−1.78212052e−112.88849001e−093.61953024e−09C14−6.16611869e−121.70930306e−09 9.8625888e−11C165.53369586e−156.46391137e−131.62428612e−11C187.14785588e−151.61691667e−126.55853805e−12C20 1.2952174e−15−1.12568271e−139.89173718e−14C21−1.15962082e−17 3.2230907e−152.17786681e−14C23−3.29641744e−171.94684249e−147.78862843e−14C25−2.88253574e−17 2.8363428e−142.06500061e−14C27−7.61491275e−189.96975622e−155.79706038e−17C293.95947425e−214.40316043e−181.76578906e−16C319.59189e−213.61186907e−171.59804916e−16C33 5.9075341e−212.40890432e−174.63612518e−17C354.91436138e−22−2.08227139e−17−1.15451621e−18C36−9.78221988e−242.17340086e−204.62607032e−20C38−3.80396711e−231.769269e−192.36610599e−19C40−5.3008359e−235.27416888e−193.60474258e−19C42−3.05920471e−233.79026666e−19 8.8347498e−20C44−6.20613311e−24−4.57440157e−20−2.35018949e−21C464.59926677e−2700C481.58065492e−2600C501.76803708e−2600C527.68522982e−2700C545.34537619e−2800C55−1.6671251e−2900C57−8.60661791e−2900C59−1.74742916e−2800C61−1.71631988e−2800C63−7.97461918e−2900C65−1.37837693e−2900 TABLE 3b for FIG. 8CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−799.22989970−655.821006602083.13733100C7−2.06359045e−071.79769856e−06−1.23888727e−06C94.53272901e−082.37465306e−068.86422249e−08C104.98518606e−10−1.48557245e−09−3.40006344e−09C12−1.31134892e−09−2.80514774e−102.03241635e−09C142.98465492e−123.01097166e−09−3.36768492e−11C164.49053513e−123.15577912e−11−1.66141091e−11C181.64207121e−127.30259248e−11−7.13724906e−12C20−1.0335036e−12 .09731752e−105.4031591e−13C21−2.93206259e−14−2.05672375e−14−4.18881657e−13C23−5.92456689e−142.22350106e−14−6.83276534e−14C25−5.80080861e−141.08931865e−12−7.07864185e−15C27 2.2172926e−14 −1.42234054e−125.63121269e−16C291.40438563e−178.53769578e−16−8.08308771e−16C31−6.66032602e−17 2.70533891e−152.67861368e−16C337.30170261e−16−1.62676517e−15−3.42472444e−17C353.16423462e−164.49594522e−141.66873362e−18C36−1.81264397e−18−3.66571047e−19−6.54742071e−17C38−5.39055928e−20−3.12546568e−184.62927488e−18C40−2.02947052e−187.95440303e−17−4.8710506e−18C42−2.24011839e−186.67587526e−16−2.67955705e−19C44−7.82360967e−183.07878704e−162.12454918e−22 TABLE 3c for FIG. 8CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−32587.82702000−1124.77927400C7−4.74483513e−072.20095584e−09C93.93556671e−081.960322e−07C10−2.66024165e−09−2.88589459e−11C12−2.10042981e−09−1.13714912e−11C14−4.96647358e−11−1.87229835e−10C163.63968975e−11 −1.00857126e−13C18−6.32882695e−12−1.48327939e−14C201.40830966e−121.42850505e−12C21−3.43617167e−13−3.03067897e−17C232.78640456e−15 −3.68437637e−16C25−2.10521417e−142.77481379e−15C27−3.31782506e−16−2.91734364e−15C293.53276862e−155.08698618e−19C31−7.40107603e−167.73915869e−18C332.47602209e−17−6.54164067e−19C353.81467272e−181.85860304e−17C36−5.81173248e−181.22184892e−21C38−1.24881103e−171.12627739e−20C406.79836244e−183.74180742e−20C42−6.71427793e−193.54376196e−20C442.7467903e−20 −9.46214624e−20 TABLE 4a for FIG. 8SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.00000000921.48007420M70.00000000 127.6965136091.87626879M60.00000000 −54.515245831081.95671536M50.0000000020.291142221416.57838942M40.00000000 −58.318894201844.49683317M30.0000000059.416299681599.41318117M20.00000000 224.001887681454.69416858Stop0.00000000 273.524666231404.16528501M10.00000000 493.26104418894.61377093Object plane0.00000000589.570097991900.28701404 TABLE 4b for FIG. 8SurfaceTLA [deg]TLB [deg]TLC [deg]Image plane−0.000000000.00000000−0.00000000M84.376159320.00000000−0.00000000M7189.593636000.00000000−0.00000000M688.913652070.00000000−0.00000000M5268.902180870.00000000−0.00000000M418.038606360.00000000−0.00000000M3127.179472720.00000000−0.00000000M2−52.811274020.00000000−0.00000000Stop206.027711280.00000000−0.00000000M1190.103763440.00000000−0.00000000Object plane−0.000000000.00000000−0.00000000 TABLE 5 for FIG. 8SurfaceAngle of incidence [deg]ReflectivityM84.376159320.66374698M70.838455170.66562989M678.484513360.85771648M578.496046500.85787855M47.631153840.65946494M378.486536320.85774492M278.492425580.85782768M115.574175940.63670200Overall transmission0.1004 TABLE 6 for FIG. 8X[mm]Y[mm]Z[mm]0.0000000047.813039700.00000000−5.4442927747.461754970.00000000−10.7451728646.422202290.00000000−15.7639116044.736363570.00000000−20.3708896042.471219050.00000000−24.4494662139.714514890.00000000−27.8990730236.569337100.00000000−30.6374981433.148088750.00000000−32.6024306529.566536660.00000000−33.7523138725.938353920.00000000−34.0665677722.370331800.00000000−33.5452945218.958376280.00000000−32.2085489015.784387870.00000000−30.0951880212.914069770.00000000−27.2613606810.395742440.00000000−23.778787968.260361800.00000000−19.732959486.522965090.00000000−15.221255955.185626810.00000000−10.350953054.241758230.00000000−5.237067753.681248860.00000000−0.000000003.495518440.000000005.237067753.681248860.0000000010.350953054.241758230.0000000015.221255955.185626810.0000000019.732959486.522965090.0000000023.778787968.260361800.0000000027.2613606810.395742440.0000000030.0951880212.914069770.0000000032.2085489015.784387870.0000000033.5452945218.958376280.0000000034.0665677722.370331800.0000000033.7523138725.938353920.0000000032.6024306529.566536660.0000000030.6374981433.148088750.0000000027.8990730236.569337100.0000000024.4494662139.714514890.0000000020.3708896042.471219050.0000000015.7639116044.736363570.0000000010.7451728646.422202290.000000005.4442927747.461754970.00000000 An overall reflectivity of the projection optical unit 25 is 10.04%. The projection optical unit 25 has a reducing imaging scale of 8×(β=8). The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1 mm. The projection optical unit 25 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The mirrors M1, M3, M4, M5 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The mirrors M2, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M3, M5 and M6 have very large absolute radii, i.e. only constitute small deviations from plane reflection surfaces. It is also the case in the projection optical unit 25 that only the last mirror M8 includes a passage opening 17 for the imaging light 3 guided between the mirrors M6 and M7. In the projection optical unit 25, a pupil plane 18 is arranged between the mirror M2 and the mirror M3. In the projection optical unit 25, an intermediate image plane 19 is arranged in the region of the reflection on the mirror M5 for grazing incidence. In the projection optical unit 25, a z-distance between the object plane 5 and the image plane 9 is 1900 mm. In the projection optical unit 25, a typical diameter of the largest mirror M8 is approximately 800 mm. In the projection optical unit 25, an object/image offset dOIS is approximately 600 mm. In the projection optical unit 25, the object field-side chief rays 16 also include an angle CRAO of 5.5° with a normal of the object plane 5. The projection optical unit 25 has a scanned RMS value of the image field-side wavefront which is approximately 70 mλ. An image field-side distortion value is approximately 3 nm in the projection optical unit 25. In the projection optical unit 25, an aperture stop can be arranged in the beam path of the imaging light 3 between the mirrors M2 and M3. In the projection optical unit 25, the chief rays 16 propagate divergently between the object field 4 and the mirror M1. The mirror M8 defines an image-side obscuration which in the x-dimension is less than 20% of the image-side numerical aperture of the projection optical unit 25. In the y-direction, the obscuration is significantly smaller and moreover decentered. A further embodiment of a projection optical unit 26, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 9. Components and functions which were already explained above in the context of FIGS. 1 to 8 are appropriately denoted by the same reference signs and are not discussed again in detail. The projection optical unit 26 has a total of eight mirrors M1 to M8. These are configured as free-form surfaces, for which the free-form surface equation (1), specified above, applies. The imaging beam path of the projection optical unit 26 corresponds qualitatively to that of the projection optical unit 7, mirrored about a plane parallel to the xz-plane. The mirrors M2 and M3 on the one hand, and M5 and M6 on the other hand once again constitute pairs of mirrors for grazing incidence, the deflecting effect of which for the imaging light adds up. The other mirrors M1, M4, M7 and M8 are mirrors for normal incidence. The optical design data from the projection optical unit 26 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 9Exemplary embodimentFIG. 9NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.784mmField curvature0.01/mmStopS8 TABLE 2 for FIG. 9SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8—0.00195413−933.335497870.00214871REFLM71354.53748928−0.00147651452.31842933−0.00442170REFLM6—0.0003447215664.51705589−0.00052721REFLM53999.20552730−0.000078867254.86511412−0.00174817REFLM4—0.00164064−894.728029280.00230144REFLM34681.74323636−0.000076535171.50582521−0.00215877REFLM2 852.69172547−0.00067816—0.00062397REFLM1—0.00097408−2270.564878940.00092083REFL TABLE 3a for FIG. 9CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−1020.684739001354.53748900−1405.06283600C7−4.5731683e−10−3.41690693e−07−5.65649344e−08C92.45996777e−09 3.83206678e−081.89544462e−09C10−9.85395846e−126.44749036e−10−1.93920244e−10C12−2.34897758e−112.85639184e−09−3.25598414e−11C14−8.72926178e−123.07364292e−09−1.12164645e−13C166.07361769e−16−3.09291494e−13 3.36943064e−12C182.41094328e−15 2.31337277e−13 6.29413154e−13C201.32110071e−151.3381722e−12 1.29643368e−13C21−1.23303721e−171.38415935e−15 4.62316004e−14C23−4.20277144e−171.20452307e−14 8.27538418e−15C25−4.08488297e−173.55373943e−14 8.69367918e−16C27−1.08210387e−171.90903669e−14 9.15499041e−18C291.07931282e−21−1.26240025e−19−1.09629551e−16C313.53989366e−21 7.87268568e−18−2.60340852e−19C333.24535646e−21 3.94705236e−17−1.56739759e−18C351.50192167e−216.62304e−17 −1.72905085e−19C36−1.14892505e−236.66100206e−211.66079634e−18C38−5.06654961e−238.27654198e−20 8.50117627e−20C40−7.8424464e−23 4.19476166e−19−1.05681234e−19C42−4.9856421e−23 8.00362496e−19 −5.2250027e−21C44−1.06579309e−235.55709617e−19 1.40460138e−22C462.08122398e−2700C486.60530624e−2700C507.61977765e−2700C524.50302264e−2700C541.39426672e−2700C55−2.0882185e−2900C57−1.18627262e−2800C59 −2.58588211e−2800C61 −2.72003773e−2800C63−1.3620868e−2800C65 −2.53756018e−2900 TABLE 3b for FIG. 9CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX3999.20552700−1184.012278004681.74323600C78.69357878e−08 7.62650744e−09 1.82926331e−07C9−2.20256023e−08−6.79819355e−07−2.74549952e−08C106.23391082e−10−6.30875708e−111.36557421e−10C122.15155751e−106.40787678e−12 5.55467106e−10C146.51961859e−11−3.52233076e−09 1.76746757e−10C168.39711467e−13−2.68662388e−14 1.76890882e−12C182.30182337e−13−1.32962452e−12−4.71589056e−13C20−4.46761962e−14−2.08675862e−111.39910872e−13C21−4.34103393e−15−6.57999966e−17−1.21518032e−14C233.68657946e−15−8.04594597e−16 9.50534732e−15C251.89166259e−16−3.29911674e−15−8.40961008e−15C271.06520031e−16−1.32487137e−13−8.07445146e−15C291.3373458e−17 9.49001529e−196.03691731e−18C311.69029919e−17−8.32008838e−18 9.40385193e−17C332.62169884e−18 8.1099079e−171.1838444e−16C35−3.09635883e−19−1.03894539e−15 9.19224029e−17C363.39460047e−19−9.69222081e−22 1.64007551e−19C381.19302799e−19 1.76179484e−21 6.27204932e−20C406.54223006e−20 1.83258474e−20−4.59136703e−19C42−4.52075866e−21 1.01522211e−18−4.92528089e−19C447.14188701e−22−5.99497164e−18−3.46025607e−19 TABLE 3c for FIG. 9CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX852.69172550−1964.03237500C7−7.81658255e−07−4.55147095e−09C91.56377907e−09−5.53517249e−08C105.58543355e−10−6.87418275e−12C121.03807562e−09 −1.8936292e−11C14−7.16700901e−13 2.34208295e−10C16−2.34728814e−12 2.34056772e−14C18−1.28373035e−121.87499703e−13C20−7.57748125e−15 −8.87948384e−13C21−1.15979439e−15 1.42512308e−18C234.32890616e−152.07491865e−17C251.60432619e−15−9.62467925e−16C272.85253744e−182.00812e−15C293.98866926e−181.34308944e−20C31−4.89809284e−18 −1.00614084e−19C33−1.71062114e−18 4.24046777e−18C357.20763643e−21−2.92886467e−18C366.42255749e−21−3.18411183e−24C38−3.70862193e−21 −1.94058082e−23C403.05690863e−219.71214773e−22C421.05972674e−21−7.95009632e−21C44−1.21554754e−23 6.09195055e−21 TABLE 4a for FIG. 9SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.00000000865.29422222M70.00000000118.5249092468.26504872M60.00000000−36.784877791055.95508411M50.00000000−363.530356761490.07075809M40.00000000−730.264413011745.75557040M30.00000000−69.289790051660.49873728Stop0.00000000343.229619491432.58044567M20.00000000752.016781321223.96788517M10.000000001204.58566704386.83503296Object plane0.000000001351.261443441909.74496129 TABLE 4b for FIG. 9SurfaceTLA [deg]TLB [deg]TLC [deg]Image plane−0.000000000.00000000−0.00000000M84.22991607 0.00000000−0.00000000M7188.701259980.00000000−0.00000000M6−67.047447210.00000000−0.00000000M5−43.959276600.00000000−0.00000000M468.882424680.00000000−0.00000000M3−17.671199690.00000000−0.00000000Stop−59.234772570.00000000−0.00000000M2−44.797016530.00000000−0.00000000M1191.447740200.00000000−0.00000000Object plane−0.000000000.00000000−0.00000000 TABLE 5 for FIG. 9SurfaceAngle of incidence [deg]ReflectivityM84.229916070.66388105M70.238832750.66566686M675.984943770.82019012M580.926872100.89027623M413.767469940.64369696M379.679973950.87406508M273.194150340.77128309M116.948929100.63050655Overall transmission0.0883 TABLE 6 for FIG. 9X[mm]Y[mm]Z[mm]0.00000000−80.470934170.00000000−10.25746907−79.949870760.00000000−20.26826613−78.372107650.00000000−29.79066890−75.697972140.00000000−38.59312691−71.874063470.00000000−46.45979046−66.850284670.00000000−53.19615576−60.600066020.00000000−58.63447748−53.13981514−0.00000000−62.63850784−44.543148910.00000000−65.10719435−34.947242920.00000000−65.97718636−24.551388030.00000000−65.22420672−13.609792940.00000000−62.86345402−2.421341930.00000000−58.949216688.681428220.00000000−53.5738198619.343275300.00000000−46.8659208129.197978840.00000000−38.9880654537.882609010.00000000−30.1333657445.05554784−0.00000000−20.5211820450.41779081−0.00000000−10.3917755253.735191550.00000000−0.0000000054.858151750.0000000010.3917755253.73519155−0.0000000020.5211820450.417790810.0000000030.1333657445.05554784−0.0000000038.9880654537.882609010.0000000046.8659208129.197978840.0000000053.5738198619.343275300.0000000058.949216688.681428220.0000000062.86345402−2.421341930.0000000065.22420672−13.609792940.0000000065.97718636−24.551388030.0000000065.10719435−34.947242920.0000000062.63850784−44.543148910.0000000058.63447748−53.13981514−0.0000000053.19615576−60.600066020.0000000046.45979046−66.850284670.0000000038.59312691−71.874063470.0000000029.79066890−75.697972140.0000000020.26826613−78.37210765−0.0000000010.25746907−79.949870760.00000000 An overall reflectivity of the projection optical unit 26 is 8.83%. The projection optical unit 26 has a reducing imaging scale of 8×(β=8). The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1 mm. The projection optical unit 26 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The mirrors M1, M2, M4 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The mirrors M3, M5, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 have very large absolute radii, i.e. only constitute small deviations from plane reflection surfaces. A pupil plane 18 of the projection optical unit 26 lies in the beam path between the mirrors M2 and M3. Unlike what is schematically indicated in FIG. 9, this stop plane is tilted in relation to a chief ray of the central field point. An intermediate image plane 19 of the projection optical unit 26 lies in the region of a reflection on the mirror M3. It is also the case in the projection optical unit 26 that the mirror M8 is the only mirror including a passage opening 17 in the imaging beam path for the imaging light 3 between the mirrors M6 and M7. In the projection optical unit 26, a z-distance between the object plane 5 and the image plane 9 is 1900 mm. In the projection optical unit 26, a typical diameter of the largest mirror M8 is approximately 800 mm. In the projection optical unit 26, an object/image offset dOIS is approximately 1350 mm. In the projection optical unit 26, the object field-side chief rays 16 also include an angle CRAO of 5.5° with a normal of the object plane 5. The projection optical unit 26 has a scanned RMS value of the image field-side wavefront which is approximately 30 mλ. An image field-side distortion value is approximately 1.0 nm in the projection optical unit 26. In the projection optical unit 26, a stop effective for the x-direction can be arranged in the beam path of the imaging light 3 between the mirrors M1 and M2 and a stop effective for the y-dimension can be arranged in the beam path between the mirrors M2 and M3. In the projection optical unit 26, the chief rays 16 propagate divergently in the beam path of the imaging light 3 between the object field 4 and the mirror M1. The mirror M8 defines an image-side obscuration which in the x-dimension is less than 20% of the image-side numerical aperture of the projection optical unit 26. In the y-direction, the obscuration is significantly smaller and moreover decentered. A further embodiment of a projection optical unit 27, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 10. Components and functions which were already explained above in the context of FIGS. 1 to 9 are appropriately denoted by the same reference signs and are not discussed again in detail. The projection optical unit 27 has a total of nine mirrors M1 to M9. The mirrors M1, M3, M5, M6 and M7 are embodied as mirrors for grazing incidence. The mirrors M2, M4, M8 and M9 are embodied as mirrors for normal incidence. After the reflection on the mirror M1, the imaging beam path of the projection optical unit 27 corresponds qualitatively to that of the projection optical unit 26 before the reflection on the mirror M1 located there. Unlike in the projection optical unit 26, the object plane 5 and the image plane 9 in the projection optical unit 27 do not extend parallel to one another, but rather have an angle with respect to one another. The angle between the object plane 5 and the image plane 9 is approximately 25°. A different angle between object plane 5 and the image plane 9 is also possible, for example an angle of 9°. The mirrors M1 to M9 are embodied as free-form surfaces, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 27 can be gathered from the following tables, which, in terms of their design, correspond to the tables in relation to the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 10Exemplary embodimentFIG. 10NA0.45Wavelength13.5nmField dimension x13.0mmField dimension y0.784mmField curvature0.01/mmStopS8 TABLE 2 for FIG. 10SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM9−927.061632410.00215195−844.375531020.00237456REFLM81260.16184110−0.00158703401.08562452−0.00498668REFLM7−1168.044135880.0004010711410.61912595−0.00074830REFLM64599.68965912−0.000067828916.30231166−0.00143804REFLM5−1096.769715490.00176717−863.865892350.00238902REFLM44376.93959430−0.000088264854.36195700−0.00213313REFLM3694.47986096−0.00078202−11204.910729860.00065732REFLM2−1794.723408190.00106428−2029.306308950.00103195REFLM156094.16071744−0.000006192455768.87767400−0.00000469REFL TABLE 3a for FIG. 10CoefficientM9M8M7KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−927.061632401260.16184100−1168.04413600C7−2.23517614e−09−4.50960587e−07−6.09122113e−08C93.6145057e−092.20913057e−07 −7.41514642e−09C10−1.30846827e−118.26856896e−10−4.23871389e−10C12−3.31679633e−113.96892634e−09 −8.1925409e−11C14−1.11333628e−113.96037785e−09 5.90888948e−12C16−1.35234341e−15−7.57597915e−133.35805375e−12C182.4979396e−157.50962025e−13 5.21136649e−13C202.05872696e−15 1.71669679e−12 1.05276252e−13C21−1.94087173e−17 1.87848046e−15 8.25497656e−14C23−7.12735855e−17 2.02345088e−14 1.69291777e−14C25−6.73063611e−17 5.75563235e−14 1.53606778e−15C27−1.82798337e−17 5.09562952e−14 3.54149717e−17C29−3.20697386e−24−7.22215501e−19−3.97944158e−16C313.5532586e−212.1496672e−17−2.2247379e−17C335.38887498e−21 6.98750447e−171.44225902e−18C352.90441791e−21 1.60217048e−16 2.10047652e−19C36−2.16831662e−23 1.02346305e−20 7.76582807e−18C38−1.024839e−221.50853153e−19 2.1988537e−18C40−1.5739648e−22 7.95625269e−198.70609334e−20C42−9.99598149e−231.67352786e−183.47122436e−22C44−2.1418847e−23 1.35065244e−18 −3.9650949e−23C461.75635066e−2700C483.95925628e−2700C509.08959768e−2700C527.51947576e−2700C542.95311155e−2700C55−4.9313257e−2900C57−2.91657271e−2800C59−6.40825581e−2800C61−6.7271506e−2800C63−3.36939719e−2800C65−6.32994338e−2900 TABLE 3b for FIG. 10CoefficientM6M5M4KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX4599.68965900−1096.769715004376.93959400C71.03365575e−071.77442565e−082.85338602e−07C9−1.54020378e−08−6.87485517e−07−1.50086102e−08C106.24726933e−10−6.07852311e−11−2.45993749e−10C122.40839743e−10 5.8774529e−11 7.01376961e−10C145.40400123e−11 −4.141262e−09 2.22502751e−10C168.59548973e−13 6.15732667e−143.90716877e−12C183.88970513e−13−1.96817792e−12−8.40526435e−13C20−4.05623477e−14−2.89315132e−114.02410751e−13C21−1.20558697e−14 2.96793339e−17−3.71431043e−14C233.60545789e−15−1.07466885e−152.86503345e−14C254.90623123e−16−7.66590675e−15−1.34184278e−14C271.09460213e−16−2.25511385e−13−1.60120001e−14C29−4.29010487e−192.6566245e−18 −1.11931312e−16C312.82057928e−17−4.89526911e−181.96219169e−16C333.64606722e−18 1.17410302e−161.62404628e−16C35−1.9616745e−19−1.76366177e−152.00776571e−16C364.55297641e−19−1.10261165e−212.17082945e−21C381.72685649e−194.71570588e−21−1.71177213e−19C401.19053297e−191.68707682e−19−5.48323926e−19C422.84505286e−211.74228055e−18−7.77652616e−19C443.95736521e−22−8.4090687e−18−8.35475752e−19 TABLE 3c for FIG. 10CoefficientM3M2M1KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX694.47986100−1794.7234080056094.16072000C7−9.05001362e−072.43898758e−08−4.50372077e−08C93.15550349e−09−3.56700561e−08−1.70664296e−09C106.34026502e−109.89791173e−13−4.70024759e−11C121.18596959e−09−6.80752791e−11 −1.3238749e−11C141.06817193e−12 2.4496293e−105.60439886e−14C16−3.63455516e−12−5.25512666e−15 1.47433739e−13C18−1.41249895e−124.60707008e−132.95667054e−14C20−1.74617944e−14−1.2047971e−124.8002619e−15C21−1.91218475e−15−2.29258544e−181.9028315e−16C237.60619654e−15 1.4721488e−163.97100834e−16C251.76329071e−15−2.52607323e−15 5.02793845e−17C271.20304383e−172.91792964e−151.19507083e−17C296.27376885e−18 6.5563985e−207.22310933e−20C31−9.91733853e−18−8.95631485e−19 3.50704599e−19C33−2.07433776e−188.24988356e−186.30478322e−20C358.04274126e−21−6.16363923e−18 1.42780131e−20C361.68635395e−20−3.79475169e−23 1.84200486e−21C38−2.47873133e−21−5.38421564e−22−8.43097684e−22C407.02632851e−211.78624244e−211.73741471e−22C421.58722416e−21−1.78993463e−20 3.02938088e−23C44−3.21703854e−235.70718198e−217.7900247e−24 TABLE 4a for FIG. 10SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M90.000000000.00000000786.63111111M80.00000000102.6383416266.28304947M70.00000000−42.20392704963.45589840M60.00000000−330.288702871356.10968115M50.00000000−662.926506711595.87409890M40.00000000−55.873863631518.97310352Stop0.00000000312.026926811302.34585970M30.00000000677.249569831104.30311012M20.000000001096.20099718348.22303178M10.000000001163.417928261046.10952756Object plane−0.00000000990.097333231716.14318698 TABLE 4b for FIG. 10SurfaceTLA [deg]TLB [deg]TLC [deg]Image plane−0.000000000.00000000−0.00000000M94.056657610.00000000−0.00000000M8188.651276450.00000000−0.00000000M7−67.279425500.00000000−0.00000000M6−44.759344040.00000000−0.00000000M568.497637550.00000000−0.00000000M4−18.356889660.00000000−0.00000000Stop−59.234772570.00000000−0.00000000M3−45.249654450.00000000−0.00000000M2191.746713180.00000000−0.00000000M1−85.49756738−0.00000000180.00000000Object plane9.00279525−0.00000000180.00000000 TABLE 5 for FIG. 10SurfaceAngle of incidence [deg]ReflectivityM94.056657610.66403357M80.530441480.66565924M776.453626130.82762443M681.026268530.89153746M514.282465330.64182800M478.863694900.86299856M374.243631690.79067680M217.246088990.62906014M179.999382090.87829176Overall transmission0.0789 TABLE 6 for FIG. 10X[mm]Y[mm]Z[mm]0.00000000−77.368996260.00000000−9.63805104−76.891749320.00000000−19.04585126−75.446034980.00000000−27.99720457−72.993791200.00000000−36.27449492−69.483698540.00000000−43.67382900−64.867134060.00000000−50.01062298−59.116554500.00000000−55.12523420−52.242780880.00000000−58.88805408−44.307711000.00000000−61.20346679−35.430472650.00000000−62.01235694−25.787157670.00000000−61.29323966−15.605858440.00000000−59.06229034−5.159177590.00000000−55.372543265.244259820.00000000−50.3124844915.269103130.00000000−44.0041925824.564505520.00000000−36.6009866532.778840300.00000000−28.2843478439.578602450.00000000−19.2598996944.670511830.00000000−9.7524185347.824252570.00000000−0.0000000048.892422000.000000009.7524185347.824252570.0000000019.2598996944.670511830.0000000028.2843478439.578602450.0000000036.6009866532.778840300.0000000044.0041925824.564505520.0000000050.3124844915.269103130.0000000055.372543265.244259820.0000000059.06229034−5.159177590.0000000061.29323966−15.605858440.0000000062.01235694−25.787157670.0000000061.20346679−35.430472650.0000000058.88805408−44.307711000.0000000055.12523420−52.242780880.0000000050.01062298−59.116554500.0000000043.67382900−64.867134060.0000000036.27449492−69.483698540.0000000027.99720457−72.993791200.0000000019.04585126−75.446034980.000000009.63805104−76.891749320.00000000 An overall reflectivity of the projection optical unit 27 is 7.89%. The projection optical unit 27 has a reducing imaging scale of 8×(β=8). The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1 mm. The projection optical unit 27 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. In the projection optical unit 27, a pupil plane 18 is arranged in the imaging beam path between the mirrors M3 and M4. Unlike what is depicted schematically, the pupil plane 18 is tilted in relation to a chief ray of the central field point. An intermediate image plane 19 is arranged in the imaging beam path between the mirrors M4 and M5, near the mirror M4. In the projection optical unit 27, the mirrors M3 and M4 on the one hand and M6 and M7 on the other hand form pairs of mirrors for grazing incidence, the deflecting effect of which on the imaging light 3 adds up. The mirrors M1, M4, M6, M7 and M8 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M9 have negative values for the radius, i.e. are, in principle, concave mirrors. The mirrors M1, M3, M4, M6 and M7 have very large absolute radii, i.e. only constitute small deviations from plane reflection surfaces. It is in turn the case in the projection optical unit 27 that the mirror M9 is the only mirror including a passage opening 17 for the passage of the imaging light 3 guided between the mirrors M7 and M8. In the projection optical unit 27, a z-distance between the object plane 5 and the image plane 9 is approximately 1700 mm. In the projection optical unit 27, a typical diameter of the largest mirror M9 is approximately 730 mm. In the projection optical unit 27, an object/image offset dOIS is approximately 1000 mm. In the projection optical unit 27, the object field-side chief rays 16 also include an angle CRAO of 5.5° with a normal of the object plane 5. The projection optical unit 27 has a scanned RMS value of the image field-side wavefront which is approximately 30 mλ. An image field-side distortion value is approximately 0.6 nm in the projection optical unit 27. A stop effective for the x-dimension can be arranged in the beam path of the imaging light 3 between the mirrors M2 and M3. In the projection optical unit 27, a stop effective for the y-dimension can be arranged in the beam path between the mirrors M3 and M4. Chief rays 16 in the projection optical unit 27 have a divergent propagation in the beam path of the imaging light 3 between the object field 4 and the mirror M1. The mirror M9 defines an image-side obscuration which, over the x-dimension, is less than 20% of the image-side numerical aperture of the projection optical unit 27. In the y-direction, the obscuration is significantly smaller and moreover decentered. A further embodiment of a projection optical unit 28, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 11. Components and functions which were already explained above in the context of FIGS. 1 to 10 are appropriately denoted by the same reference signs and are not discussed again in detail. The projection optical unit 28 has a total of eight mirrors M1 to M8. The mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence. The mirrors M2, M3, M5 and M6 are embodied as mirrors for grazing incidence. After the mirror M4, the beam path in the projection optical unit 28 corresponds qualitatively to the beam path after the mirror M5 in the projection optical unit 27 according to FIG. 10, wherein the penultimate mirror M7 in the projection optical unit 28 is arranged mirrored about a plane parallel to the xz-plane in comparison with the arrangement of the penultimate mirror M8 of the projection optical unit 27. In the beam guidance of the projection optical unit 28, the chief rays 16 of the beam path cross between the mirrors M1 and M2 on the one hand and the beam path between the mirrors M5 and M6 on the other hand. The two mirrors M2 and M3 on the one hand and the two mirrors M5 and M6 on the other hand, for grazing incidence, are in each case embodied as a pair of mirrors, the deflecting effects of which add up. In the projection optical unit 28, only the last mirror M8 is embodied with a passage opening 17 for the passage of the imaging light 3 guided between the mirrors M6 and M7. In the projection optical unit 28, a z-distance of the object plane 5 from the image plane 9 is approximately 2000 mm. In the projection optical unit 28, an object/image offset is approximately 1000 mm. A further embodiment of a projection optical unit 29, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 12. Components and functions which were already explained above in the context of FIGS. 1 to 11 are appropriately denoted by the same reference signs and are not discussed again in detail. The projection optical unit 29 has a total of eight mirrors M1 to M8. The mirrors M1, M7 and M8 are embodied as mirrors for normal incidence. The mirrors M2, M3, M4, M5 and M6 are embodied as mirrors for grazing incidence. Thus, the projection optical unit 29 has five mirrors for grazing incidence arranged in succession. All mirrors for grazing incidence M2 to M6 have an adding deflecting effect on the imaging light 3 in the projection optical unit 29. After the mirror M5, the beam path in the projection optical unit 29 corresponds qualitatively to that in the projection optical unit 7 according to FIG. 2. In the projection optical unit 29, only the last mirror M8, once again, includes a passage opening 17 for the passage of the imaging light 3 guided between the mirrors M6 and M7. In the projection optical unit 29, a z-distance between the object and image planes 5, 9, parallel to one another, is approximately 2500 mm. In the projection optical unit 29, an object/image offset is approximately 3000 mm. A further embodiment of a projection optical unit 30, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIG. 13. Components and functions which were already explained above in the context of FIGS. 1 to 12 are appropriately denoted by the same reference signs and are not discussed again in detail. The projection optical unit 30 has a total of eleven mirrors M1 to M11. The mirrors M5, M10 and M11 are embodied as mirrors for normal incidence. The mirrors M1, M2, M3, M4, M6, M7, M8 and M9 are embodied as mirrors for grazing incidence. Thus, the projection optical unit 30 has two groups with in each case four mirrors for grazing incidence arranged in succession. The deflecting effects of the mirrors M1 to M4 for grazing incidence add up. The deflecting effects of the mirrors M6 to M9 for grazing incidence add up. After the mirror M8, the imaging beam path in the projection optical unit 30 corresponds qualitatively to that in the projection optical unit 28 according to FIG. 11, after the mirror M4 therein, mirrored about a plane parallel to the xz-plane. A further embodiment of a projection optical unit 31, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIGS. 14 and 15. Components and functions which were already explained above in the context of FIGS. 1 to 13 are appropriately denoted by the same reference signs and are not discussed again in detail. FIG. 14 shows a meridional section of the projection optical unit 31. FIG. 15 shows a sagittal view of the projection optical unit 31. The projection optical unit 31 has a total of 8 mirrors M1 to M8 and, in terms of the basic design thereof, it is similar to e.g. the projection optical unit 7 according to FIG. 2. The mirrors M1 to M8 are once again embodied as free-form surface mirrors, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 31 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 14/15Exemplary embodimentFIG. 14/15NA0.6Wavelength13.5nmField dimension x13.0mmField dimension y1.2mmField curvature0.0493151/mmStopS9 TABLE 2 for FIG. 14/15SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−760.703509410.00261095−690.411376630.00291701REFLM71660.51779822−0.00120425351.41973469−0.00569210REFLM622413.77181938−0.00002294—0.00038276REFLM5—0.000006946970.73341488−0.00134567REFLM4−1968.891329350.00100852−1867.994126000.00107840REFLM3−8443.924863510.00004792−8485.602253770.00116489REFLM2−2785.908856590.000177022068.91589871−0.00392049REFLM119049.58074618−0.00009999−1346.044792340.00156005REFL TABLE 3a for FIG. 14/15CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−760.70350940 1660.5177980022413.77182000C7−2.33007014e−082.88578547e−072.2753674e−07C9−1.18967539e−08−3.88069638e−07−1.7457017e−07C10−2.72776659e−111.49271555e−096.68609309e−10C12−7.0442837e−11 5.59222539e−09 −3.8203442e−10C14−2.75271127e−116.67807776e−09−5.77862714e−10C16−2.23080012e−14 1.04050752e−12−3.23543892e−12C18−4.50583763e−14−4.27223388e−128.34265088e−13C20−1.4274792e−14−1.06939915e−11−2.23351616e−12C21−7.56087206e−174.59226247e−15−3.59682046e−15C23−2.39764985e−16 3.8987218e−141.13689144e−14C25−2.30791712e−16 1.29791609e−13−6.73241398e−16C27−6.65038444e−17 1.43884373e−13−9.82855694e−15C29−2.53005387e−20 1.04942825e−17 2.27512685e−17C31−1.01909319e−19 1.61698231e−17−3.69216305e−17C33−9.10891737e−20−1.87239071e−16−9.10355957e−20C35−2.22321038e−20 −3.6078348e−16−4.66136303e−17C36−1.15852474e−22 2.8817043e−201.65439247e−19C38−6.28157898e−22 3.07592107e−19−6.87738716e−22C40−9.6788962e−22 1.31683563e−18 1.27689461e−19C42−6.41461387e−223.2410417e−18 −8.59875947e−22C44−1.5313164e−223.93814067e−18−2.18742961e−19C46−1.13873934e−251.33094976e−22−8.48120432e−22C48−2.12040282e−25−1.87148715e−228.70636092e−22C50−3.26381834e−25−2.12882905e−215.2058061e−22C52−1.88634319e−25−8.06669662e−211.43430743e−22C54−3.77802198e−26−1.65415378e−20−8.35116913e−22C55−2.78299672e−281.62987882e−25−1.26276164e−23C57−1.13733455e−273.09234722e−24−1.06004981e−23C59−2.50973358e−272.05233308e−23−1.18561349e−23C61−2.36012273e−276.71690321e−23−4.77169105e−25C63−1.07735394e−271.14300682e−222.74390777e−25C65−1.68978578e−288.85821016e−23−3.96110871e−24C671.51915362e−32−2.32859315e−278.22294799e−26C69−5.49655364e−311.39198769e−26−4.76626411e−26C71−1.02066385e−306.61474215e−26−9.93012444e−26C73−1.18308652e−304.75522732e−26−6.29472298e−26C75−5.84567673e−31−7.56976341e−26−5.49230676e−27C77−1.06877542e−316.97381799e−26−4.17957059e−26C78−6.57287449e−34−1.11031193e−305.04699814e−28C80−4.98973258e−33−3.42075816e−293.32058589e−28C82−1.47067638e−32−1.97911989e−281.10888783e−27C84−2.39766693e−32−8.4948077e−289.24713394e−29C86−2.10528972e−32−4.47266704e−28−1.36080649e−28C88−9.49212101e−333.40835449e−27−3.22056057e−29C90−1.85536567e−336.09359424e−27−3.22300574e−28C921.14904466e−374.55084533e−32−2.32548127e−30C94−3.94852331e−37−6.02019105e−322.65660093e−30C96−6.82573646e−37−1.80150194e−304.77721528e−30C983.49439171e−37−6.96859581e−304.3682388e−30C1008.37743218e−37−2.35053497e−291.52429646e−30C1024.22187524e−37−7.01661753e−29−1.0247849e−31C1041.07716944e−37−9.6147079e−29−1.20989386e−30C1057.66857985e−404.18651817e−35−8.36182433e−33C1075.95979105e−391.31671069e−33−3.54017002e−33C1092.67422787e−389.8779453e−33−4.83481101e−32C1116.45464453e−385.60289315e−32−8.16147728e−33C1138.78194876e−381.58284154e−311.4522278e−32C1156.57244583e−382.85637687e−315.61495185e−33C1172.60731766e−384.34645199e−31−2.42083693e−34C1194.80920542e−394.05075079e−31−1.74525827e−33C121−7.24465698e−4300C123−5.06090521e−4200C125−2.11201601e−4100C127−3.93520662e−4100C129−4.26707116e−4100C131−2.6866198e−4100C133−9.02589569e−4200C135−1.35713124e−4200C136−6.18315205e−4500C138−5.64222317e−4400C140−2.25923694e−4300C142−5.2742383e−4300C144−7.72344846e−4300C146−7.07223784e−4300C148−3.9358099e−4300C150−1.23782731e−4300C152−1.76195917e−4400 TABLE 3b for FIG. 14/15CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−61404.35326000−1968.89132900−8443.92486400C7−1.68207907e−07−9.69253223e−08−1.61488272e−08C9−1.68739886e−07−4.92868764e−072.12423419e−08C101.37381131e−10−4.29245796e−12−3.01016486e−11C121.73273328e−102.8015583e−10−3.01270218e−11C143.39901777e−102.62958278e−09−3.12591627e−11C16−2.02771855e−13−6.55098858e−145.94264568e−14C18−2.74086745e−13−2.19243624e−121.84091903e−14C20−1.11184944e−12−1.64987945e−112.75233054e−14C21−1.66473292e−165.11085588e−185.26119437e−17C23−1.53971529e−165.55797544e−16−6.75020173e−17C25−1.4400902e−161.63350353e−14−5.16160437e−17C272.78000528e−151.23712765e−13−3.82616113e−17C29−4.21493833e−19−8.59118066e−20 −6.89623715e−20C311.37929257e−18−5.35246837e−186.50922922e−20C337.35166575e−18−1.3798481e−165.66413099e−20C35−2.94790982e−17−8.56072868e−164.52051441e−20C36−3.95620249e−213.9780575e−23−1.10791979e−21C387.20372936e−211.07488208e−21−3.83039519e−22C40−3.66632457e−207.37896563e−20−8.63659651e−23C421.11889421e−191.33985205e−18−9.65351264e−23C44−2.23316105e−195.21035424e−18−6.41320506e−23C466.98222374e−234.14830144e−259.00262127e−25C481.89025842e−23−2.64909189e−231.42487114e−24C50−6.54336013e−22−9.0106405e−223.32110828e−25C522.37305051e−21−6.69630166e−211.54439296e−25C54−2.44135026e−21−4.36511688e−207.91478948e−26C553.57408258e−266.04631528e−294.61140016e−27C57−5.70542383e−25−2.22061343e−271.19061262e−26C592.23346131e−24−3.29453086e−25 −2.43403831e−27C61−1.08608159e−23−3.59843538e−24 −1.04602448e−27C634.01727698e−231.17803737e−22−3.01269966e−28C65−3.08466704e−231.2589272e−21−9.07944125e−29C67−9.09279986e−28−2.73791414e−30 −1.05225381e−29C691.84008908e−281.67755413e−28−3.76114547e−29C712.98171505e−267.89504238e−271.08887944e−30C73−1.45773298e−251.37144291e−259.62125603e−31C755.4755988e−25−1.75156336e−244.40838424e−31C77−6.88817386e−2501.65923732e−31C78−1.93722111e−31−6.27481076e−34−4.32487572e−32C808.17303266e−302.11008905e−32−1.14299001e−31C82−6.67999871e−29 5.2310253e−30 4.65450563e−32C842.67006152e−283.0291707e−28 8.73563385e−33C86−1.53075751e−272.20926318e−271.52319789e−33C885.16885409e−27 2.74028858e−27 −7.11278706e−34C90−8.23017746e−270−4.3534126e−34C929.28021791e−33 1.61499153e−353.4340304e−34C941.69089847e−32 −8.96493937e−343.93253353e−34C96−3.39525427e−31−7.08991192e−32−4.73501064e−35C981.66641579e−30 −3.0950904e−30 −2.05074664e−35C100−9.51326703e−30−9.26698789e−29−2.50411785e−36C1022.94059028e−2901.04321451e−36C104−4.69127888e−2906.43577491e−37C105−1.7696216e−36 4.64103982e−39 −1.04049749e−37C107−8.97432009e−352.19653265e−38 −4.82828467e−37C1095.43884259e−34 −1.60384827e−35−3.57026561e−37C111−8.8263867e−34 −2.16883676e−336.55702741e−38C1135.276912e−33−4.68627022e−326.67841412e−39C115−2.42873892e−32−1.04759785e−308.77078073e−40C1177.30432753e−320−6.91810729e−40C119−1.02386637e−310−3.62760873e−40 TABLE 3c for FIG. 14/15CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−2785.9088570019049.58075000C71.02179797e−07−1.83712276e−07C92.08877338e−07−4.58660126e−08C10−2.19824304e−10−1.67890734e−11C12−4.14802496e−104.67483698e−11C149.46958508e−10 1.1339512e−11C166.64712822e−13−2.5185941e−13C181.1708882e−13 −6.01722521e−13C202.83635538e−12−4.88209081e−14C212.7928674e−16 −2.02129522e−18C231.42351482e−15−7.27365863e−16C25−1.92431341e−154.83885181e−16C278.77128791e−15−1.97905684e−17C297.21451366e−18−1.28398658e−18C316.30102696e−189.94551948e−19C333.50555759e−181.88504443e−18C353.12699312e−171.06434779e−19C36−3.68339425e−20−2.27688495e−21C383.61485045e−20−1.70028002e−20C405.05283454e−21−1.07042666e−20C421.99680032e−211.04162271e−20C441.24570222e−19−1.55097266e−21C46−3.21749539e−225.12417577e−23C481.68890864e−22 −3.98185412e−23C501.15552342e−24 −5.91175233e−23C52−1.84254516e−23−1.14320553e−22C543.61172897e−22−6.223901e−23C552.57524069e−25 1.13131912e−25C57−1.72472199e−248.57655135e−25C592.79637731e−25 2.11373459e−24C61−2.11635905e−242.45014709e−25C63−3.38605775e−24−5.95868212e−25C65−5.51007018e−25−8.97281776e−26C671.78442615e−27 −3.12729249e−28C69−4.68488975e−271.28492955e−26C711.54333938e−26 2.09200168e−26C731.94658666e−26 1.65108524e−26C756.09850146e−27 7.04786074e−27C774.18619136e−274.5184573e−27C781.54200314e−31−1.32478619e−30C806.95048519e−30 2.51954717e−29C82−3.04720781e−29−3.83569962e−29C845.24989858e−29 −4.69742338e−30C862.04128459e−28 4.07157123e−29C882.00406824e−28 3.07404295e−29C909.4685541e−29 1.13319109e−29C923.87396229e−32 −6.19892982e−32C946.51760335e−32 −6.54903162e−31C96−2.20158879e−31−1.35223368e−30C98−3.33335228e−31−1.59978619e−30C100−1.8982851e−31 −9.29567239e−31C1022.55028572e−32 −2.74472497e−31C1049.15729393e−32 −1.39144572e−31C1051.54616461e−35 −4.43620458e−35C1072.57448706e−34 −2.24105011e−33C1094.15070906e−34 −4.2791598e−33C111−4.57189383e−34−5.88226204e−33C113−2.7712617e−33 −7.99527615e−33C115−5.61503186e−33−4.25467966e−33C117−3.62496099e−33−1.32244101e−33C119−9.3965259e−34 −5.41759129e−34 TABLE 4a for FIG. 14/15SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000001.58228046644.46684396M70.00000000 −130.9432089386.28913162M6−0.0000000079.003895881146.86693841M5−0.00000000315.048396181400.80720652M4−0.00000000708.317557831568.71377057M3−0.00000000−353.767951801371.20626759M2−0.00000000−1004.08161985938.25663352Stop−0.00000000−1059.88207749829.40621334M1−0.00000000 −1419.83403251171.07007671Object plane−0.00000000−1596.598321231556.09991381 TABLE 4b for FIG. 14/15SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M8−6.876970880.00000000−0.00000000M7167.056544940.00000000−0.00000000M663.67723779−0.000000000.00000000M537.03218867−0.00000000−0.00000000M4−72.572923410.00000000−0.00000000M321.99697785−0.00000000 −0.00000000M247.89820238−0.000000000.00000000Stop33.48047202−0.00000000180.00000000M1169.482626710.00000000−0.00000000Object plane1.44970929−0.000000000.00000000 TABLE 5 for FIG. 14/15SurfaceAngle of incidence [deg]ReflectivityM86.744732670.66088293M71.021186530.66560218M675.103089950.80563416M577.689316280.84631558M46.864107760.66070326M378.326679650.85548939M275.725136850.81598083M117.744440120.62654454Overall transmission0.0867 TABLE 6 for FIG. 14/15X[mm]Y[mm]Z[mm]−0.0000000088.442589730.0000000024.6469911287.075995810.0000000048.8437495083.041257970.0000000072.1343306976.527353580.0000000094.0534420667.829417680.00000000114.1265653857.321955810.00000000131.8750971545.427464390.00000000146.8270762832.585297600.00000000158.5333196119.225135870.00000000166.588102895.748167520.00000000170.65260767−7.483261590.00000000170.47874487−20.149848750.00000000165.93088822−31.977200960.00000000157.00305460−42.737621900.00000000143.82941376−52.252071200.00000000126.68708163−60.391196250.00000000105.99130912−67.073834130.0000000082.28375334−72.261733000.0000000056.21483844−75.949585830.0000000028.52131067−78.150899810.000000000.00000000−78.882294780.00000000−28.52131067−78.150899810.00000000−56.21483844−75.949585830.00000000−82.28375334−72.261733000.00000000−105.99130912−67.073834130.00000000−126.68708163−60.391196250.00000000−143.82941376−52.252071200.00000000−157.00305460−42.737621900.00000000−165.93088822−31.977200960.00000000−170.47874487−20.149848750.00000000−170.65260767−7.483261590.00000000−166.588102895.748167520.00000000−158.5333196119.225135870.00000000−146.8270762832.585297600.00000000−131.8750971545.427464390.00000000−114.1265653857.321955810.00000000−94.0534420667.829417680.00000000−72.1343306976.527353580.00000000−48.8437495083.041257970.00000000−24.6469911287.075995810.00000000 An overall reflectivity of the projection optical unit 31 is 8.67%. The projection optical unit 31 has an image-side numerical aperture of 0.6. The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1.20 mm. The image field 8 is curved symmetrically with respect to the y-axis with a radius of curvature of e.g. 20.28 mm. Thus, the projection optical unit 31 has arced fields and no rectangular fields. The projection optical unit 31 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The projection optical unit 31 has exactly eight mirrors M1 to M8. The mirrors M2 and M3 on the one hand, and M5, M6 on the other hand are embodied as mirrors for grazing incidence and are arranged in each case as a mirror pair directly behind one another in the imaging beam path. The projection optical unit 31 has exactly four mirrors for grazing incidence, namely the mirrors M2, M3, M5 and M6. The mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence. In the projection optical unit 31, a stop 18 is arranged in the beam path between the mirrors M1 and M2, near the grazing incidence on the mirror M2. Alternatively or additionally, a stop can be arranged directly on the surface of the mirror M2. The projection optical unit 31 has a reducing imaging scale β=8.00. An angle of incidence of the chief rays 16 in the object plane 5 is 6.3°. In the meridional section according to FIG. 14, the chief rays extend between the object field 4 and the mirror M1 in a divergent manner. In the yz-plane, an entrance pupil of the projection optical unit 31 lies −3500 mm in front of the object field 4 in the beam path of the illumination light. In the xz-plane (cf. FIG. 15), the entrance pupil lies 2100 mm after the object field in the imaging beam path of the projection optical unit 31. In the xz-section (cf. FIG. 15), the stop 18 can lie at a position displaced in the z-direction compared to its position in the yz-section. A z-distance between the object field 4 and the image field 8 is approximately 1600 mm. An object/image offset (dOIS) is approximately 1560 mm. A free working distance between the mirror M7 and the image field 8 is 61 mm. In the projection optical unit 31, a scanned RMS value for the wavefront aberration is at most 8 mλ and, on average, 7 mλ. A maximum distortion value is at most 0.12 nm in the x-direction and at most 0.08 nm in the y-direction. A telecentricity value in the x-direction is at most 0.61 mrad on the image field-side and a telecentricity value in the y-direction is at most 1.16 mrad on the image field-side. Further mirror data emerge from the following table. TABLE 7 for FIG. 14/15M1M2M3M4M5M6M7M8Maximum angle of incidence [deg]18.478.279.310.882.378.918.87.3Mirror extent (x) [mm]245.4366.0506.8606.2426.9218.7323.2804.5Mirror extent (y) [mm]246.9252.0795.884.5175.8270.5173.3788.5Maximum mirror diameter [mm]252.6366.3803.8606.2426.9281.1323.4805.8 There is an intermediate image 19 in the beam path in the region of a reflection on the mirror M5 in the yz-plane (FIG. 14) and in the imaging beam path region between the mirrors M6 and M7 in the xz-plane (FIG. 15). The mirror M8 is obscured and includes a passage opening 17 for the passage of the illumination light 3 in the imaging beam path between the mirrors M6 and M7. Only the last mirror M8 in the imaging beam path includes a passage opening 17 for the imaging light 3. All other mirrors M1 to M7 have a continuous reflection surface. The reflection surface of the mirror M8 is used around the passage opening 17 thereof. The mirrors M1, M3, M4, M6 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The other mirrors M2, M5 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 for grazing incidence have very large radii and only constitute small deviations from plane reflection surfaces. FIG. 15A shows edge contours of the surfaces on the mirrors M1 to M8 of the projection optical unit 31 which are in each case impinged upon by illumination light 3, i.e. the so-called footprints of the mirrors M1 to M8. These edge contours are in each case depicted in an x/y-diagram which corresponds to the local x- and y-coordinates of the respective mirror M1 to M8. The illustrations are true to scale in millimeters. The mirrors M1, M2, M6 and M8 have an x/y-aspect ratio which does not deviate, or only deviates slightly, from the value 1. The mirror M3 has an x/y-aspect ratio of approximately 0.55. The mirror M4 has an x/y-aspect ratio of approximately 7.5. The mirror M5 has an x/y-aspect ratio of approximately 2.5. The mirror M7 has an x/y-aspect ratio of approximately 2. A further embodiment of a projection optical unit 32, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIGS. 16 and 17. Components and functions which were already explained above in the context of FIGS. 1 to 15 are appropriately denoted by the same reference signs and are not discussed again in detail. FIG. 16 shows a meridional section of the projection optical unit 32. FIG. 17 shows a sagittal view of the projection optical unit 32. The projection optical unit 32 has a total of 8 mirrors M1 to M8 and, in terms of the basic design thereof, it is similar to e.g. the projection optical unit 7 according to FIG. 2. The mirrors M1 to M8 are once again embodied as free-form surface mirrors, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 32 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 16/17Exemplary embodimentFIG. 16/17NA0.63Wavelength13.5nmField dimension x13.0mmField dimension y1.2mmField curvature0.01/mmStopS9 TABLE 2 for FIG. 16/17SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−931.708408710.00212869−869.276047630.00232012REFLM72483.73117622−0.00080462590.74829460−0.00338815REFLM64073.92459627−0.0000923018265.52467135−0.00058241REFLM57333.37887582−0.000064392756.23195835−0.00307339REFLM4−2343.608286830.00084551−1275.307077220.00158285REFLM3−8176.836660050.00004510−22705.819652490.00047771REFLM2−2347.824209770.000149565323.37610244−0.00213994REFLM17536.03761813−0.00025355−1766.436139190.00118510REFL TABLE 3a for FIG. 16/17CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−931.70840870 2483.73117600 4073.92459600C7−2.91071984e−081.03086086e−081.42663812e−08C9−1.4873513e−08 −2.95346773e−07−1.46095442e−08C10−1.35088934e−117.46509583e−10 1.66564805e−10C12−3.04656958e−111.97488711e−09 4.76376807e−11C14−1.4685502e−111.96447383e−09 −6.83009219e−11C16−2.0880499e−14−2.54564229e−13−4.64702132e−13C18−3.50367731e−14−1.15902664e−124.62582078e−14C20−1.30121192e−14−2.52789708e−12−2.03948925e−13C21−2.58185385e−17 1.1522247e−15 −2.7157107e−17C23−7.74145665e−177.55596284e−159.77435168e−16C25−7.78695864e−171.95378488e−14 2.0332385e−16C27−2.47396927e−171.84775168e−14−6.22309514e−16C29−1.76814258e−202.09437366e−18−1.49864939e−19C31−5.60530841e−205.96908377e−19−9.33357714e−19C33−4.97811363e−20−2.08627141e−173.07259452e−19C35−1.3997665e−20−3.46362367e−17−1.96498619e−18C36−3.36480331e−23 5.9536477e−21 −5.41486656e−21C38−1.43652378e−223.57217041e−20−2.3879585e−21C40−2.19649946e−221.05418252e−191.2923996e−21C42−1.50444552e−222.35618312e−19 −1.0808335e−21C44−3.74578417e−231.91215151e−19 −6.45753285e−21C46−3.13089528e−26−3.39340782e−23−3.83895365e−23C48−7.18534794e−26−6.31648018e−23−1.051438e−22C50−1.09073223e−25−3.26404881e−22−2.85984644e−23C52−6.83064745e−26−9.21698689e−22−1.08466535e−23C54−1.42936475e−26−6.02090954e−22−2.26713596e−23C55−1.98418542e−29−2.78722687e−261.37273683e−25C57−1.18366952e−284.63896896e−264.78797534e−25C59−2.85319764e−288.94639444e−25 2.0872644e−25C61−2.84788816e−282.79795669e−244.69038748e−27C63−1.29159985e−283.56080821e−24−5.79635406e−28C65−2.10189947e−29 2.1127208e−24 −8.21926722e−26C67−2.32273683e−32 4.1958734e−283.52289657e−27C69−2.40813769e−316.21640783e−28 6.54476369e−27C71−4.32683743e−315.44469541e−271.39064733e−27C73−4.15492269e−311.39187594e−263.08809486e−28C75−1.90762176e−312.23223868e−262.68993428e−28C77−3.53653344e−326.58181727e−27−2.56565757e−28C78−1.28401944e−344.22239739e−31 −5.6263208e−30C80−8.00611222e−34 1.4969115e−30 −3.65636379e−29C82−2.08044469e−339.27586881e−31−2.82097568e−29C84−2.99812506e−33−2.81205697e−29 1.23362854e−30C86−2.44765003e−33−5.59224504e−29 3.32486225e−31C88−1.08671322e−33−1.78093061e−29 1.1699384e−30C90−2.11573397e−34 5.14032892e−29−5.63928364e−31C923.23220481e−38−2.38769667e−33−5.74687656e−32C943.21925323e−37−3.11471422e−33−1.32786862e−31C967.57126123e−37−6.66791486e−32−4.22660394e−32C989.69365768e−37−2.934094e−319.32991054e−34C1007.04923179e−37−6.52696174e−31−6.22093735e−33C1022.62042917e−37−1.04820586e−30 2.08603643e−33C1044.07988929e−38−7.5774402e−31−7.31578585e−34C1051.66061587e−40−4.99206036e−37 8.05574038e−35C1071.25271974e−395.59249922e−366.75124517e−34C1094.10714369e−39 6.2048029e−35 7.7682584e−34C1117.47611007e−396.35194423e−34−4.50825615e−36C1138.28548592e−392.16520675e−33−3.39262679e−35C1155.5390038e−393.67754227e−33−1.22938875e−35C1172.08161823e−394.05364531e−331.44193642e−36C1193.61466995e−402.14759918e−33−4.15418675e−37C121−1.7470143e−4300C123−1.24194664e−4200C125−3.89205838e−4200C127−6.57194445e−4200C129−6.52993268e−4200C131−3.87022353e−4200C133−1.24875231e−4200C135−1.70148907e−4300C136−3.91176552e−4600C138−3.37053804e−4500C140−1.30298939e−4400C142−2.82508364e−4400C144−3.81978621e−4400C146−3.31582016e−4400C148−1.79377138e−4400C150−5.55598461e−4500C152−7.76672874e−4600 TABLE 3b for FIG. 16/17CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX7333.37887600 −2343.60828700−8176.83666000C7−8.06007218e−08−3.48950166e−084.05927788e−09C9−2.08509486e−078.94289204e−081.77611145e−08C104.87512053e−11−3.68853182e−12−2.10548784e−12C126.98533228e−11−1.68926357e−12−1.81838078e−11C147.56830797e−10−7.16019789e−10−1.28620718e−11C16−4.21056731e−14−9.71341862e−151.51233551e−14C182.16257556e−13 1.0109964e−132.12796111e−14C20−2.45524747e−122.43722256e−121.97634161e−14C21−1.00355924e−161.46336047e−18−3.64595782e−17C23−8.60207099e−17−7.86037179e−18−1.04353271e−17C25−1.04377426e−15−4.99679238e−16−4.48160081e−17C279.80765672e−15−7.9361522e−15 −2.3137161e−17C295.00768352e−20−1.44519643e−20−1.3579059e−21C31−4.94223102e−193.37633547e−205.80350123e−20C337.13421062e−188.97303449e−19 6.79018066e−20C35−4.57055281e−17−2.14705684e−163.32978205e−20C366.29537322e−22−5.41983346e−242.94852673e−22C384.56244955e−218.73176771e−25 2.28099588e−23C40−5.65666291e−22−4.49558052e−21−7.30396947e−23C42−1.97093015e−20−5.08595618e−19−7.04354696e−23C442.25870745e−19−1.86162624e−18−6.57401088e−23C46−4.76975597e−253.18692569e−26 −5.31469542e−25C48−2.62153771e−237.33616878e−26 −1.56666314e−25C50−8.35149543e−23−3.1998671e−221.17242589e−25C522.06972807e−221.67741969e−22 4.56588177e−25C54−8.42020489e−221.29228647e−19 1.50592072e−25C55−8.54723421e−273.09703897e−29−2.51969622e−27C57−2.15095808e−26−1.45976138e−271.12593984e−27C592.73391474e−25−7.44808008e−26−6.80649268e−28C615.18559089e−253.81005555e−24−3.08355376e−27C63−2.47889841e−243.09020753e−22 −1.76838539e−27C655.34614791e−251.92266397e−21 −1.90865204e−29C67−2.25910931e−30−4.54679793e−314.05531645e−30C691.74490344e−28−3.06527261e−295.09507467e−30C71−9.47792011e−283.40412751e−27 1.35919614e−29C73−1.28041726e−272.17008338e−25 1.12809097e−29C751.16717661e−265.05227073e−241.33613049e−31C772.41916614e−261.23707257e−24 2.90705483e−31C784.99191675e−32−2.63305732e−35 6.4801327e−33C802.40587164e−315.98530383e−33−2.08464487e−32C82−1.49661977e−309.35640119e−31−4.42072324e−32C84−5.16969383e−307.40737374e−29 −3.85234173e−32C862.80547586e−292.36087579e−27−8.47384767e−34C88−5.66097673e−293.80301606e−261.2873158e−33C90−1.65077574e−28−1.84363909e−25−2.11409931e−33C92−9.95571829e−351.28242738e−36 −2.84775083e−36C94−2.55937997e−333.19723428e−346.69265283e−35C961.72531216e−321.04943712e−32 9.69063033e−35C981.30347826e−323.93847703e−315.84595971e−36C100−1.82235259e−311.39933265e−29 −2.43085728e−35C1023.33993384e−31 1.0462556e−28 1.45322044e−35C1043.61923001e−31−1.37953609e−272.87194159e−37C105−9.27081346e−38−3.28332618e−41−3.88255253e−39C1075.90554811e−371.77805509e−38 −1.21407691e−39C1095.75559924e−36 1.9649268e−36 −7.40697936e−38C111−6.21170396e−35−1.27239557e−35−7.22725357e−38C1131.18750818e−341.69960241e−338.51832143e−38C115 1.0492163e−342.21579419e−32−3.56423101e−38C117−4.95984269e−346.99631983e−321.79158311e−39C119−2.2869355e−34−3.11861224e−30−3.49739868e−40 TABLE 3c for FIG. 16/17CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−2347.824210007536.03761800C7−7.03485497e−08−1.86250955e−07C99.59401595e−09−5.82539372e−08C10−8.37768666e−11−2.02011333e−11C12−2.254116e−105.08465307e−11C141.12290556e−11−1.50961208e−11C161.29016905e−13−1.19111437e−13C181.01010377e−13−2.20807707e−13C20 5.5795716e−14 −4.18443714e−14C21−8.62874665e−171.04483703e−16C23−2.60494693e−164.60051315e−17C25−4.92392033e−17 −1.435823e−16C271.25996639e−16−6.05169215e−18C296.11488553e−197.87050699e−19C314.24373257e−191.12622911e−19C332.22031302e−192.89213141e−19C351.26284752e−192.81920022e−19C36−1.33244714e−21−1.46603103e−21C38−6.52230969e−22−6.37096287e−21C40−1.36827685e−21−1.09951069e−21C42−1.19387383e−21−2.71718561e−21C444.6650984e−238.53547123e−23C46−9.78213588e−24−3.184402e−23C482.1349715e−24 −4.73107403e−23C502.30513651e−24−8.85417497e−23C52−1.30422404e−24−2.08672516e−23C542.56099182e−24−1.11997994e−23C55−2.01832009e−276.22382668e−26C57−2.09810378e−263.74797998e−25C594.07233629e−29 5.10816825e−26C61 3.6325349e−26 −9.00558717e−26C631.56403725e−26 1.07987651e−25C658.21661731e−27 5.68528189e−26C677.63814345e−29 7.63520422e−28C695.02221412e−30 1.3232798e−27C711.77729214e−29 5.33156044e−27C732.79158365e−294.63514451e−27C752.53015945e−291.30513775e−27C771.4759564e−29 3.5264471e−28C783.46417745e−32−5.78316004e−31C801.45159699e−31−1.10067449e−29C82 9.0694834e−32−1.42216857e−31C84−6.89700486e−311.16109131e−29C86−7.49364228e−311.17727865e−29C88−1.7339254e−31 −2.80482217e−30C90−4.47739797e−32−2.81074177e−30C92−1.81662263e−34−6.13529779e−33C941.28959854e−34−4.08542518e−33C964.86782417e−35−7.56607259e−32C984.67335248e−35−1.27523429e−31C100 6.049461e−34−8.28428683e−32C1021.19416219e−34 −1.88207341e−32C1042.22522278e−34 −5.85049322e−33C105−1.53243521e−37−5.49967483e−36C107−6.52477544e−371.45163725e−34C109−1.61717488e−368.41098542e−36C111 3.3725318e−36−2.0054224e−34C1138.27472276e−36−4.23023623e−34C1156.99221137e−36−2.55382174e−34C1171.36584295e−362.10184113e−36C1195.55470158e−373.89090885e−35 TABLE 4a for FIG. 16/17SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.00000000784.93663307M70.00000000−179.68746470105.44220179M60.0000000055.204384851396.55879809M50.00000000268.650637531738.35972839M40.00000000722.064962952007.61241376M3−0.00000000−674.419462241630.11468301M2−0.00000000−1315.579392991157.79929585Stop−0.00000000−1561.97639547784.10794177M1−0.00000000−1988.27617201137.57190792Object plane−0.00000000−2017.390232291874.54221542 TABLE 4b for FIG. 16/17SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M8−7.406198440.00000000−0.00000000M7167.43829886−0.00000000−0.00000000M668.852616590.00000000−0.00000000M544.359752350.00000000−0.00000000M4−67.085034470.00000000−0.00000000M325.75208383−0.00000000−0.00000000M246.48912783−0.000000000.00000000Stop−33.39924707180.000000000.00000000M1163.780510350.00000000−0.00000000Object plane−5.37252548−0.000000000.00000000 TABLE 5 for FIG. 16/17SurfaceAngle of incidence [deg]ReflectivityM87.406198440.65984327M72.250695740.66521806M679.163621990.86711124M576.343513770.82589579M47.788300580.65919310M379.374581110.86997104M279.888374900.87682901M117.179757420.62938643Overall transmission0.0995 TABLE 6 for FIG. 16/17X[mm]Y[mm]Z[mm]0.00000000−64.681915620.0000000033.53875145−63.833590710.0000000066.38499140−61.303817590.0000000097.85010336−57.138472100.00000000127.25390981−51.414870550.00000000153.93066205−44.242930630.00000000177.23821823−35.766601750.00000000196.57137775−26.165523950.00000000211.37968084−15.656547630.00000000221.18976357−4.493385960.00000000225.630640827.038031490.00000000224.4592069518.628721130.00000000217.5826145129.960136970.00000000205.0744197140.720108100.00000000187.1821157050.618688990.00000000164.3245005859.401033680.00000000137.0789767066.855260380.00000000106.1604470372.815047830.0000000072.3946270077.156962910.0000000036.6884028479.795825330.000000000.0000000080.681071040.00000000−36.6884028479.795825330.00000000−72.3946270077.156962910.00000000−106.1604470372.815047830.00000000−137.0789767066.855260380.00000000−164.3245005859.401033680.00000000−187.1821157050.618688990.00000000−205.0744197140.720108100.00000000−217.5826145129.960136970.00000000−224.4592069518.628721130.00000000−225.630640827.038031490.00000000−221.18976357−4.493385960.00000000−211.37968084−15.656547630.00000000−196.57137775−26.165523950.00000000−177.23821823−35.766601750.00000000−153.93066205−44.242930630.00000000−127.25390981−51.414870550.00000000−97.85010336−57.138472100.00000000−66.38499140−61.303817590.00000000−33.53875145−63.833590710.00000000 An overall reflectivity of the projection optical unit 32 is 9.95%. The projection optical unit 32 has an image-side numerical aperture of 0.63. The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1.20 mm. The projection optical unit 32 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The projection optical unit 32 has exactly eight mirrors M1 to M8. The mirrors M2 and M3 on the one hand, and M5, M6 on the other hand are embodied as mirrors for grazing incidence and are arranged in each case as a mirror pair directly behind one another in the imaging beam path. The projection optical unit 32 has exactly four mirrors for grazing incidence, namely the mirrors M2, M3, M5 and M6. The mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence. In the projection optical unit 32, a stop 18 is arranged in the beam path between the mirrors M1 and M2, near the grazing incidence on the mirror M2. Alternatively or additionally, a stop can be arranged directly on the surface of the mirror M2. The projection optical unit 32 has a reducing imaging scale β=8.00. An angle of incidence of the chief rays 16 in the object plane 5 is 6.3°. In the projection optical unit 32, the entrance pupil lies downstream of the object field 4 in the imaging beam path, both in the xz-plane and in the yz-plane. An extent of the chief rays 16 emanating from the object field 4 is therefore convergent both in the meridional section according to FIG. 16 and in the view according to FIG. 17. In the xz-section (cf. FIG. 17), the stop 18 can lie at a position displaced in the z-direction compared to its position in the yz-section. A z-distance between the object field 4 and the image field 8 is approximately 1680 mm. An object/image offset (dOIS) is approximately 2180 mm. A free working distance between the mirror M7 and the image field 8 is 66 mm. In the projection optical unit 32, a scanned RMS value for the wavefront aberration is at most 10 mλ and, on average, 10 mλ. A maximum distortion value is at most 0.05 nm in the x-direction and at most 0.05 nm in the y-direction. A telecentricity value in the x-direction is at most 0.56 mrad on the image field-side and a telecentricity value in the y-direction is at most 0.90 mrad on the image field-side. Further mirror data emerge from the following table. TABLE 7 for FIG. 16M1M2M3M4M5M6M7M8Maximum angle of incidence [deg]17.783.280.69.679.683.620.19.0Mirror extent (x) [mm]303.5566.4758.8892.8684.3320.4428.81036.2Mirror extent (y) [mm]297.5442.9668.0123.3268.7464.1277.51030.7Maximum mirror diameter [mm]307.4566.5882.6892.8684.4465.6429.01042.4 There is an intermediate image 19 in the beam path in the region of a reflection on the mirror M5 in the yz-plane (FIG. 16) and in the imaging beam path region between the mirrors M6 and M7 in the xz-plane (FIG. 17). The mirror M8 is obscured and includes a passage opening 17 for the passage of the illumination light 3 in the imaging beam path between the mirrors M6 and M7. Only the last mirror M8 in the imaging beam path includes a passage opening 17 for the imaging light 3. All other mirrors M1 to M7 have a continuous reflection surface. The reflection surface of the mirror M8 is used around the passage opening 17 thereof. The mirrors M1, M3, M4 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The other mirrors M2, M5, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 for grazing incidence have very large radii and only constitute small deviations from plane reflection surfaces. A further embodiment of a projection optical unit 33, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIGS. 18 and 19. Components and functions which were already explained above in the context of FIGS. 1 to 17 are appropriately denoted by the same reference signs and are not discussed again in detail. FIG. 18 shows a meridional section of the projection optical unit 33. FIG. 19 shows a sagittal view of the projection optical unit 33. The projection optical unit 33 has a total of 8 mirrors M1 to M8 and, in terms of the basic design thereof, it is similar to e.g. the projection optical unit 7 according to FIG. 2. The mirrors M1 to M8 are once again embodied as free-form surface mirrors, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 33 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 18/19Exemplary embodimentFIG. 18/19NA0.55Wavelength13.5nmField dimension x13.0mmField dimension y1.2mmField curvature0.01/mmStopS9 TABLE 2 for FIG. 18/19SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−670.357972320.00296240−627.584353290.00320950REFLM71745.55712015−0.00114571412.50033390−0.00484870REFLM64421.01009198−0.000089317185.41512590−0.00140985REFLM515855.02373559−0.000027964171.22179090−0.00216291REFLM4−1741.787258610.00114424−1057.575546860.00189775REFLM3−9485.627543320.00002417—0.00014374REFLM2−2182.911435970.000194225519.10498181−0.00170943REFLM115030.83113395−0.00012472−1265.497780660.00168608REFL TABLE 3a for FIG. 18/19CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−670.357972301745.55712000 4421.01009200C7−4.81288458e−08−3.55811479e−081.10191288e−07C9−1.43025013e−08−2.65021944e−086.09862305e−08C10−2.9090628e−112.00521492e−09 4.47450933e−10C12−7.81857726e−115.80590938e−09 −4.87603276e−12C14−4.02236114e−114.94771956e−091.0068161e−10C16−7.43164532e−14−1.95204523e−12−2.12453013e−12C18−8.64425143e−14−5.06245222e−127.37281997e−13C20−1.71739056e−14−1.20800077e−133.37980344e−13C21−1.1968188e−164.87171182e−15−1.08375275e−15C23−3.75329564e−164.39287253e−148.747056e−15C25−3.8109341e−161.16541403e−132.36512505e−15C27−1.19138037e−166.70791361e−14 1.37590246e−15C29−1.04340624e−19 2.0215171e−17 5.61602094e−18C31−2.79317699e−194.75537085e−17−1.60443831e−17C33−1.86065365e−19−1.1064442e−161.42151097e−17C35−2.70598188e−20−1.50020521e−176.37515084e−18C36−2.60850039e−225.08968358e−20−2.32816563e−20C38−1.30441247e−21 4.6799942e−19 −4.47727577e−20C40−1.96796788e−211.10597229e−185.12611591e−20C42−1.2977623e−211.89364881e−18 7.02851213e−20C44−3.09054832e−229.05751028e−19 2.94917341e−20C46−3.15590698e−25−2.08971584e−221.62115204e−22C48−6.69894425e−25 1.9553723e−22−2.33180972e−22C50−9.10706455e−259.99600993e−22−1.77260159e−22C52−4.09789778e−258.73317101e−223.10774876e−22C54−5.39704308e−26 1.78769324e−211.12292429e−22C55−6.93874331e−28−5.67024671e−269.56176548e−25C57−3.23605914e−272.18766705e−26 3.05575248e−24C59−7.20445617e−276.74742059e−24 4.95411355e−24C61−7.31071717e−27 1.7636561e−238.45206669e−25C63−3.76538565e−274.45369389e−23 7.568151e−25C65−8.10033369e−284.74178513e−232.96782466e−25C67−3.52005901e−313.12504796e−273.10279996e−27C69−2.88238592e−30−1.30629101e−272.16886937e−26C71−4.82651049e−30−6.24964383e−266.07431187e−27C73−3.68260801e−30−4.92689158e−26−2.84115615e−27C75−1.0653794e−30 −5.7005461e−26 7.30804157e−28C775.47094621e−32−8.75138214e−26 4.6058713e−28C78−2.14791056e−339.06722616e−30 −1.033614e−29C80−1.60510489e−321.35117848e−28−1.70589275e−28C82−3.93788896e−325.55787384e−28−2.81428982e−28C84−5.49581485e−321.47508315e−27−1.13602715e−28C86−4.35705736e−321.78392254e−27−4.04142212e−30C88−1.75652936e−32 7.3734889e−28 9.12651931e−32C90−2.46762348e−33−8.31242313e−283.00200174e−31C92−3.88333351e−3700C94−2.23671833e−3700C96−2.43165031e−3600C98−2.13457216e−3600C100−9.67295232e−3700C102−1.1876732e−3600C104−1.14382449e−3600C1051.53654914e−3900C1071.69206394e−3800C1093.52182989e−3800C1116.26135172e−3800C1138.30656407e−3800C1156.21596876e−3800C1171.77571315e−3800C119−5.25174568e−4000C121−7.01031193e−4200C123−4.46476068e−4100C125−1.30369062e−4000C127−2.05416782e−4000C129−1.82756747e−4000C131−8.61446766e−4100C133−1.58867275e−4100C1351.58701316e−4200C136−3.01497099e−4400C138−2.83753936e−4300C140−1.00487157e−4200C142−2.10202761e−4200C144−2.8129687e−4200C146 −2.44024498e−4200C148 −1.28745661e−42 00C150 −3.62092429e−43 00C152 −3.68635908e−4400 TABLE 3b for FIG. 18/19CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX15855.02374000−1741.78725900 −9485.62754300C7−1.31721076e−07−4.59832284e−083.52848287e−09C9−6.83242366e−081.26772922e−076.00270333e−09C101.86511896e−10−6.7240665e−12−3.86514933e−11C121.02645567e−101.40642009e−11−1.04260025e−11C143.25328748e−10−1.44116181e−09 −1.39250403e−12C161.15440436e−131.54655389e−14 1.41839307e−13C189.78984308e−14 4.72881604e−14 −7.16656945e−15C20−4.13371452e−13 6.75771744e−125.02664635e−15C21−9.27197923e−16 1.22282675e−17 −3.31198094e−16C23−1.09172383e−15−1.54608007e−16 −5.35714413e−19C25−3.20953448e−15 −1.0400161e−15 −1.84536642e−17C275.96725454e−16−4.25077515e−146.21451944e−19C292.62826512e−18−1.61888596e−201.34420461e−20C315.55652996e−181.56291853e−18 1.40973329e−19C33 2.7740609e−172.95936057e−18 −4.11709921e−20C354.55586057e−18−1.37954952e−152.58219786e−20C36−2.54645948e−21 4.64220138e−23−1.02171124e−21C382.59467077e−212.40346499e−22 1.13743233e−22C40−2.63246351e−202.2463419e−202.11256444e−22C42−1.44139765e−192.97984423e−19−1.29143298e−22C44−1.47693917e−20−9.36301568e−173.98789946e−23C463.92320225e−23−1.29229238e−253.09631337e−25C486.16075361e−232.86131689e−24−8.082018e−25C50−1.29691393e−224.15685135e−222.98588259e−25C526.01647413e−22 2.59285728e−20 −1.63194404e−25C54−2.80843932e−22−2.64870198e−18 −5.22760512e−25C55−1.90991039e−267.33311088e−29 −2.91457225e−28C57−4.94174349e−25−3.38477536e−27−6.65349621e−28C59−2.34601421e−25−6.27781517e−256.27762913e−27C611.83858604e−24 1.36415701e−23 −3.36674024e−27C63−2.23642007e−243.28284286e−22 5.96549035e−27C653.66468868e−24−4.01324036e−20−1.49374281e−27C672.66992017e−28−5.84759414e−317.70928561e−30C692.07117026e−27−1.72399089e−28 −1.27896735e−29C71−3.5305907e−28−5.73139683e−27−8.13201754e−30C73−7.57480134e−27 1.35355592e−25−2.66054764e−29C756.95016816e−27 1.92585784e−241.80471214e−29C77−1.70051404e−26−3.11308211e−229.00721038e−31C784.16730333e−324.62818363e−356.62810428e−33C80−1.17092721e−30−1.17159673e−32−1.00672006e−32C82−1.53899025e−304.95758204e−32−2.55215318e−32C84−3.41614885e−31−6.16523277e−29 1.34231774e−31C861.41066094e−291.05235757e−27−6.94396951e−32C88−1.32369475e−29−2.78941647e−27−9.85278164e−33C902.98460269e−29−9.71953419e−252.65172705e−33 TABLE 3c for FIG. 18/19CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−2182.9114360015030.83113000C74.52959985e−08−2.95215933e−07C9 7.3997303e−09 −1.06249503e−07C10−3.37134993e−10−1.38418241e−11C12−4.37041985e−10−2.98703844e−11C14−4.88477799e−12−3.88213158e−11C168.58895599e−13−6.42604386e−13C186.73225729e−13−1.25787194e−12C207.54302364e−14−1.92589494e−13C21−3.21076173e−165.29527426e−16C23−1.19828167e−15−2.79446453e−16C25−8.61713642e−16−1.12508948e−15C27−9.46017861e−17−3.35422436e−16C296.17495108e−187.41744768e−19C316.43677926e−18−5.12492497e−19C333.08530058e−18−2.24552982e−18C356.92654359e−205.26633314e−20C36−1.39923821e−20−3.80030801e−21C38−1.75236161e−20−3.41743066e−21C40−2.44288564e−203.36222578e−21C42−7.5084993e−211.13386246e−20C443.60382311e−22−1.57547758e−21C468.49074446e−247.10295318e−23C481.29274185e−221.77073952e−22C501.21275303e−225.45121326e−23C522.7448388e−23 −1.80762516e−23C54−2.99667085e−24−2.67701771e−23C558.3997029e−262.48012197e−25C57−6.89387465e−269.08010504e−25C59−1.69030389e−25−1.40396358e−24C61−1.63503627e−25−1.98765714e−24C63−4.50856916e−266.60490918e−25C65−2.69350712e−265.05364735e−25C671.81339959e−28−2.43315212e−27C69−1.13047878e−27−8.88349423e−27C71−2.086832e−27 −1.73693921e−26C73−9.67392348e−28−1.34931036e−26C75−7.15331766e−318.58630418e−27C772.26098895e−297.80811576e−27C78−2.38436227e−31−6.67264596e−30C801.8322377e−30−4.06002422e−29C826.0376388e−30 −4.8867685e−29C846.31126749e−30−4.62454207e−29C862.03909262e−30−2.42505377e−29C883.81494935e−313.31286928e−29C90−7.68322344e−332.3776391e−29 TABLE 4a for FIG. 18/19SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.00000000−1.30183991570.42723037M70.00000000−120.3488107175.51681848M60.0000000080.00209606956.51104535M50.00000000221.259256691160.16077268M40.00000000611.932581571362.59488679M30.00000000−309.467269131055.74659104M20.00000000−912.91463513655.60876883Stop0.00000000−1017.01458447474.86644530M10.00000000−1353.1507866618.46126376Object plane0.00000000−1490.556258771255.06787017 TABLE 4b for FIG. 18/19SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M8−6.694970010.00000000−0.00000000M7166.969379290.00000000−0.00000000M666.234537520.00000000−0.00000000M541.496420280.00000000−0.00000000M4−66.770542720.00000000−0.00000000M326.080775910.00000000−0.00000000M244.382779500.00000000−0.00000000Stop12.993071490.00000000−0.00000000M1165.885738940.00000000−0.00000000Object plane1.477945500.00000000−0.00000000 TABLE 5 for FIG. 18/19SurfaceAngle of incidence [deg]ReflectivityM86.814657490.66077811M70.546491700.66565825M678.613512410.85952413M577.192235050.83894755M44.790281390.66334071M383.417858100.92088922M277.761170320.84736477M120.392821000.61112963Overall transmission0.1003 TABLE 6 for FIG. 18/19X[mm]Y[mm]Z[mm]0.00000000−74.744289640.00000000−21.97577930−73.711577460.00000000−43.54745003−70.645848120.00000000−64.30774000−65.642236650.00000000−83.84419262−58.852736240.00000000−101.73934320−50.477894910.00000000−117.57413522−40.757912260.00000000−130.93536243−29.964391720.00000000−141.42743062−18.392952690.00000000−148.68831187−6.356051580.00000000−152.409091625.824869020.00000000−152.3558836717.828981890.00000000−148.3919543229.347686330.00000000−140.4968846640.09648351−0.00000000−128.7794149849.82515047−0.00000000−113.4818040958.32554432−0.00000000−94.9755038765.436214050.00000000−73.7493133871.043530870.00000000−50.3916907375.078594500.00000000−25.5688464077.507513800.00000000−0.0000000078.317978730.0000000025.5688464077.507513800.0000000050.3916907375.078594500.0000000073.7493133871.043530870.0000000094.9755038765.436214050.00000000113.4818040958.32554432−0.00000000128.7794149849.825150470.00000000140.4968846640.096483510.00000000148.3919543229.34768633−0.00000000152.3558836717.828981890.00000000152.409091625.824869020.00000000148.68831187−6.356051580.00000000141.42743062−18.392952690.00000000130.93536243−29.964391720.00000000117.57413522−40.757912260.00000000101.73934320−50.477894910.0000000083.84419262−58.85273624−0.0000000064.30774000−65.642236650.0000000043.54745003−70.645848120.0000000021.97577930−73.711577460.00000000 An overall reflectivity of the projection optical unit 33 is 10.03%. The projection optical unit 33 has an image-side numerical aperture of 0.55. The image field 8 has an x-extent of two times 6.5 mm and a y-extent of 1.20 mm. The projection optical unit 33 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The projection optical unit 33 has exactly eight mirrors M1 to M8. The mirrors M2 and M3 on the one hand, and M5, M6 on the other hand are embodied as mirrors for grazing incidence and are arranged in each case as a mirror pair directly behind one another in the imaging beam path. The projection optical unit 33 has exactly four mirrors for grazing incidence, namely the mirrors M2, M3, M5 and M6. The mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence. In the projection optical unit 33, a stop 18 is arranged in the beam path between the mirrors M1 and M2, near the grazing incidence on the mirror M2. Alternatively or additionally, a stop can be arranged directly on the surface of the mirror M2. The projection optical unit 33 has a reducing imaging scale β=7.00. An angle of incidence of the chief rays 16 in the object plane 5 is 6.4°. In the yz-plane, an entrance pupil of the projection optical unit 33 lies 7700 mm in front of the object field 4 in the beam path of the illumination light. In the xy-plane (cf. FIG. 19), the entrance pupil lies 1775 mm after the object field in the imaging beam path of the projection optical unit 33. An extent of the chief rays 16 emanating from the object field 4 is therefore convergent both in the meridional section according to FIG. 18 and in the view according to FIG. 19. In the xz-section (cf. FIG. 19), the stop 18 can lie at a position displaced in the z-direction compared to its position in the yz-section. A z-distance between the object field 4 and the image field 8 is approximately 1290 mm. An object/image offset (dOIS) is approximately 1460 mm. A free working distance between the mirror M7 and the image field 8 is 50 mm. In the projection optical unit 33, a scanned RMS value for the wavefront aberration is at most 10 mλ and, on average, 8 mλ. A maximum distortion value is at most 0.03 nm in the x-direction and at most 0.08 nm in the y-direction. A telecentricity value in the x-direction is at most 0.79 mrad on the image field-side and a telecentricity value in the y-direction is at most 0.37 mrad on the image field-side. Further mirror data emerge from the following table. TABLE 7 for FIG. 18/19M1M2M3M4M5M6M7M8Maximum angle of incidence [deg]20.981.585.56.079.181.917.18.3Mirror extent (x) [mm]224.5366.3511.9611.2448.5225.0261.2652.2Mirror extent (y) [mm]219.5326.9514.483.3225.0308.6167.8642.2Maximum mirror diameter [mm]229.2368.5640.9611.3448.5310.5261.6652.5 There is an intermediate image 19 in the beam path in the imaging beam path region between the mirrors M3 and M4 in the yz-plane (FIG. 18) and in the imaging beam path region between the mirrors M6 and M7 in the xz-plane (FIG. 19). The intermediate image 19 can also be present in the region of a reflection on the mirror M5 in the yz-plane. The mirror M8 is obscured and includes a passage opening 17 for the passage of the illumination light 3 in the imaging beam path between the mirrors M6 and M7. A pupil obscuration of the projection optical unit 33 is 14% of the image-side numerical aperture of the projection optical unit 33. Only the last mirror M8 in the imaging beam path includes a passage opening 17 for the imaging light 3. All other mirrors M1 to M7 have a continuous reflection surface. The reflection surface of the mirror M8 is used around the passage opening 17 thereof. The mirrors M1, M3, M4 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The other mirrors M2, M5, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 for grazing incidence have very large radii and only constitute small deviations from plane reflection surfaces. A further embodiment of a projection optical unit 34, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIGS. 20 and 21. Components and functions which were already explained above in the context of FIGS. 1 to 19 are appropriately denoted by the same reference signs and are not discussed again in detail. FIG. 20 shows a meridional section of the projection optical unit 34. FIG. 21 shows a sagittal view of the projection optical unit 34. The projection optical unit 34 has a total of 8 mirrors M1 to M8 and, in terms of the basic design thereof, it is similar to e.g. the projection optical unit 7 according to FIG. 2. The projection optical unit 34 is embodied as anamorphic optical unit. In the yz-section according to FIG. 20, the projection optical unit 34 has a reducing imaging scale βy of 8.00. In the xz-plane (cf. FIG. 21) perpendicular thereto, the projection optical unit 34 has a reducing imaging scale βx of 4.00. In combination with a rotationally symmetric exit pupil of the projection optical unit 34, these different imaging scales βx, βy lead to an object-side numerical aperture being half the size in the yz-plane compared to the xz-plane, as emerges immediately from comparison between FIGS. 20 and 21. As a result of this, an advantageously small chief ray angle CRAO of 5.1° is obtained in the yz-plane. Advantages of an anamorphic projection lens connected herewith are also discussed in US 2013/0128251 A1, which is incorporated in its entirety in this application by reference. The anamorphic effect of the projection optical unit 34 is distributed to all optical surfaces of the mirrors M1 to M8. The mirrors M1 to M8 are once again embodied as free-form surface mirrors, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 34 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 20/21Exemplary embodimentFIG. 20/21NA0.55Wavelength13.5nmField dimension x26.0mmField dimension y1.2mmField curvature0.01/mmStopS9 TABLE 2 for FIG. 20/21SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−1133.327473040.00175233−1023.649343520.00196760REFLM74406.38826107−0.00045387690.91205607−0.00289482REFLM64739.61979766−0.0000869310074.88948477−0.00096360REFLM521144.94473278−0.0000203772950.75367779−0.00012733REFLM4−2867.384019760.00069495−4292.991984050.00046759REFLM3—0.00002356—0.00071385REFLM2−5190.311393640.000070247573.47590770−0.00144869REFLM1−5923.957148440.00031586−1898.454555100.00112603REFL TABLE 3a for FIG. 20/21CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−1133.327473004406.388261004739.61979800C7−1.37045485e−087.46796053e−08−2.88085237e−08C9−7.61541557e−09−1.45727199e−07−1.79062014e−08C10−7.69203582e−122.92796841e−104.42007445e−11C12−2.2092406e−111.13530474e−09−8.60191664e−12C14−1.03738908e−111.40909304e−09−4.58761129e−11C16−7.31775261e−15−1.31555425e−13−1.45618208e−13C18−1.17172291e−14−6.54062794e−134.24616003e−15C20−3.3983632e−15−3.50696381e−13−8.53811379e−14C21−9.15894595e−182.09018129e−16−9.75508493e−17C23−3.5991906e−172.50711167e−153.58424992e−16C25−3.77287782e−179.96925043e−15−1.56598011e−19C27−1.19641397e−177.56226507e−15−2.28737536e−16C29−5.75050439e−218.60467057e−19−9.76080298e−19C31−1.25790723e−204.36789592e−18−8.89549297e−19C33−1.03115676e−20−9.69395674e−18−3.40251221e−19C35−2.20183332e−21−3.27752356e−18−6.53545396e−19C36−8.33157821e−244.55264457e−224.12907772e−21C38−4.25998322e−237.24917406e−211.05886868e−20C40−6.98306225e−231.43589783e−203.05154424e−21C42−4.8336845e−23 8.43033547e−202.41517735e−23C44−1.40394078e−231.97591114e−19−1.6250366e−21C46−2.9814906e−27−4.16141287e−256.47812725e−23C48−1.1220021e−26−9.85706306e−242.80300383e−23C50−1.69711254e−264.09860054e−231.52687849e−23C52−8.57563301e−271.47027541e−227.02362488e−24C541.76715393e−28−6.99745034e−23−2.14951543e−24C55−6.6288945e−30 1.42110361e−27−2.82086233e−25C57−4.10869525e−29−4.51003428e−27−7.63377495e−25C59−9.17862325e−297.25467897e−26−2.77480674e−25C61−9.90356193e−293.9633015e−25 −3.52163248e−26C63−5.59488161e−299.95569594e−25−8.0432973e−28C65−7.22003129e−30−4.21378e−24 −2.74410127e−27C67−5.24619854e−33−8.35761662e−30−9.1548449e−28C69−2.01840485e−325.45404311e−29−5.39668302e−28C71−3.79282955e−32−2.97201132e−28−1.38362872e−27C73−2.44971235e−323.25227818e−28−3.68928781e−28C75−7.62727889e−33−8.7212421e−27−1.16531263e−28C77−5.7359611e−33 4.80554127e−27−4.17390192e−29C78−8.047176e−36−8.23504213e−337.06018116e−30C80−5.4403674e−35 2.3497042e−311.86040123e−29C82−1.67551366e−34 1.33047058e−301.3421476e−29C84−2.6900642e−34 5.04718453e−304.72484176e−30C86−2.38083651e−34−7.80809697e−304.75455568e−31C88−9.66546428e−351.17080611e−29−1.51988786e−31C90−2.31041974e−359.71583268e−29−2.31508815e−31C923.72879241e−391.17935322e−343.7709135e−34C94 1.5141875e−38−8.62572106e−36−7.82262879e−33C963.40542449e−383.38356865e−333.57455642e−32C983.58688134e−38−2.30440813e−341.60062441e−32C100−4.37695745e−39−7.67777542e−331.17807848e−33C102−9.00258499e−391.15560849e−314.06367757e−34C1049.73217887e−39−1.330225e−31−5.19167519e−34C105−3.15681223e−438.5001124e−38−6.1641406e−35C107−6.71085246e−42−3.50192205e−37−1.25784732e−34C1091.81013759e−41−3.77112897e−36−1.73593348e−34C1111.21188506e−40−1.79399564e−35−1.92852546e−34C1132.12299664e−404.42096118e−35−1.73174517e−35C1151.96801677e−403.78745494e−34−5.80388951e−36C1176.74687492e−41−4.55929668e−357.22309558e−37C1191.51520616e−41−4.50734906e−34−4.27492138e−37C121−3.77954419e−4500C123−5.73506768e−4400C125−1.67581738e−4300C127−2.67358045e−4300C129−2.40296709e−4300C131−8.92457112e−4400C133−1.44215565e−4400C135−1.25305206e−4400C136−1.34456467e−4700C138−1.15917807e−4600C140−4.9202134e−4600C142−1.261638e−4500C144−1.92457136e−4500C146−1.81299242e−4500C148−1.06311202e−4500C150−3.3131362e−4600C152−4.79751657e−4700 TABLE 3b for FIG. 20/21CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX21144.94473000−2867.38402000 −10853.57484000C7−8.13271685e−08−3.58841707e−085.29876767e−10C9−5.82176386e−08−7.04518606e−072.10519305e−09C109.37452981e−121.30052051e−12 −6.30399752e−12C123.00680111e−111.85556236e−10−5.20862433e−12C148.83038021e−11 3.5873503e−09−3.58045717e−12C164.50889445e−14−8.90737179e−151.13557992e−14C18−8.85586769e−15−1.37507133e−12−1.13089347e−16C20−2.84535698e−13−2.40161213e−111.2693646e−15C21−4.0259975e−179.84110093e−19 −1.07753791e−17C23−1.60627908e−161.18787038e−16 −4.13074732e−18C25−2.12462221e−161.07305967e−14−2.6198811e−18C277.88491781e−161.62876389e−13−1.51826315e−18C298.29816991e−20−1.42315568e−218.37815153e−21C314.09821249e−19−1.53159656e−182.70592478e−21C331.04060872e−18−1.00776807e−169.75607155e−22C35−2.28976537e−18−1.25474518e−151.00241528e−21C36−1.07018867e−221.36622356e−24−3.00882158e−23C38−4.94074303e−232.88428049e−232.10003322e−24C40−1.34527055e−211.98696867e−208.31511411e−24C42−4.60972729e−211.12695754e−183.79721863e−24C444.81654378e−211.6445151e−17−1.75074004e−25C461.01635491e−24−5.39059369e−272.00075589e−26C48−9.38768461e−256.02027898e−251.15956882e−26C50−7.09696896e−241.64761111e−22−5.38272606e−27C52−2.38402664e−243.42328361e−21−2.97501451e−27C54−2.26239625e−23−3.23207317e−19−5.02183701e−28C551.26386187e−281.71520917e−309.81733067e−30C57−2.83068278e−278.46560169e−29−3.36674489e−29C592.46204893e−26−1.62710492e−26−9.5444995e−29C619.95586051e−26−8.19930234e−24−8.78074754e−29C631.01878932e−251.62250965e−22−3.16474709e−29C651.91562178e−25−5.94818356e−21−4.32421248e−30C67−3.08120032e−30−1.7543011e−33−6.8780555e−32C694.41107086e−30−4.30759864e−30−8.633439e−32C71−2.847253e−29−2.73981339e−276.96849436e−32C734.4951507e−30−1.83904472e−258.79586218e−32C758.74287892e−29−8.91906155e−242.23940855e−32C77−6.9255095e−282.64874371e−224.81131842e−33C782.23687462e−34−1.85559281e−36−5.94735011e−35C80−7.0923897e−33−8.80329782e−351.42958234e−34C82−2.40355343e−311.32753328e−313.76354599e−34C84−1.33477305e−306.7062528e−294.22628687e−34C86−3.52926483e−304.70367187e−272.68539626e−34C88−4.04944897e−30 −1.60136059e−259.37754675e−35C90−2.28582075e−323.37934991e−241.01872115e−35C921.53053664e−351.03181863e−384.49578153e−37C941.90635627e−347.96148268e−374.15343568e−37C961.7721621e−335.60447131e−33−1.33200295e−37C987.04887896e−335.29126054e−31−4.53303133e−37C1001.53325023e−326.99281316e−29−2.18759113e−37C1021.55847895e−320−2.6400999e−38C1045.50738373e−330−5.86276203e−39C105−3.29469714e−392.0787905e−42−7.97361647e−43C107−6.03049846e−388.43168465e−40−9.19641517e−40C109−5.38471092e−37 −2.34623974e−37−7.68527335e−40C111−3.36030533e−36−1.09110522e−34−5.25251603e−40C113−1.05801312e−35 −2.66122693e−32−3.43774941e−40C115−2.05317853e−350−3.0477398e−40C117−1.88191883e−350−1.37941097e−40C119−9.0448429e−360−1.23378749e−41 TABLE 3c for FIG. 20/21CoefficientM2M1KY0.00000000 0.00000000 KX0.000000000.00000000RX−5190.31139400−5923.95714800C7−5.28973257e−09−9.34107203e−08C93.16117691e−08−3.08170947e−08C10−3.5113151e−112.15749003e−11C12−5.94839832e−11−4.16147444e−11C144.15396704e−11−9.60232617e−12C168.8719325e−14−1.38710348e−13C182.11910791e−14−4.21723708e−13C205.83626437e−141.56831697e−13C21−7.52771425e−172.2883345e−17C232.86726561e−17−7.98916101e−17C25−6.07859472e−17−6.15893157e−16C279.82616796e−176.98313821e−16C29−1.44090078e−21−1.67084874e−20C311.04190298e−191.24909603e−19C331.81953338e−20−5.55656679e−19C352.0422779e−19−3.23336886e−18C36−1.68993866e−23−3.08540907e−25C38−5.92115931e−23−6.92333888e−22C403.83068102e−23−1.17221531e−21C42−9.31939644e−231.57625031e−21C443.54805796e−22−4.85282982e−20C461.64542991e−257.61056694e−26C48−2.94838765e−251.5289645e−24C50−1.09554398e−248.66857734e−24C52−1.81472711e−242.18885048e−23C54−1.10156139e−252.98501444e−22C55−3.91686651e−28−3.84029125e−29C57−9.77388973e−288.12604652e−27C59−6.14630023e−284.79732982e−26C61−1.27909521e−273.3152603e−26C63−4.46201357e−27−2.9689908e−25C65−2.14425067e−282.24300892e−24C673.17153528e−32−3.98900423e−30C696.31254012e−30−4.30683926e−29C711.77074038e−29−3.09345554e−28C732.94127232e−29−3.2763638e−28C751.7371783e−291.84376033e−28C779.59406388e−30−9.29242727e−27C782.26427738e−336.44291133e−34C806.98015663e−33−7.26102976e−32C823.90295139e−33−8.26037127e−31C841.00563556e−32−2.47229342e−30C865.31207359e−321.36267497e−30C884.68167146e−321.1558863e−29C902.22750927e−32−6.48766222e−29C924.94909078e−362.123736e−35C94−2.40458792e−352.73287712e−34C96−6.91070231e−352.28462552e−33C98−1.61918658e−346.85274826e−33C100−1.44300155e−34−4.32046035e−33C102−7.93406187e−35−1.07655048e−32C104−1.66530071e−351.27235198e−31C1055.86498685e−40 −4.29231126e−39C107−1.54194375e−382.35882135e−37C109−7.13318326e−394.70203204e−36C111−1.43456171e−382.37591177e−35C113−1.90286626e−373.22170482e−35C115−2.94354338e−37−8.87390817e−35C117−2.19039138e−37−1.98534313e−34C119−6.06928085e−388.31104332e−34 TABLE 4a for FIG. 20/21SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.35696376928.41215449M70.00000000−194.00592810123.62549517M60.00000000110.738076781485.21127288M50.00000000410.248608091906.05090667M40.00000000989.832150982227.66851159M30.00000000−480.767943371725.54436925M20.00000000−1586.00680196983.72854005Stop0.00000000−1833.30051904630.89726836M10.00000000−2256.9699097248.20891557Object plane0.00000000−2433.049409261809.33615616 TABLE 4b for FIG. 20/21SurfaceTLA[deg]TLB[deg]TLC[deg]Image plane−0.000000000.00000000−0.00000000M8−6.811586010.00000000−0.00000000M7166.853437700.00000000−0.00000000M665.470676710.00000000−0.00000000M541.133887920.00000000−0.00000000M4−66.252596540.00000000−0.00000000M326.326468370.00000000−0.00000000M243.987932120.00000000−0.00000000Stop17.853484920.00000000−0.00000000M1165.031704760.00000000−0.00000000Object plane 0.841838540.00000000−0.00000000 TABLE 5 for FIG. 20/21SurfaceÊinfallswinkel [deg]ReflectivityM86.791464570.66081301M70.472552040.66566232M678.111280130.85242200M577.565691420.84450121M44.903690750.66322257M382.654501700.91169087M279.496919490.87161748M120.678871470.60924189Overall transmission0.1017 TABLE 6 for FIG. 20/21X[mm]Y[mm]Z[mm]0.00000000−127.836041170.00000000−42.47230052−125.946423280.00000000−84.13944596−120.365300560.00000000−124.19202701−111.343411360.00000000−161.81430598−99.261414570.00000000−196.18564839−84.586938840.00000000−226.48648672−67.834454120.00000000−251.91061812−49.537593380.00000000−271.68668618−30.235307790.00000000−285.11143299−10.467431520.00000000−291.595212769.228260340.00000000−290.7162473028.327444810.00000000−282.2741153846.342754470.00000000−266.3287255062.849723740.00000000−243.2138332777.505309040.00000000−213.5226482290.059812660.00000000−178.07097077100.361361370.00000000−137.84767730108.346150510.00000000−93.96325338114.013434100.00000000−47.60455320117.39298190−0.00000000−0.00000000118.515400250.0000000047.60455320117.39298190−0.0000000093.96325338114.013434100.00000000137.84767730108.346150510.00000000178.07097077100.361361370.00000000213.5226482290.059812660.00000000243.2138332777.505309040.00000000266.3287255062.849723740.00000000282.2741153846.342754470.00000000290.7162473028.327444810.00000000291.595212769.228260340.00000000285.11143299−10.467431520.00000000271.68668618−30.235307790.00000000251.91061812−49.537593380.00000000226.48648672−67.834454120.00000000196.18564839−84.586938840.00000000161.81430598−99.261414570.00000000124.19202701−111.343411360.0000000084.13944596−120.365300560.0000000042.47230052−125.946423280.00000000 An overall reflectivity of the projection optical unit 34 is 10.17%. The projection optical unit 34 has an image-side numerical aperture of 0.55. The image field 8 has an x-extent of two times 13 mm and a y-extent of 1.20 mm. The projection optical unit 34 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The projection optical unit 34 has exactly eight mirrors M1 to M8. The mirrors M2 and M3 on the one hand, and M5, M6 on the other hand are embodied as mirrors for grazing incidence and are arranged in each case as a mirror pair directly behind one another in the imaging beam path. The projection optical unit 34 has exactly four mirrors for grazing incidence, namely the mirrors M2, M3, M5 and M6. The mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence. In the projection optical unit 34, a stop 18 is arranged in the beam path between the mirrors M1 and M2, near the grazing incidence on the mirror M2. Alternatively or additionally, a stop can be arranged directly on the surface of the mirror M2. In the xz-plane (cf. FIG. 21), an entrance pupil of the projection optical unit 34 lies 2740 mm in front of the object field 4 in the beam path of the illumination light. In the yz-plane, the entrance pupil lies 5430 mm after the object field in the imaging beam path of the projection optical unit 34. An extent of the chief rays 16 emanating from the object field 4 is therefore convergent both in the meridional section according to FIG. 20 and in the view according to FIG. 21. In the xz-section (cf. FIG. 21), the stop 18 can lie at a position displaced in the z-direction compared to its position in the yz-section. The stop 18 is planar and tilted with respect to the image field. The long extent of the stop 18 in the x-direction is 583.18 mm. The overall extent of the stop 18 in the y-direction is 238.85 mm. A z-distance between the object field 4 and the image field 8 is approximately 1850 mm. An object/image offset (dOIS) is approximately 2400 mm. A free working distance between the mirror M7 and the image field 8 is 83 mm. In the projection optical unit 34, a scanned RMS value for the wavefront aberration is at most 8 mλ and, on average, 7 mλ. A maximum distortion value is at most 0.10 nm in the x-direction and at most 0.10 nm in the y-direction. A telecentricity value in the x-direction is at most 1.58 mrad on the image field-side and a telecentricity value in the y-direction is at most 0.15 mrad on the image field-side. Further mirror data emerge from the following table. TABLE 7 for FIG. 20/21M1M2M3M4M5M6M7M8Maximum angle of incidence [deg]20.981.983.87.079.881.217.28.3Mirror extent (x) [mm]525.7662.4847.1984.1675.6325.0482.91074.4Mirror extent (y) [mm]268.1512.7856.166.4336.1466.1277.41053.4Maximum mirror diameter [mm]525.8662.5926.3984.1675.6470.0483.01076.0 There is an intermediate image 19 in the beam path in the region of a reflection on the mirror M4 in the yz-plane (FIG. 20) and in the imaging beam path region between the mirrors M6 and M7 parallel to the xz-plane (FIG. 21). The mirror M8 is obscured and includes a passage opening 17 for the passage of the illumination light 3 in the imaging beam path between the mirrors M6 and M7. Only the last mirror M8 in the imaging beam path includes a passage opening 17 for the imaging light 3. All other mirrors M1 to M7 have a continuous reflection surface. The reflection surface of the mirror M8 is used around the passage opening 17 thereof. The mirrors M1, M3, M4 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The other mirrors M2, M5, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 for grazing incidence have very large radii and only constitute small deviations from plane reflection surfaces. FIG. 21A shows edge contours of the surfaces on the mirrors M1 to M8 of the projection optical unit 34 which are in each case impinged upon by illumination light 3, i.e. the so-called footprints of the mirrors M1 to M8. These edge contours are in each case depicted in an x/y-diagram which corresponds to the local x- and y-coordinates of the respective mirror M1 to M8. The illustrations are true to scale in millimeters. The mirrors M2, M3 and M8 have an x/y-aspect ratio which does not deviate, or only deviates slightly, from the value 1. The mirrors M1 and M5 and also M7 have an x/y-aspect ratio of approximately 2. The mirror M4 has an x/y-aspect ratio of approximately 15. The mirror M6 has an x/y-aspect ratio of approximately 0.7. A further embodiment of a projection optical unit 35, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIGS. 22 and 23. Components and functions which were already explained above in the context of FIGS. 1 to 21A are appropriately denoted by the same reference signs and are not discussed again in detail. FIG. 22 shows a meridional section of the projection optical unit 35. FIG. 23 shows a sagittal view of the projection optical unit 35. The projection optical unit 35 has a total of 8 mirrors M1 to M8 and, in terms of the basic design thereof, it is similar to e.g. the projection optical unit 7 according to FIG. 2. The projection optical unit 35 is embodied as anamorphic optical unit. In the yz-section according to FIG. 22, the projection optical unit 35 has a reducing imaging scale βy of 6.00. In the xz-plane (cf. FIG. 23) perpendicular thereto, the projection optical unit 35 has a reducing imaging scale βx of 4.00. These different imaging scales βx, βy lead to an object-side numerical aperture being smaller in the yz-plane than in the xz-plane, as emerges immediately from comparison between FIGS. 22 and 23. As a result of this, an advantageously small chief ray angle CRAO of 6.3° is obtained in the yz-plane. The anamorphic effect of the projection optical unit 35 is distributed to all optical surfaces of the mirrors M1 to M8. The mirrors M1 to M8 are once again embodied as free-form surface mirrors, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 35 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 22/23Exemplary embodimentFIG. 22/23NA0.49Wavelength13.5nmField dimension x26.0mmField dimension y1.6mmField curvature0.01/mmStopS9 TABLE 2 for FIG. 22/23SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−1121.378896410.00177101−1023.613019170.00196766REFLM74813.84973129−0.00041545689.47522791−0.00290086REFLM67961.52706392−0.0000519610472.69061413−0.00092320REFLM563451.73749313−0.00000674—0.00013019REFLM4−2879.298686120.00069194−5323.526775280.00037714REFLM3—0.00002283—0.00079438REFLM2−6051.136299010.000057475373.11013087−0.00214085REFLM1−7070.710426940.00026365−1740.131146180.00123306REFL TABLE 3a for FIG. 22/23CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−1121.378896004813.849731007961.52706400C7 −1.18303428e−081.38677591e−074.50959592e−08C9 −9.04489424e−09−2.49942276e−07−3.22908374e−08C10 −5.56852211e−123.59231824e−101.39261473e−10C12 −2.2156858e−111.11674106e−09−1.58384659e−10C14 −6.4485662e−127.68944651e−10−4.64967002e−11C16 −5.99476799e−15−1.25877621e−13−6.14806551e−13C18 −1.17154189e−14−8.32139172e−136.1577807e−14C20 −6.35164457e−15−1.04560226e−12−1.56127394e−13C21 −1.01505313e−172.28624052e−16−3.24656403e−16C23 −3.58157787e−172.8674558e−151.48986258e−15C25 −3.28325694e−177.19573474e−15−4.96219439e−16C27 −7.73325248e−183.33755229e−15−3.25304321e−16C29 −4.20439801e−211.11781377e−181.99348552e−18C31 −1.22366176e−202.12044512e−18−3.13360785e−18C33 −1.33129381e−20−1.15534587e−17−6.05173065e−20C35 −4.96149215e−21−1.08505991e−17−7.96524541e−19C36 −8.64520812e−241.17916451e−214.32310419e−22C38 −4.20401284e−237.44374387e−21−6.15076012e−21C40 −6.32215484e−231.2747226e−206.73662583e−21C42 −3.86493292e−234.95955342e−20−6.33665608e−22C44 −7.91782043e−243.24541865e−20−2.74989457e−21C46 −2.33453384e−27−2.60631426e−24−3.91508173e−24C48 −1.2111516e−26−2.33541368e−231.99392725e−24C50 −2.11068645e−26−3.6973872e−23−2.14301967e−23C52 −1.4752144e−26−7.99170432e−23−1.74710333e−23C54 −2.78281412e−272.51969672e−22−8.23051883e−24C55 −9.3090786e−30−5.20473578e−28−3.87769553e−27C57 −4.82558402e−297.88777677e−272.66612565e−27C59 −1.01014959e−288.54406184e−26−5.91238257e−26C61 −1.01884048e−282.13476338e−25−9.52500131e−26C63 −4.93105369e−291.13995538e−24−5.50812191e−26C65 −8.3687505e−30−5.12746033e−25−2.47004376e−26C67 −7.38344559e−341.47520112e−297.1085924e−29C69 −5.65274775e−331.61742091e−283.53277318e−28C71 −1.37764606e−323.44509275e−282.93969176e−28C73 −1.94275915e−325.48602534e−282.20566794e−28C75 −1.39583588e−32−5.18813001e−271.06448096e−28C77 −4.27384745e−33−4.35332176e−27−9.78424185e−29C78 −8.54420454e−378.35040636e−332.58890164e−32C80 −2.31228001e−351.76870158e−31−5.38428428e−31C82 −5.6838319e−351.22604787e−31−5.84517587e−31C84 −7.66291033e−35−2.91896005e−311.4024938e−30C86 −6.31178383e−35−2.08128795e−302.01491828e−30C88 −3.30768172e−355.15327359e−302.88799603e−31C90 −6.60293612e−366.34662561e−30−1.56186793e−31C92 −6.89240073e−3900C94 −2.22316469e−3800C96 −6.89815447e−3800C98 −9.26549465e−3800C100−5.535508e−3800C102−1.37382595e−3800C104−2.77235312e−3900C105−1.32648355e−4100C107−1.08701271e−4000C109−3.57659282e−4000C111−6.22339725e−4000C113−6.31535758e−4000C115−3.50492314e−4000C117−8.26138611e−4100C119−4.09212691e−4200 TABLE 3b for FIG. 22/23CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX63451.73749000−2879.29868600−11586.49414000C7 −9.65439819e−08−5.21928877e−08−5.17057407e−09C9 −4.4513793e−08−6.81657841e−073.86113841e−09C102.42543649e−117.64041622e−13−1.02639927e−11C128.44725177e−11 1.99750296e−10−4.79572504e−12C147.04127351e−11 3.06515788e−09−4.42190289e−12C16−3.41516947e−14−2.37609081e−148.82004007e−15C18−1.98478544e−13−1.56031785e−12−9.88386961e−16C20−2.68645804e−13 −1.9204511e−111.72706853e−15C21−3.59158408e−17 1.13052962e−183.41000671e−18C233.64471697e−17 2.10998699e−16−3.70359019e−18C254.18205639e−16 1.08957074e−14−1.71679008e−18C279.35618672e−16 1.32227766e−13−1.70575731e−18C291.153762e−19−1.205391e−20−4.77242785e−21C311.08387142e−20−2.2598668e−181.1307014e−21C33−1.29076401e−18−9.90347004e−171.61393734e−22C35−3.11679607e−18−5.16190495e−161.06465407e−21C363.2037253e−232.44573623e−25−5.23904465e−24C38−3.00422396e−222.02451858e−226.39454501e−24C40−5.56453309e−222.77540352e−20−2.38654616e−26C421.15075161e−21 7.77510206e−19−8.27248728e−25C44−8.45545916e−21 1.83631375e−16−1.10257267e−24C46−7.17799435e−26−6.16666974e−273.71377518e−27C484.41056949e−25−1.77193124e−242.26385586e−29C503.20645297e−24−7.22070937e−259.11823578e−28C52−6.68431649e−24−1.47635262e−205.14270429e−28C548.10978715e−235.0776662e−184.13766527e−28C55−8.00938486e−292.30519335e−311.16666839e−29C57−4.31210476e−285.98498871e−29−1.67242338e−29C591.263643e−27−2.81679351e−27−1.76007666e−30C611.612983e−263.572795e−24−2.19437814e−30C632.7883773e−25−5.88261071e−22−8.93045154e−31C651.0678073e−24−1.29361634e−193.33090397e−32C674.23448748e−31−5.49562737e−33−4.02324014e−34C696.71940992e−30−4.72770157e−30−6.06669725e−33C71−5.19192758e−29−1.4523395e−27−5.05696725e−33C731.0131755e−29−1.68084682e−25−2.25708995e−34C75−3.04215249e−27−8.27631336e−249.90529604e−34C77−9.47988848e−27−6.68913918e−211.03314337e−33C781.37830298e−343.39532895e−38−3.00501581e−35C80−2.20614706e−332.60606795e−343.47983183e−35C82−1.55885934e−321.18728779e−319.0614728e−36C842.36759125e−31−9.90754189e−306.42501344e−36C86−8.92393833e−31−2.12722713e−272.44225001e−36C881.11751611e−292.57988212e−25−1.1318051e−36C901.68895246e−29−6.02795443e−23−1.48883018e−36 TABLE 3c for FIG. 22/23CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−6051.13629900−7070.71042700C7 5.13565486e−08−5.53709138e−08C9 8.48166415e−08−2.81784911e−08C10−7.13439177e−111.35470045e−11C12−6.78217449e−112.22349088e−12C141.07389017e−10−2.17100764e−11C169.40090645e−14−9.25413819e−14C184.12391946e−14−1.96114428e−13C201.58260544e−131.03943487e−13C213.47522486e−181.82335443e−17C236.4536786e−17 −9.18926095e−17C25−9.48899205e−171.8538804e−16C272.49339094e−16−1.11389293e−16C295.35403925e−201.8436518e−20C317.5637834e−201.96646409e−19C33−3.4158977e−20−9.81835487e−20C354.85861223e−191.66148938e−20C36−4.94601583e−23−7.08072737e−23C38−4.05348385e−23−4.11801448e−22C40−1.32203024e−22−3.45175171e−22C42−4.03609525e−22 2.73466405e−21C441.11739328e−212.14025934e−21C464.93708892e−25−4.4788586e−25C488.43130272e−25−2.07813692e−24C503.73873009e−25−1.03853204e−24C52−6.68290603e−258.00799065e−24C542.70267769e−24 8.41515359e−24C557.69118669e−28 1.51282519e−28C57−6.45916145e−283.17074481e−27C59−2.33699309e−271.22333041e−26C61−1.59593012e−272.79500485e−26C63−1.26314552e−273.67365838e−26C656.27135853e−276.16865377e−27C67−4.95148641e−319.10808295e−31C69−1.46516796e−301.89542207e−29C71−4.91881917e−313.64294099e−29C735.75845525e−30 1.8163786e−28C753.15049294e−301.86166005e−28C771.11362439e−29 6.30936726e−29C78−5.94716839e−332.0215274e−34C808.05983005e−33−1.50601813e−32C821.4626007e−32−7.53087591e−32C845.40117622e−33−9.52174202e−32C863.4651056e−333.12650323e−31C881.81935676e−34 1.56079676e−30C908.55586176e−33−9.50142408e−31 TABLE 4a for FIG. 22/23SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.43487770929.54103257M70.00000000−195.16970097122.97869898M60.00000000111.859857621489.32638973M50.00000000410.819497881904.78959323M40.00000000992.157308722222.31723561M30.00000000−482.567072701729.00568653M20.00000000−1585.17397046981.97338980Stop0.00000000−1727.72829897783.13904832M10.00000000−2266.5270112558.05513346Object plane0.00000000−2431.231306071600.02829943 TABLE 4b for FIG. 22/23SurfaceTLA [deg]TLB [deg]TLC [deg]Image plane−0.000000000.00000000−0.00000000M8−6.813305810.00000000−0.00000000M7166.926452950.00000000−0.00000000M665.447618200.00000000−0.00000000M541.177682890.00000000−0.00000000M4−66.325915760.00000000−0.00000000M326.393709490.00000000−0.00000000M243.842836450.00000000−0.00000000Stop16.956414690.00000000−0.00000000M1164.876248170.00000000−0.00000000Object plane0.143720630.00000000−0.00000000 TABLE 5 for FIG. 22/23SurfaceAngle of incidence [deg]ReflectivityM86.788791740.66081702M70.474690610.66566222M678.061668140.85171082M577.646396090.84568699M45.026066610.66309175M382.399901310.90859365M279.987272280.87813250M121.235466590.60543423Overall transmission0.1015 TABLE 6 for FIG. 22/23X[mm]Y[mm]Z[mm]0.00000000−103.180457150.00000000−38.19587382−101.809114860.00000000−75.61417532−97.738372680.00000000−111.48060482−91.096403070.00000000−145.02805526−82.090290730.00000000−175.50222111−70.994754030.00000000−202.17051799−58.137088690.00000000−224.33612423−43.882143700.00000000−241.35841193−28.620510480.00000000−252.67986085−12.760353340.00000000−257.857953563.278891450.00000000−256.5986727119.073561990.00000000−248.7864835634.206263110.00000000−234.5051423248.281880250.00000000−214.0451654260.948748280.00000000−187.8968833771.920907220.00000000−156.7311795680.995265220.00000000−121.3719055188.057082870.00000000−82.7642961793.070428160.00000000−41.9427856196.053593140.00000000−0.0000000097.04230242−0.0000000041.9427856196.053593140.0000000082.7642961793.07042816−0.00000000121.3719055188.057082870.00000000156.7311795680.99526522−0.00000000187.8968833771.920907220.00000000214.0451654260.94874828−0.00000000234.5051423248.281880250.00000000248.7864835634.206263110.00000000256.5986727119.073561990.00000000257.857953563.278891450.00000000252.67986085−12.760353340.00000000241.35841193−28.620510480.00000000224.33612423−43.882143700.00000000202.17051799−58.137088690.00000000175.50222111−70.994754030.00000000145.02805526−82.090290730.00000000111.48060482−91.096403070.0000000075.61417532−97.738372680.0000000038.19587382−101.809114860.00000000 An overall reflectivity of the projection optical unit 35 is 10.15%. The projection optical unit 35 has an image-side numerical aperture of 0.49. The image field 8 has an x-extent of two times 13 mm and a y-extent of 1.20 mm. The projection optical unit 35 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The projection optical unit 35 has exactly eight mirrors M1 to M8. The mirrors M2 and M3 on the one hand, and M5, M6 on the other hand are embodied as mirrors for grazing incidence and are arranged in each case as a mirror pair directly behind one another in the imaging beam path. The projection optical unit 35 has exactly four mirrors for grazing incidence, namely the mirrors M2, M3, M5 and M6. The mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence. In the projection optical unit 35, a stop 18 is arranged in the beam path between the mirrors M1 and M2, near the grazing incidence on the mirror M2. Alternatively or additionally, a stop can be arranged directly on the surface of the mirror M2. An angle of incidence of the chief rays 16 in the object plane 5 is 6.3°. In the meridional section according to FIG. 22, the chief rays extend between the object field 4 and the mirror M1 in a divergent manner. In the yz-plane, an entrance pupil of the projection optical unit 35 lies approximately −6640 mm in front of the object field 4 in the beam path of the illumination light. In the xz-plane (cf. FIG. 23), the entrance pupil lies approximately 2750 mm after the object field in the imaging beam path of the projection optical unit 35. The mirror M8 defines an image-side obscuration which is less than 15% of the image-side numerical aperture of the projection optical unit 35 in the x-dimension. In the xz-section (cf. FIG. 23), the stop 18 can lie at a position displaced in the z-direction compared to its position in the yz-section. A z-distance between the object field 4 and the image field 8 is approximately 1600 mm. An object/image offset (dOIS) is approximately 2430 mm. A free working distance between the mirror M7 and the image field 8 is 88 mm. In the projection optical unit 35, a scanned RMS value for the wavefront aberration is at most 10 mλ and, on average, 7 mλ. A maximum distortion value is at most 0.27 nm in the x-direction and at most 0.17 nm in the y-direction. A telecentricity value in the x-direction is at most 0.01 mrad on the image field-side and a telecentricity value in the y-direction is at most 0.06 mrad on the image field-side. Further mirror data emerge from the following table. TABLE 7 for FIG. 22/23M1M2M3M4M5M6M7M8Maximum angle of incidence [deg]21.682.482.87.480.181.414.88.5Mirror extent (x) [mm]427.1563.6810.3985.6705.3352.4414.1951.7Mirror extent (y) [mm]286.3514.21144.852.4219.4367.8248.0928.2Maximum mirror diameter [mm]427.5569.81172.5985.6705.3390.7414.3951.9 There is an intermediate image 19 in the beam path in the region of a reflection on the mirror M5 in the yz-plane (FIG. 22) and in the imaging beam path region between the mirrors M6 and M7 in the xz-plane (FIG. 23). The mirror M8 is obscured and includes a passage opening 17 for the passage of the illumination light 3 in the imaging beam path between the mirrors M6 and M7. A value for the obscuration is 15%. Only the last mirror M8 in the imaging beam path includes a passage opening 17 for the imaging light 3. All other mirrors M1 to M7 have a continuous reflection surface. The reflection surface of the mirror M8 is used around the passage opening 17 thereof. The mirrors M1, M3, M4, M5 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The other mirrors M2, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 for grazing incidence have very large radii and only constitute small deviations from plane reflection surfaces. A further embodiment of a projection optical unit 36, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIGS. 24 and 25. Components and functions which were already explained above in the context of FIGS. 1 to 23 are appropriately denoted by the same reference signs and are not discussed again in detail. FIG. 24 shows a meridional section of the projection optical unit 36. FIG. 25 shows a sagittal view of the projection optical unit 36. The projection optical unit 36 has a total of 8 mirrors M1 to M8 and, in terms of the basic design thereof, it is similar to e.g. the projection optical unit 7 according to FIG. 2. The projection optical unit 36 is embodied as anamorphic optical unit. In the yz-section according to FIG. 24, the projection optical unit 36 has a reducing imaging scale βy of 6.00. In the xz-plane (cf. FIG. 25) perpendicular thereto, the projection optical unit 36 has a reducing imaging scale βx of 5.40. These different imaging scales βx, βy lead to an object-side numerical aperture being smaller in the yz-plane than in the xz-plane, as emerges from comparison between FIGS. 24 and 25. As a result of this, an advantageously small chief ray angle CRAO of 6.7° is obtained in the yz-plane. The anamorphic effect of the projection optical unit 36 is distributed to all optical surfaces of the mirrors M1 to M8. The mirrors M1 to M8 are once again embodied as free-form surface mirrors, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 36 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 24/25Exemplary embodimentFIG. 24/25NA0.5Wavelength13.5nmField dimension x26.0mmField dimension y1.2mmField curvature0.01/mmStopS9 TABLE 2 for FIG. 24/25SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−898.653844510.00220986−841.560292760.00239341REFLM72519.21415981−0.00079387549.64538748−0.00363883REFLM65235.46738689−0.0000732118583.02763769−0.00056159REFLM510320.35903473−0.000045337043.08337008−0.00121403REFLM4−2368.584508240.00084156−1677.618568780.00119617REFLM3—0.00001752—0.00044930REFLM2−3162.965792520.000114786044.71230342−0.00182278REFLM1—0.00005542−1659.850104490.00128773REFL TABLE 3a for FIG. 24/25CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−898.65384450 2519.214160005235.46738700C7 −3.09391603e−08−1.79559389e−071.24390263e−08C9 −7.26824159e−096.05374011e−081.79529464e−08C10 −9.17661523e−127.52464303e−107.73452408e−11C12 −2.9215991e−112.51411627e−095.01854597e−11C14 −1.54578064e−111.71853031e−09 1.59214758e−11C16 −3.78292895e−14−1.78811844e−12−1.78827188e−13C18 −3.15725802e−14−3.28279723e−12 1.1629587e−13C20 −3.25627497e−151.74708334e−122.90732297e−14C21 −2.16930672e−171.21979378e−16−1.17216554e−16C23 −7.40935074e−178.73459133e−156.3593323e−16C25 −8.27264393e−172.78760075e−143.63957206e−16C27 −2.47378025e−177.97309374e−154.64399505e−17C29 −4.00833778e−203.04883362e−181.20940283e−18C31 −6.74348668e−201.05351029e−17−7.33386432e−19C33 −3.33712007e−20−2.53301039e−171.04598017e−18C35 −1.60060561e−215.51279308e−183.15382288e−20C36 −3.38618723e−231.09644503e−202.10543991e−21C38 −1.52108183e−225.20557325e−20−7.17116902e−21C40 −2.50184393e−229.91293267e−201.9344533e−21C42 −1.55242331e−224.49100492e−205.1810958e−21C44 −3.21754195e−236.12504902e−204.00057253e−22C46 −2.56622324e−26−2.34811653e−23−2.20054661e−23C48 −7.12044814e−26−1.38827791e−222.11379653e−23C50 −8.35229848e−26−2.27120568e−224.24710944e−24C52 −3.25877822e−261.63931776e−212.81218781e−23C54 2.31523308e−272.29596466e−214.11520106e−24C55 −3.22044427e−29−8.38570398e−26−3.16289259e−26C57 −9.9283758e−29−3.98833111e−257.96014291e−26C59 −1.59623677e−284.49981655e−25−2.36125333e−26C61 −2.26350041e−284.86885671e−242.20987927e−26C63 −2.16360896e−284.81078139e−24 9.17694081e−26C65 −7.19034294e−293.12706869e−241.70276521e−26C67 −1.66086944e−31−1.00921794e−281.20992206e−28C69 −7.09674851e−312.62297907e−28−3.33093899e−28C71 −1.00405146e−301.59366409e−27 7.45906143e−29C73 −4.84392005e−316.24841362e−27−1.78519939e−28C75 1.6840288e−32 9.81013953e−271.67183371e−28C77 5.33123321e−32−2.64352603e−263.33232457e−29C78 −7.76624666e−357.70090407e−312.36244673e−31C80 −1.37504248e−337.418665e−303.27117525e−31C82 −4.9730902e−331.12937368e−29 1.58945015e−30C84 −6.93445436e−33−2.16643844e−29−1.71056833e−30C86 −4.05050995e−33−1.48561291e−28−4.22081835e−31C88 −7.44238878e−34−3.70834394e−28 1.38420773e−31C90 8.08789051e−35−3.48344195e−282.57211573e−32C92 3.79975278e−3700C94 2.54205485e−3600C96 5.28074116e−3600C98 4.78458863e−3600C1001.78186461e−3600C1021.09169331e−3800C104−1.69802736e−3700C105−3.93526201e−4100C1073.66634759e−3900C1091.99100717e−3800C1113.88960174e−3800C1133.36275392e−3800C1151.23397826e−3800C1175.74500356e−4000C119−5.43216154e−4000C121−8.13063603e−4300C123−6.57853328e−4200C125−1.84219693e−4100C127−2.4128622e−4100C129−1.58805249e−4100C131−4.8328677e−4200C133−1.37774875e−4400C1353.70992132e−4300C136−1.82426978e−4600C138−8.82948521e−4500C140−5.13522224e−4400C142−1.2576407e−4300C144−1.54936749e−4300C146−1.00539254e−4300C148−3.21138841e−4400C150−2.48902466e−4500C1528.34369753e−4600 TABLE 3b for FIG. 24/25CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX10320.35903000−2368.58450800−14606.85238000C7 −9.43984452e−08−3.19780054e−083.42335843e−09C9 −3.73977119e−08−1.20873717e−085.71457986e−09C102.4885219e−11 3.51515054e−13−2.7196639e−11C123.31374515e−113.35936518e−11−8.28556705e−12C141.23001091e−10−4.20689147e−10−4.37520677e−12C169.60921501e−146.35312252e−163.97165731e−14C183.06969842e−14−2.04642026e−134.6038851e−16C20−1.81914837e−131.42057888e−124.04652695e−15C21−1.50139489e−16 3.20784131e−18 −6.41123154e−17C23−3.67530123e−16−1.59859373e−17−6.98459168e−18C25−5.85422242e−16 5.10844386e−16−6.91809193e−18C275.96794634e−16−8.63505265e−15 −3.65944728e−18C298.05074272e−199.21434731e−216.08393666e−20C319.67423637e−19−6.41403775e−201.32184653e−20C332.74697274e−18−3.17400432e−185.64881549e−21C35−2.10574097e−18−5.68113418e−184.62810551e−21C36−4.19331352e−225.4673575e−24 −1.20159738e−22C38−1.48291097e−21−5.66829369e−239.99813448e−24C40−8.89078399e−233.3289796e−21−1.51187874e−24C42−1.30043929e−202.13230879e−202.57105484e−24C44−5.61941157e−231.28852422e−18−2.83232079e−24C461.22910541e−24−3.93269304e−26−8.4259963e−26C482.63475255e−251.29025934e−24−6.73035076e−27C50−1.61930052e−249.58130418e−23−2.23952211e−26C529.54851986e−23−6.49564266e−22−3.32643796e−26C546.18740883e−232.13466405e−20−1.30243029e−26C55−1.88937216e−284.62453335e−304.32699323e−29C577.92134564e−27−6.42166267e−282.58106954e−28C59−3.81767476e−26−3.40516712e−27−1.33435452e−28C61−7.40042015e−26 1.13636915e−25−1.31816559e−28C63−5.91737902e−25−2.28464211e−23−6.13175237e−30C65−5.90657031e−26 3.90274961e−23−7.57941398e−30C67−4.71910372e−30−4.00537288e−32−3.78181987e−31C69−3.80842075e−29 9.29769453e−313.15234014e−32C713.45306237e−28−9.14633256e−286.81155634e−31C734.06923505e−28−7.07463203e−273.52501713e−31C751.89818188e−273.11226568e−254.51613912e−31C77−1.59359386e−27−1.02694094e−238.58516649e−32C785.39005499e−347.60475402e−365.47282581e−35C801.28802722e−321.82429692e−332.22708016e−34C828.88526683e−32−1.0368376e−31−5.0870717e−34C84−1.07852034e−30−7.6912987e−30−3.01511969e−34C868.12932285e−327.77307244e−29−6.5410886e−34C88−2.93141855e−302.55070847e−27−5.55696921e−34C904.98139974e−30−9.99949267e−26−6.9232932e−35 TABLE 3c for FIG. 24/25CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−3162.96579300−33768.32491000C7 −5.63006995e−09−1.85162177e−07C9 2.52603119e−08−5.82002845e−08C10−1.63939568e−102.19843459e−11C12−1.45434544e−104.34395623e−12C143.07914787e−11−3.90398966e−11C161.19978873e−13−4.02854058e−13C182.91665979e−14−3.53269108e−13C207.14507418e−14−8.06536713e−14C21−1.26157584e−161.50658497e−16C23−7.76330156e−171.09978734e−17C25−1.72160645e−16−2.64878411e−16C271.30511683e−16−9.7675593e−17C294.97077758e−191.94104108e−19C317.3469712e−192.13721124e−19C33−1.6248826e−19−1.17732749e−18C352.44811103e−193.66216487e−19C362.74716093e−22−1.46887345e−21C38−4.42878488e−22−2.52169606e−21C404.31546413e−22−4.89313142e−21C42−1.2501295e−21−3.10103922e−21C441.72029553e−22−9.49213909e−21C46−1.32233821e−247.79166706e−25C48−5.97471372e−254.56312854e−25C50−1.02312238e−25 7.6643113e−24C52−5.04494501e−243.67536202e−23C543.49233317e−251.65632978e−23C55−5.35422344e−272.17389317e−26C57−1.44886077e−266.10103532e−26C59−1.68015387e−263.72656392e−26C61−1.69820125e−274.8382551e−26C63−4.06228599e−277.94819696e−26C654.73934877e−279.99358955e−26C671.48192042e−29−5.37391586e−30C692.75293606e−29−7.66284246e−29C713.29720353e−29−4.12938667e−28C736.35559729e−29−6.45953223e−28C753.17464557e−29−8.69448659e−28C771.55333959e−29−5.55442684e−28C782.17458628e−32−1.65616708e−31C808.59099937e−32−4.90253105e−31C821.25586211e−31 8.5337234e−32C841.36897347e−319.42500117e−31C861.31238686e−317.66948893e−31C885.58974151e−328.26964826e−31C901.55246521e−325.2747466e−31 TABLE 4a for FIG. 24/25SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.00000000−1.67688632764.65279783M70.00000000−161.54058747101.44072569M60.00000000107.774964431280.58144822M50.00000000296.985974881553.84576956M40.00000000819.246266641826.49875285M30.00000000−411.294521341414.13408128M20.00000000−1223.76315336879.35100849Stop0.00000000−1504.18673115497.47373340M10.00000000−1814.1230645826.60210356Object plane0.00000000 −1997.799732601636.55227043 TABLE 4b for FIG. 24/25SurfaceTLA [deg]TLB [deg]TLC [deg]Image plane−0.000000000.00000000−0.00000000M8−6.692737980.00000000−0.00000000M7166.949285750.00000000−0.00000000M666.320265540.00000000−0.00000000M541.577524090.00000000−0.00000000M4−66.849463650.00000000−0.00000000M326.188465260.00000000−0.00000000M244.254678740.00000000−0.00000000Stop7.97043789 0.00000000−0.00000000M1165.887862810.00000000−0.00000000Object plane−0.946825850.00000000−0.00000000 TABLE 5 for FIG. 24/25SurfaceAngle of incidence [deg]ReflectivityM86.807705620.66078858M70.468259460.66566251M678.951263820.86420515M576.473025230.82792785M44.688786930.66344392M382.649440000.91162945M279.541791920.87221922M120.658169810.60938007Overall transmission0.1012 TABLE 6 for FIG. 24/25X[mm]Y[mm]Z[mm]0.00000000−112.356890680.00000000−28.34197084−110.844440410.00000000−56.16590328−106.347817970.00000000−82.95239148−98.989550060.00000000−108.17910149−88.973627780.00000000−131.31951112−76.581712210.00000000−151.84357438−62.164313020.00000000−169.22272201−46.128059140.00000000−182.94128521−28.921881020.00000000−192.51547539−11.023555420.00000000−197.520038787.075013000.00000000−197.6212248524.885946800.00000000−192.6126370441.946728570.00000000−182.4480639657.840538530.00000000−167.2640270372.21001749−0.00000000−147.3865302584.76311384−0.00000000−123.3207062395.27376291−0.00000000−95.72644632103.57890521−0.00000000−65.38585433109.57098767−0.00000000−33.16868503113.18678340−0.00000000−0.00000000114.395091630.0000000033.16868503113.186783400.0000000065.38585433109.570987670.0000000095.72644632103.578905210.00000000123.3207062395.27376291−0.00000000147.3865302584.763113840.00000000167.2640270372.21001749−0.00000000182.4480639657.840538530.00000000192.6126370441.946728570.00000000197.6212248524.885946800.00000000197.520038787.075013000.00000000192.51547539−11.023555420.00000000182.94128521−28.921881020.00000000169.22272201−46.128059140.00000000151.84357438−62.16431302−0.00000000131.31951112−76.581712210.00000000108.17910149−88.973627780.0000000082.95239148−98.98955006−0.0000000056.16590328−106.347817970.0000000028.34197084−110.844440410.00000000 An overall reflectivity of the projection optical unit 36 is 10.11%. The projection optical unit 36 has an image-side numerical aperture of 0.50. The image field 8 has an x-extent of two times 13 mm and a y-extent of 1.20 mm. The projection optical unit 36 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The projection optical unit 36 has exactly eight mirrors M1 to M8. The mirrors M2 and M3 on the one hand, and M5, M6 on the other hand are embodied as mirrors for grazing incidence and are arranged in each case as a mirror pair directly behind one another in the imaging beam path. The projection optical unit 36 has exactly four mirrors for grazing incidence, namely the mirrors M2, M3, M5 and M6. The mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence. In the projection optical unit 36, a stop 18 is arranged in the beam path between the mirrors M1 and M2, near the grazing incidence on the mirror M2. Alternatively or additionally, a stop can be arranged directly on the surface of the mirror M2. An angle of incidence of the chief rays 16 in the object plane 5 is 6.7°. In the xz-plane (cf. FIG. 25), an entrance pupil of the projection optical unit 36 lies 2225 mm in front of the object field 4 in the beam path of the illumination light. In the yz-plane, the entrance pupil lies 4000 mm after the object field in the imaging beam path of the projection optical unit 36. An extent of the chief rays 16 emanating from the object field 4 is therefore convergent both in the meridional section according to FIG. 24 and in the view according to FIG. 25. The mirror M8 defines an image-side obscuration which is less than 18% of the image-side numerical aperture of the projection optical unit 36 in the x-dimension. In the xz-section (cf. FIG. 25), the stop 18 can lie at a position displaced in the z-direction compared to its position in the yz-section. A z-distance between the object field 4 and the image field 8 is approximately 1600 mm. An object/image offset (dOIS) is approximately 2000 mm. A free working distance between the mirror M7 and the image field 8 is 71 mm. In the projection optical unit 36, a scanned RMS value for the wavefront aberration is at most 11 mλ and, on average, 10 mλ. A maximum distortion value is at most 0.10 nm in the x-direction and at most 0.32 nm in the y-direction. A telecentricity value in the x-direction is at most 0.61 mrad on the image field-side and a telecentricity value in the y-direction is at most 0.74 mrad on the image field-side. Further mirror data emerge from the following table. TABLE 7 for FIG. 24/25M1M2M3M4M5M6M7M8Maximum angle of incidence [deg]21.383.284.36.278.681.915.18.3Mirror extent (x) [mm]337.8498.9706.6851.1595.2330.2321.8800.4Mirror extent (y) [mm]293.4499.9596.791.9262.9436.4205.1782.9Maximum mirror diameter [mm]337.9529.5807.8851.2595.3442.3321.9801.2 There is an intermediate image 19 in the beam path in the region between the mirrors M3 and M4 in the yz-plane (FIG. 24) and in the imaging beam path region between the mirrors M6 and M7 in the xz-plane (FIG. 25). The mirror M8 is obscured and includes a passage opening 17 for the passage of the illumination light 3 in the imaging beam path between the mirrors M6 and M7. Only the last mirror M8 in the imaging beam path includes a passage opening 17 for the imaging light 3. All other mirrors M1 to M7 have a continuous reflection surface. The reflection surface of the mirror M8 is used around the passage opening 17 thereof. The mirrors M1, M3, M4 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The other mirrors M2, M5, M6 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 for grazing incidence have very large radii and only constitute small deviations from plane reflection surfaces. A further embodiment of a projection optical unit 37, which can be used in the projection exposure apparatus 1 according to FIG. 1 instead of e.g. the projection optical unit 7, is explained in the following text on the basis of FIGS. 26 and 27. Components and functions which were already explained above in the context of FIGS. 1 to 25 are appropriately denoted by the same reference signs and are not discussed again in detail. FIG. 26 shows a meridional section of the projection optical unit 37. FIG. 27 shows a sagittal view of the projection optical unit 37. The projection optical unit 37 has a total of 8 mirrors M1 to M8 and, in terms of the basic design thereof, it is similar to e.g. the projection optical unit 7 according to FIG. 2. The projection optical unit 37 is embodied as anamorphic optical unit. In the yz-section according to FIG. 26, the projection optical unit 37 has a reducing imaging scale βy of 8.00. In the xz-plane (cf. FIG. 27) perpendicular thereto, the projection optical unit 37 has a reducing imaging scale βx of 4.00. These different imaging scales βx, βy lead to an object-side numerical aperture being half the size in the yz-plane compared to the xz-plane, as emerges immediately from comparison between FIGS. 26 and 27. As a result of this, an advantageously small chief ray angle CRAO of 3.6° is obtained in the yz-plane. The anamorphic effect of the projection optical unit 37 is distributed to all optical surfaces of the mirrors M1 to M8. The mirrors M1 to M8 are once again embodied as free-form surface mirrors, for which the free-form surface equation (1), specified above, applies. The optical design data from the projection optical unit 37 can be gathered from the following tables, which, in terms of their design, correspond to the tables for the projection optical unit 7 according to FIG. 2. TABLE 1 for FIG. 26/27Exemplary embodimentFIG. 26/27NA0.45Wavelength13.5nmField dimension x26.0mmField dimension y1.2mmField curvature0.0070851/mmStopS9 TABLE 2 for FIG. 26/27SurfaceRadius x[mm]Power x[1/mm]Radius y[mm]Power y[1/mm]OperatingM8−1175.113697490.00169070−952.265348540.00211425REFLM7−3724.820868850.00050451645.33108835−0.00329838REFLM64206.42425174−0.00010535—0.00001879REFLM529363.70859574−0.0000147510812.21558149−0.00085442REFLM4−2837.316132250.00069810−1775.438282120.00113745REFLM314646.09252672−0.0000245920193.39993088−0.00054992REFLM2−8591.259849620.00004428−35101.903033780.00029955REFLM1—0.00004251−3327.739360480.00063940REFL TABLE 3afor FIG. 26/27CoefficientM8M7M6KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX−1175.11369700−3724.820869004206.42425200C7 −1.45376933e−081.36379606e−07−7.10374101e−08C9 −1.22873208e−08−2.63387155e−08−3.11941218e−08C10 −2.1470539e−113.8586011e−10 −2.47199046e−10C12 −3.96186575e−115.63942817e−104.909512e−11C14 −1.98735779e−11 2.24402337e−09−4.82549835e−11C16 −1.30420456e−15 7.62990824e−138.40182189e−13C18 −6.32426869e−15 5.2611787e−12 −1.54721191e−13C20 −2.91618922e−14−8.64296247e−12−6.95092865e−14C21 −1.68020917e−171.79337812e−164.704138e−16C23 −6.25679388e−176.25344238e−15−1.98020462e−15C25 −8.80198872e−179.42589658e−152.8630395e−16C27 −2.15377736e−173.16333951e−15−7.77736805e−17C29 −4.600369e−208.50826753e−19−8.89962473e−19C31 −2.88783883e−202.46500403e−185.70734704e−18C33 −8.24469634e−206.11421542e−18−4.94608169e−19C35 2.99965283e−202.68054245e−16−5.37362862e−20C36 −9.14144609e−23−7.61482446e−22−1.16419356e−20C38 4.56746146e−23−2.10318024e−20−9.74634025e−21C40 −7.5942581e−23−5.13442867e−20−1.73898241e−20C42 −9.34952004e−23−3.80153592e−191.16341028e−21C44 8.70041492e−23−1.58149457e−18−5.56161657e−23C46 2.46539099e−251.26001421e−232.22991592e−23C48 8.63975279e−262.26904047e−22−1.33814512e−23C50 −4.64231072e−26−6.94971301e−222.69140707e−23C52 6.06567137e−26−6.14162469e−21−5.72930293e−24C54 −1.27628469e−25−1.39892604e−20−3.17383225e−26C55 2.6730632e−281.6124594e−262.37901686e−25C57 −4.04681746e−281.79194869e−265.74908171e−25C59 −6.13934671e−28−1.07916138e−245.16858652e−25C61 −6.82989222e−28−1.84874159e−242.29934781e−26C63 3.76587364e−295.28129065e−241.41744145e−26C65 −5.97299103e−284.17347416e−23−6.38021913e−28C67 −8.00678063e−31−1.43486698e−28−1.37565501e−27C69 −1.53299808e−30−1.07367054e−26−2.50594871e−27C71 −2.2827634e−30−5.11892322e−26−1.5202136e−27C73 −9.22430613e−315.3567633e−265.54122224e−29C75 −2.04873095e−315.18408279e−25−2.72156696e−30C77 −6.4177289e−325.33075313e−25−1.86793706e−30C78 −7.06113511e−34−2.43461881e−32−2.29557514e−30C80 1.65419247e−33−3.36354314e−30−3.59407598e−30C82 2.92887405e−33−5.11443547e−29−5.23025061e−30C84 2.38944422e−33−1.21605902e−28−1.39956581e−30C86 1.43540305e−333.51950254e−28−9.71779804e−31C88 −8.40166712e−341.05641088e−27−2.99362195e−32C90 2.0391317e−334.65391348e−28−5.23904991e−33C92 1.00499798e−36−8.58357662e−341.34776694e−32C94 4.02569735e−364.77402789e−324.44047422e−32C96 7.01500616e−364.67883986e−314.16406381e−32C98 8.04929982e−369.55009976e−311.04273961e−32C1004.68663927e−36−3.2932887e−301.93974596e−33C102−1.29112855e−37−1.71231238e−29−1.56753621e−34C1049.67137076e−37−7.97131674e−30−1.47926534e−37C1051.11271388e−39−3.44544264e−378.43323406e−36C107−4.76286158e−394.82999866e−36−3.41901443e−35C109−1.118952e−383.91182791e−34−8.08948161e−35C111−7.53155915e−392.39245204e−33−5.40349834e−35C1139.30385061e−402.7404568e−33−1.00364838e−35C1151.87013187e−39−2.89625364e−32−8.7229565e−37C1176.90121236e−40−5.01404328e−323.65273911e−37C119−3.74212372e−39−4.09799797e−321.12325475e−38C121−9.54707202e−4300C123−2.62679834e−4200C125−8.36961189e−42 00C127 −1.27197695e−41 00C129 −1.69138752e−41 00C131 −1.47039402e−41 00C133 −6.44328143e−43 00C135−1.4137325e−42 00C136 −6.29707457e−46 00C1387.90022937e−45 00C1401.78795966e−4400C1429.78046993e−46 00C144−2.43869352e−4400C146 −3.47062344e−44 00C148 −1.50798531e−44 00C1501.06161581e−4500C1521.98865409e−45 00 TABLE 3b for FIG. 26/27CoefficientM5M4M3KY0.000000000.000000000.00000000KX0.000000000.000000000.00000000RX29363.70860000−2837.31613200 14646.09253000C7 −4.08679454e−08−2.2313771e−08−2.40261236e−08C9 −8.36871827e−08−2.32045837e−07−2.73422915e−08C10 2.09705971e−123.04092615e−12−2.9513388e−11C12 2.51272222e−113.61049914e−11 −9.15077185e−12C14 1.69227063e−10−2.42492909e−102.00210463e−11C16 5.53060661e−16−2.0819334e−156.86342081e−15C18 −9.23199034e−15−7.74983288e−144.41510207e−16C20 −4.027388e−13−6.80249784e−13 −2.58531088e−14C21 −3.47291575e−182.26580114e−19−2.20608669e−18C23 −3.45747429e−172.377501e−17−2.05484907e−17C25 −7.65596175e−175.04278865e−16−3.59068158e−17C27 9.79386352e−16 7.19302412e−151.79584203e−16C29 2.90897557e−20−1.01345449e−21−6.1251551e−21C31 1.0408761e−19−1.71410922e−193.62781965e−20C33 4.42359728e−19−2.04391929e−181.22971099e−19C35 −2.18936205e−18−1.54712261e−161.94648572e−18C36 1.30619995e−23 1.43899323e−261.07492344e−23C38 −3.65876394e−23−3.4203498e−245.58625518e−23C40 −1.52815438e−22−7.30927606e−221.48075572e−22C42 −2.96583741e−21−1.1688423e−201.16917436e−21C44 5.7262241e−213.59003428e−18−5.57317878e−21C46 −1.6972836e−251.14473368e−27 −6.48101479e−28C48 −4.74294826e−255.43217288e−26 −4.63479637e−25C50 −7.95753522e−25−1.137132e−23−2.24743327e−24C52 −3.26107419e−24−4.83879624e−22−4.28781689e−24C54 −2.26528951e−234.56671842e−20 −1.67533641e−22C55 −4.30900642e−295.10227319e−31 −1.05264632e−28C57 2.89748678e−285.65706438e−29−1.05218012e−28C59 2.11195041e−274.28804717e−27 −1.31683082e−27C61 5.0160429e−271.38412296e−24 −1.05261953e−26C63 7.19967176e−26−9.83289711e−24−3.85154123e−26C65 −4.08256809e−26−1.6982784e−21 −4.65379054e−25C67 5.05025434e−31−6.95990045e−33−3.11256872e−32C69 1.42714944e−30−1.33890648e−30 1.65988582e−30C71 7.45092588e−30−5.83117347e−29 1.56036122e−29C73 1.99335578e−29−2.28709957e−26 7.80549941e−29C75 6.23811627e−282.13086029e−256.62602459e−29C77 −2.27266233e−289.58109313e−243.88182163e−27C78 5.21616902e−35−2.18826289e−37 2.25858762e−34C80 −3.89851427e−342.51802019e−351.96804001e−35C82 −6.6719409e−336.15191756e−347.16915829e−33C84 2.59908145e−32−1.57558885e−30 8.22440794e−32C86 −2.38366597e−311.52473073e−283.31913873e−31C88 −6.81072162e−312.46751442e−275.7378916e−31C90 2.30360439e−307.51106446e−262.96813954e−29C92 −8.0899315e−376.76836149e−394.61223413e−38C94 −9.2704549e−361.45298999e−36−2.33835226e−36C96 −6.4688252e−351.62712528e−34 −3.24259664e−35C98 −9.76323269e−353.29916833e−32−2.83361995e−34C100−1.72013015e−33−5.56840797e−31−9.31180311e−34C102−1.4852411e−32−5.59819448e−29−1.23445076e−34C1041.76323714e−32−9.11469106e−287.59914928e−32C1052.70851366e−41−3.10685744e−43−1.38859727e−40C1072.70717847e−39−1.41829562e−404.12766595e−40C1094.3484992e−38−9.43723768e−39−1.19038711e−38C1117.71332614e−38−1.1727652e−36−2.06952102e−37C1133.20979484e−37−1.56794917e−34−1.38822649e−36C115−2.94924599e−361.70010457e−33−3.67358357e−36C117−3.38333116e−352.40858822e−31−2.35890929e−36C1195.46219248e−352.39253918e−307.02180934e−35 TABLE 3c for FIG. 26/27CoefficientM2M1KY0.000000000.00000000KX0.000000000.00000000RX−8591.25985000−44223.29270000C7 2.99148093e−08−3.51511776e−08C9 −2.75260874e−09−7.11448809e−08C10 5.55081545e−11−4.10270779e−11C12 −5.97183171e−12−2.8217723e−11C14 −4.06031762e−132.14989264e−10C16 −2.79778356e−141.40795276e−13C18 1.79288323e−148.05770554e−13C20 −3.38327995e−15−2.59389473e−13C21 −3.48066202e−174.10045555e−17C23 1.63939639e−17−7.17948803e−16C25 1.84526437e−18−1.3131289e−15C27 −1.02528315e−182.72912338e−16C29 −1.3014589e−19−4.68210382e−20C31 −5.87409678e−211.02547618e−19C33 −1.16533212e−20−3.15126138e−18C35 5.34922803e−21−3.27597939e−18C36 5.03657859e−223.82370931e−23C38 −1.91027438e−221.12562095e−21C40 −7.7852516e−238.84579475e−21C42 −1.1265141e−236.72624215e−20C44 −6.20839372e−25−2.03858478e−20C46 −2.10802913e−253.84408406e−24C48 2.31729842e−254.44222408e−23C50 5.57599755e−26−2.10654686e−23C52 7.03833262e−28−3.99067489e−22C54 −1.44691171e−26−4.82876579e−22C55 −5.4662909e−28−5.75573129e−29C57 7.13770069e−281.05708712e−26C59 9.05959984e−284.45669379e−26C61 3.90484003e−28−3.24661836e−27C63 2.9845833e−29 −1.59551772e−24C65 −2.62761246e−304.84788324e−24C67 7.20493267e−31−2.6429913e−29C69 −1.50894693e−30−9.20367529e−28C71 −9.91502164e−31−4.32416568e−27C73 −1.90214439e−311.34332393e−27C75 2.61487275e−322.39717536e−26C77 2.34033428e−322.51255795e−26C78 −2.16847329e−33−8.54089655e−33C80 −3.95387479e−33−1.24782323e−31C82 −5.79159657e−331.15198274e−30C84 −3.51740059e−337.37679351e−30C86 −9.22238958e−34−4.65048215e−30C88 −3.05983814e−35−6.03530894e−30C90 9.8645578e−36 −1.90490163e−28C92 1.31596904e−362.57330157e−35C94 7.63172154e−362.82127945e−33C96 4.69550164e−362.41325577e−32C98 1.33696127e−366.70244162e−32C1001.54304009e−37−8.05861336e−32C102−3.22616636e−38−4.38796518e−31C104−1.43000965e−38−2.82969243e−31C1058.01929474e−403.73241981e−38C1073.2676891e−39 1.45855716e−36C1097.46821996e−393.02629332e−36C1119.81393372e−39−3.70759447e−35C1134.50117184e−39−1.1474833e−34C1157.30739397e−405.05238578e−34C1171.09045016e−421.19088272e−33C119−8.75346337e−423.36419998e−33 TABLE 4a for FIG. 26/27SurfaceDCXDCYDCZImage plane0.000000000.000000000.00000000M80.000000000.00000000859.88832187M70.00000000−176.20561941108.16423659M60.00000000−698.544394411140.58633390M5−0.00000000−716.554003011977.10005031M40.00000000−472.437921402531.29159348M30.00000000−1379.512663571438.63634577M20.00000000−2608.29927284741.99389453Stop0.00000000−2918.25887054352.59739373M10.00000000−3267.93714103−86.69693993Object plane0.00000000−3324.460148802242.98343748 TABLE 4b for FIG. 26/27SurfaceTLA [deg]TLB [deg]TLC [deg]Image plane−0.000000000.00000000−0.00000000M8−6.596038220.00000000−0.00000000M7186.822191040.00000000−0.00000000M6104.03490485 −0.00000000 0.00000000M578.73015909−0.00000000−0.00000000M4−31.735505730.00000000−0.00000000M3219.92622552−0.00000000−0.00000000M240.515320740.00000000−0.00000000Stop19.04239581180.000000000.00000000M1161.43502849−0.00000000−0.00000000Object plane−2.211671350.00000000−0.00000000 TABLE 5 for FIG. 26/27SurfaceAngle of incidence [deg]ReflectivityM86.596038220.66110189M720.014267480.61355760M677.198446330.83904083M577.496807910.84348513M47.962472720.65888448M379.624203970.87332138M279.035108740.86535589M119.954816480.61393176Overall transmission0.0878 TABLE 6 for FIG. 26/27X[mm]Y[mm]Z[mm]0.00000000−219.156462590.0000000046.68638707−216.357035080.0000000092.44920291−208.039526480.00000000136.36850701−194.430931480.00000000177.53246672−175.881406500.00000000215.04126471−152.864533450.00000000248.01037220−125.995178180.00000000275.57900231−96.033964980.00000000296.93376542−63.857468540.00000000311.35383746−30.389631210.00000000318.270035443.492905510.00000000317.3166727437.053063250.00000000308.3562088169.734676890.00000000291.47003488101.089009870.00000000266.93645742130.636670710.00000000235.22482493157.787916280.00000000197.00574657181.830555960.00000000153.16053621201.928152480.00000000104.79070426217.172466340.0000000053.22556587226.719031680.000000000.00000000229.97244838−0.00000000−53.22556587226.719031680.00000000−104.79070426217.172466340.00000000−153.16053621201.92815248−0.00000000−197.00574657181.830555960.00000000−235.22482493157.787916280.00000000−266.93645742130.636670710.00000000−291.47003488101.089009870.00000000−308.3562088169.734676890.00000000−317.3166727437.053063250.00000000−318.270035443.492905510.00000000−311.35383746−30.389631210.00000000−296.93376542−63.857468540.00000000−275.57900231−96.033964980.00000000−248.01037220−125.995178180.00000000−215.04126471−152.864533450.00000000−177.53246672−175.881406500.00000000−136.36850701−194.430931480.00000000−92.44920291−208.039526480.00000000−46.68638707−216.357035080.00000000 An overall reflectivity of the projection optical unit 37 is 8.78%. The projection optical unit 37 has an image-side numerical aperture of 0.45. The image field 8 has an x-extent of two times 13 mm and a y-extent of 1.20 mm. The projection optical unit 37 is optimized for an operating wavelength of the illumination light 3 of 13.5 nm. The projection optical unit 37 has exactly eight mirrors M1 to M8. The mirrors M2 and M3 on the one hand, and M5, M6 on the other hand are embodied as mirrors for grazing incidence and are arranged in each case as a mirror pair directly behind one another in the imaging beam path. The mirrors M2 and M3 deflect the chief rays 16 in opposite directions in the xy-plane. The projection optical unit 37 has exactly four mirrors for grazing incidence, namely the mirrors M2, M3, M5 and M6. The mirrors M1, M4, M7 and M8 are embodied as mirrors for normal incidence. In the projection optical unit 37, a stop 18 is arranged in the beam path between the mirrors M1 and M2, near the grazing incidence on the mirror M2. Alternatively or additionally, a stop can be arranged directly on the surface of the mirror M2. In the xz-plane (cf. FIG. 27), an entrance pupil of the projection optical unit 37 lies 3000 mm after the object field 4 in the beam path of the illumination light. In the yz-plane, the entrance pupil lies 3100 mm after the object field in the imaging beam path of the projection optical unit 37. An extent of the chief rays 16 emanating from the object field 4 is therefore convergent both in the meridional section according to FIG. 26 and in the view according to FIG. 27. In the xz-section (cf. FIG. 27), the stop 18 can lie at a position displaced in the z-direction compared to its position in the yz-section. A z-distance between the object field 4 and the image field 8 is approximately 2100 mm. An object/image offset (dOIS) is approximately 3400 mm. A free working distance between the mirror M7 and the image field 8 is 86 mm. In the projection optical unit 37, a scanned RMS value for the wavefront aberration is at most 18 mλ and, on average, 14 mλ. A maximum distortion value is at most 0.15 nm in the x-direction and at most 0.14 nm in the y-direction. A telecentricity value in the x-direction is at most 1.17 mrad on the image field-side and a telecentricity value in the y-direction is at most 2.77 mrad on the image field-side. Further mirror data emerge from the following table. TABLE 7 for FIG. 26/27M1M2M3M4M5M6M7M8Maximum angle of incidence [deg]21.381.783.18.878.780.331.68.5Mirror extent (x) [mm]548.7753.91041.91335.9970.3391.0475.7814.4Mirror extent (y) [mm]282.81204.8373.1115.5344.4626.7219.4791.0Maximum mirror diameter [mm]548.71204.81042.01336.0970.3628.1475.8815.2 There is an intermediate image 19 in the beam path in the region of a reflection on the mirror M3 in the yz-plane (FIG. 26) and in the imaging beam path region between the mirrors M6 and M7 parallel to the xz-plane (FIG. 27). The last mirror M8 in the beam path is not obscured. The illumination light 3 is guided past the continuously used mirror M8 in the partial beam path between the mirrors M6 and M7. All mirrors M1 to M8 have a continuously used reflection surface. The mirrors M1, M2, M4, M6 and M8 have negative values for the radius, i.e. are, in principle, concave mirrors. The other mirrors M3, M5 and M7 have positive values for the radius, i.e. are, in principle, convex mirrors. The mirrors M2, M3, M5 and M6 for grazing incidence have very large radii and only constitute small deviations from plane reflection surfaces. Some of the data of the above-described projection optical units are once again summarized in the following Tables I and II. The respective first column serves to assign the data to the respective exemplary embodiment. The following Table I summarizes the following optical parameters: numerical aperture (NA), image field extent in the x-direction (Fieldsize X), image field extent in the y-direction (Fieldsize Y), image field curvature (Field Curvature) and overall reflectivity or system transmission (Transmission). The following Table II specifies the following parameters: “order of the mirror types” (Mirror Type Order), “order of the mirror deflection effect” (Mirror Rotation Order), “refractive power order in the xz-plane” (x Power Order) and “refractive power order in the yz-plane” (y Power Order). These sequences in each case start with the last mirror in the beam path, i.e. follow the reverse beam direction. By way of example, the sequence “L0RRLLLR” relates to the deflection effect in the sequence M8 to M1 in the embodiment according to FIG. 2. TABLE 1FIELDFIELDSIZEFIELDSIZECURVA-XYTURETRANSMIS-FIG.NA[mm][mm][1/mm]SION %20.45130.784010.4330.45130.95013.0940.45130.72013.3250.45130.98014.7360.45130.78408.1170.45130.78409.8880.45130.784010.0490.45130.78408.8310 0.45130.78407.8914, 150.6131.20.049314558.6716, 170.63131.209.9518, 190.55131.2010.0320, 210.55261.2010.1722, 230.49261.6010.1524, 250.5261.2010.1226, 270.45261.20.00708558.78 TABLE 2MIRRORMIRRORROTATIONx POWERy POWERFIG.TYPE ORDERORDERORDERORDER2NNGGNGGNL0RRLLLR+−−++++−+−−++−++3NNNNGG00RLLL+−−−+++−−+−+4NNNNGGR0RRRR+−−++++−−+−+5NNNNGGG00RLRLR+−−+−−++−−+−−+6NNGGNGGNRRLRRLRL+−−+++−++−−++−−+7NNGGNGGNR0LRRLRL+−−++++++−+−++−+8NNGGNGGNR0RLRLRL+−−++−+++−−+++−+9NNGGNGGNR0LLRRRL+−+−+−−++−−−+−++10 NNGGNGGNGR0LLRRRLL+−+−+−−+−+−−−+−++−14, 15NNGGNGGNLRRRLLLR+−−++++−+−+−++−+16, 17NNGGNGGNLRRRLLLR+−−−+++−+−−−++−+18, 19NNGGNGGNL0RRLLLR+−−−+++−+−−−++−+20, 21NNGGNGGNL0RRLLLR+−−−+++++−−−++−+22, 23NNGGNGGNL0RRLLLR+−−−+++++−−+++−+24, 25NNGGNGGNL0RRLLLR+−−−+++++−−−++−+26, 27NNGGNGGNLRRRLRLR++−−+−+++−+−+−++ In the mirror type, the specification “N” relates to a normal incidence (NI) mirror and the designation “G” relates to a grazing incidence (GI) mirror. In the refractive power orders, “+” denotes a concave mirror surface and “−” denotes a convex mirror surface. When comparing the refractive power orders in x and y, it is possible to see that practically all exemplary embodiments, with the exception of e.g. the embodiment according to FIG. 5, have different refractive power orders in x and y. By way of example, the mirror M1 of the embodiment according to FIG. 2 is convex (refractive power “−”, negative refractive power) in the x-direction and concave (refractive power “+”, positive refractive power) in the y-direction. These mirrors with different signs of the refractive power in x and y constitute saddle surfaces. With the exception of the embodiments according to FIGS. 5 and 10, GI mirrors always occur in pairs, as can be gathered from the order of the mirror types in Table II. In the embodiment according to FIG. 5, three GI mirrors lie one behind the other, namely the mirrors M1 to M3. In the embodiment according to FIG. 10, there is a single GI mirror, namely the mirror M1. The orders of the mirror types of the embodiments according to FIGS. 6 to 9 and 14 to 27 are identically NNGGNGGN for mirrors M8 to M1. The embodiments according to FIGS. 14 to 17 and 27 have an identical deflection effect order, namely LRRRLLLR, for mirrors M8 to M1. The embodiments according to FIGS. 18 to 25 in turn have an identical deflection effect order, namely L0RRLLLR, for mirrors M8 to M1. In respect of the refractive power order, the embodiment according to FIG. 7 has five successive mirrors with positive refractive power in the xz-plane, namely mirrors M1 to M5. Other embodiments have up to four successive mirrors with positive refractive power in the xz-plane. The embodiments according to FIGS. 8 and 22 have three mirrors arranged behind one another with in each case a positive refractive power in the yz-plane, namely mirrors M3 to M5 in each case. The other exemplary embodiments, the design data of which were discussed above, do not have more than two successive mirrors with positive refractive power in the yz-plane. A plurality of embodiments of the above-described projection optical units do not have two successive mirrors with positive refractive power in either the xz-plane or in the yz-plane. The embodiment according to FIG. 5 does not have two successive mirrors with positive refractive power in both planes xz and yz. In order to produce a microstructured or nanostructured component, the projection exposure apparatus 1 is used as follows: initially, the reflection mask 10 or the reticle and the substrate or the wafer 11 are provided. Subsequently, a structure on the reticle 10 is projected onto a light-sensitive layer of the wafer 11 with the aid of the projection exposure apparatus 1. By developing the light-sensitive layer, a microstructure or nanostructure is then generated on the wafer 11, and hence the microstructured component is generated.
	abstract	An irradiation apparatus has a large irradiation field and is capable of ensuring the uniformity of a dose distribution without strengthening the performance of an irradiation field enlarging device. The irradiation apparatus includes a beam interruption part for performing a plurality of irradiations of a radiation beam, a position control part for controlling a location to be irradiated in such a manner that the entire surface of the target can be irradiated in a plurality of irradiation zones including an overlapping area formed by the plurality of irradiations, and a multileaf collimator control part for providing a slope to a dose distribution in the overlapping area of the respective irradiation zones, so that the dose distribution over the entire surface of the target including the overlapping area is made flat or uniform by the plurality of irradiations of the radiation beam.
	abstract	A method and apparatus for a boiling water reactor (BWR) jet pump inlet mixer compliant stop. The inlet mixer compliant stop may be installed in a pocket area between a riser pipe and an inlet mixer of a BWR jet pump assembly. The inlet mixer compliant stop includes a main body and a foot that are separated via the tightening of one or more jacking bolts used to connect the main body and the foot. A cold spring attached to the main body provides a lateral force that is imparted on the inlet mixer, to force the inlet mixer away from a centerline of the riser pipe. A precise lateral force may be imparted on the inlet mixer by gauging a width of a gap between opposing bosses on a front face of the main body and a distal end of the cold spring. The inlet mixer compliant stop imparts a greater lateral force on the inlet mixer as the jacking bolts are tightened, further separating the main body from the foot, as the gap between the opposing bosses is reduced.
	abstract	In each of a number of fuel assemblies loaded in a core of a boiling water reactor, a fuel holding portion of a lower tie plate holds lower end portions a plurality of fuel rods and at least one water rod. The water rod includes a rising pipe opened to a space in the lower tie plate below the fuel holding portion and introducing upward a coolant introduced to the rising pipe, and a falling pipe communicated with the rising pipe and introducing downward the coolant introduced through the rising pipe. The falling pipe has a coolant outlet opened to a second coolant passage defined between the fuel rods above the fuel holding portion. The rising passage is filled with the coolant during a period of rated power operation of the reactor, and a surface of the coolant is formed in the rising pipe during a period of non-rated power operation in which a flow rate of the coolant supplied to the fuel assemblies is lower than that during the period of rated power operation. As a result, influences of a transient event during the rated power operation can be suppressed, and the nuclear thermal-hydraulic stability of the core during the non-rated power operation can be improved.
	abstract	In an in-core fixed nuclear instrumentation system for a reactor, each of a plurality of in-core nuclear instrumentation assemblies has a nuclear instrumentation tube. LPRM detectors are housed in the nuclear instrumentation tube for detecting LPRM signal in a core of the reactor. A GT assembly is housed in the tube. The GT assembly has fixed GT detectors for detecting xcex3-ray heating values and a built-in heater therein for calibrating the fixed GT detectors. The fixed GT detectors are arranged at least close to the fixed LPRM detectors, respectively. GT signals by the detected xcex3-ray heating values of the fixed GT detectors of each GT assemblies are processed by a GT signal processing unit. The heater in each GT assemblies is electrically energized by a GT heater control unit. Predetermined time intervals are stored in a memory unit. One of the predetermined time intervals for specified xcex3-ray thermometer assemblies, respectively is selected so that the GT heater control unit controls an electrical energy supplied to the heater by the selected interval so as to heat the heater, thereby executing a heater calibration of output voltage sensitivities of the fixed GT detectors of the GT assembly.
047524332	summary	BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to pressurized water reactor systems and, more particularly, to a vent system and method of operation for controlling and actuating hydraulically operated displacer rod drive mechanisms for selective positioning of water displacer rods in the reactor vessel. 2. State of the Relevant Art As is well known in the art, conventional pressurized water reactors employ a number of control rods which are mounted within the reactor vessel, generally in parallel axial relationship, for axial translational movement in telescoping relationship with the fuel rod assemblies. The control rods contain materials known as poisons, which absorb neutrons and thereby lower the neutron flux level within the core. Adjusting the positions of the control rods relative to the respectively associated fuel rod assemblies thereby controls and regulates the reactivity and correspondingly the power output level of the reactor. Typically, the control rods, or rodlets, are arranged in clusters, and the rods of each cluster are mounted to a common, respectively associated spider. Each spider, in turn, is connected to a respectively associated adjustment mechanism for raising or lowering the associated rod cluster. In certain advanced designs of such pressurized water reactors, there are employed both reactor control rod clusters (RCC) and water displacer rod clusters (WDRC). In one such reactor design, a total of over 2800 reactor control rods and water displacer rods are arranged in 185 clusters, each of the rod clusters being mounted to a respectively corresponding spider. In the exemplary such advanced design pressurized water reactor, there are provided, at successsively higher, axially aligned elevations within the reactor pressure vessel, a lower barrel assembly, an inner barrel assembly, and a calandria, each of generally cylindrical configuration, and an upper closure dome, or head. The lower barrel assembly may be conventional, having mounted therein, in parallel axial relationship, a plurality of fuel rod assemblies which are supported at the lower and upper ends thereof, respectively, by corresponding lower and upper core plates. Within the inner barrel assembly there is provided a large number of rod guides disposed in closely spaced relationship, in an array extending substantially throughout the cross-sectional area of the inner barrel assembly. The rod guides are of first and second types, respectively housing therewithin reactor control rod clusters (RCC) and water displacer rod clusters (WDRC); these clusters, as received in telescoping relationship within their respectively associated guides, generally are aligned with respectively associated fuel rod assemblies. One of the main objectives of the advanced design, pressurized water reactors to which the present invention is directed, is to achieve a significant improvement in the fuel utilization efficiency, resulting in lower, overall fuel costs. Consistent with this objective, the water displacement rodlet clusters (WDRC's) function as a mechanical moderator control, all of the WDRC's being fully inserted into association with the fuel rod assemblies, and thus into the reactor core, when initiating a new fuel cycle. Typically, a fuel cycle is of approximately 18 months, following which the fuel must be replaced. As the excess reactivity level diminishes over the cycle, the WDRC's are progressively, in groups, withdrawn from the core so as to enable the reactor to maintain the same reactivity level, even though the reactivity level of the fuel rod assemblies is reducing due to dissipation over time. Conversely, the control rod clusters are moved, again in axial translation and thus telescoping relationship relatively to the respectively associated fuel rod assemblies, for control of the reactivity and correspondingly the power output level of the reactor on a continuing basis, for example in response to load demands, in a manner analogous to conventional reactor control operations. The calandria includes a lower calandria plate and an upper calandria plate. The rod guides are secured in position at the lower and upper ends thereof, respectively, to the upper core plate and the lower calandria plate. Within the calandria and extending between the lower and upper plates thereof is mounted a plurality of calandria tubes in parallel axial relationship, respectively aligned with the rod guides. Flow holes are provided in remaining portions of the calandria plates, intermediate the calandria tubes, through which passes the reactor core outlet flow as it exits from its upward passage through the inner barrel assembly. The core outlet flow, or a major portion thereof, turns from the axial flow direction to a radial direction for passage through radially outwardly oriented outlet nozzles which are in fluid communication with the calandria. In similar, parallel axial and aligned relationship, the calandria tubes are joined to corresponding flow shrouds which extend to a predetermined elevation within the head, and which in turn are connected to corresponding head extensions which pass through the structural wall of the head and carry, on their free ends at the exterior of and vertically above the head, corresponding adjustment mechanisms, as above noted. The adjustment mechanisms have corresponding control shafts, or drive rods, which extend through the respective head extensions, flow shrouds, and calandria tubes and are connected to the respectively associated spiders mounting the clusters of RCC rods and WDRC rods, and serve to adjust their elevational positions within the inner barrel assembly and, correspondingly, the level to which the rods are lowered into the lower barrel assembly and thus into association with the fuel rod assemblies therein, thereby to control the activity within the core. In the exemplary, advanced design pressurized water reactor, over 2,800 rods are mounted in 185 clusters, the latter being received within corresponding 185 rod guides. Of these clusters, 88 are of the WDRC type, divided into 22 groups of four clusters each, the clusters of each group being chosen such that withdrawal of an individual group, or multiple such groups, maintains a symmetrical power distribution within the reactor core. Since each WDRC is approximately 700 lbs. to 800 lbs. in weight, each group of four (4) such clusters presents a combined weight of in the range of from 2,800 lbs. to 3,200 lbs., requiring that a drive mechanism and associated connecting structure for each group of four clusters have substantial strength and durability, and afford a substantial driving force. Due to the packing density, or close spacing, of the rod clusters and their associated guides, severe spacing requirements are imposed, both within the vessel and with respect to the rod drive mechanisms, including both the water displacer rod drive mechanisms (DRDM's) and the control rod drive mechanism (CRDM's). The critical spacing requirements were not experienced in reactors of prior, conventional types, which did not employ WDRC's and correspondingly did not employ DRDM's. In reactors of such conventional designs, ample spacing was available above the dome, or head, of the vessel for accommodating the required number of mechanisms for driving the RCC's. Particularly, the CRDM's of well known, electromechanical type associated with corresponding clusters of RCC's, were mounted in generally parallel axial relationship, vertically above the dome or head of the vessel and extended in sealed relationship through the head for connection by suitable drive rods to the associated RCC's, and provided for selectively controlled gradual raising and lowering of the RCC's for moderating the reactor energy level, or for rapidly lowering same in the case of shutdown requirements. In reactor systems of the advanced design herein contemplated, whereas the same mechanisms conventionally employed for the CRDM's functionally are acceptable for adjusting the WDRC's, due to the increased number of rod clusters (i.e., the total of RCC's and WDRC's), the conventional CRDM's are unacceptable mechanically, since they are too large. Various alternative mechanisms have been studied in view of this problem. For example, roller nut-drives were considered, but were determined to produce insufficient lifting force. Accordingly, a substitute DRDM has been developed which utilizes a hydraulically operated piston which is attached through a corresponding drive rod to each group of associated WDRC's, and which mechanism satisfies the spacing limitations, permitting mounting thereof above the head or dome of the vessel in conjunction with the conventional CRDM's. An example of such a hydraulically operated drive mechanism for a WDRC is shown in U.S. Pat. No. 4,439,054--Veronesi, issued Mar. 27, 1984 and assigned to the common assignee hereof. The provision of the hydraulically operated mechanism suitable for use with WDRC's as hereinabove set forth, however, has imposed a design requirement of a system to control and manipulate the hydraulic mechanism. No known systems are available for this purpose, in view of the fact that the requirement therefor has arisen out of the evolving design of the advanced design, pressurized water reactors of the type herein contemplated. SUMMARY OF THE INVENTION As before noted, a pressurized water nuclear reactor, of the advanced design type with which the vent system of the present invention is intended for use, employs a large number of reactor control rods, or rodlets, typically arranged in what are termed reactor control rod clusters (RCC) and, additionally, a large number of water displacer rods, or rodlets, similarly arranged in water displacer rod clusters (WDRC), an array of 185 such clusters containing a total of 2800 rodlets (i.e., the total of reactor control rods and water displacer rods) being mounted in parallel axial relationship within the inner barrel assembly of the reactor pressure vessel. The rods of each cluster are mounted at their upper ends to a corresponding spider, and the spider-mounted cluster is received in telescoping relationship within a corresponding rod guide. Each spider is connected through a drive rod to a corresponding adjustment mechanism, which provides for selectively raising or lowering the rod cluster relatively to an associated group of fuel rod assemblies. The adjustment mechanisms more specifically are mounted in generally parallel axial relationship on the head, or dome, of the pressure vessel. The control rod cluster drive mechanism (CRDM's) may be of conventional type as employed in the prior art, comprising electromechanically actuated mechanisms which provide for selectively raising and lowering the RCC's to provide the desired level of reactivity within the core and, alternatively, to lower the control rods rapidly in the event of a requirement for rapid shutdown. The drive mechanisms (DRDM's) for the water displacer rod clusters (WDRC's) may be of the type shown in the above referenced U.S. Pat. No. 4,439,054, which are driven hydraulically, and include a latch mechanism which mechanically latches at a fixed position adjacent the upper end of the stroke. The hydraulic mechanisms of the patented type are compatible in physical size with the CRDM's, and thus may be accommodated within the available spacings on the head, or dome, of the vessel. Each spider, and thus its associated vane assemblies, must be of considerable structural strength and weight. A typical water displacer rod (WDRC) cluster may comprise up to 24 water displacer rods mounted in alternating groups of two and four rods on corresponding ones of a total of eight vane assemblies, each of the four-rod assemblies including both a radially extending vane element and a pair of transversely extending vane elements, the latter carrying the cylindrical support mounts at their outer extremeties. As before noted, the total weight of a water displacer rod cluster, thus configured, is approximately 700 lbs. to 800 lbs. The spiders must support not only the dead weight of the respective rod clusters, but additionally must accommodate the forces imposed thereon both by the environment of the relatively fast-moving core outlet flow which passes thereover and the rod height adjustment functions. The total of eighty-eight (88) WDRC's, in the exemplary vessel, are divided into 22 groups of four clusters each, the WDRC's of each group being selected such that withdrawal of a given one or more of the WDRC groups maintains a symmetrical power distribution within the reactor core. It follows that the total weight of a WDRC group is substantial, ranging from 2,800 lbs. to 3,200 lbs., and that a correspondingly high level force must be developed for raising the WDRC groups, as required, at successive stages of the fuel cycle. The vent system for the displacer rod drive mechanisms (DRDM's) of a pressurized water reactor in accordance with the present invention comprises an arrangement of valves, flow restricting devices, and a common orifice, for hydraulically actuating the DRDM's to drive the WDRC's between either the fully inserted or fully withdrawn positions, relative to the fuel assemblies. The pressure differential between the reactor vessel and the reactor coolant drain tank, which acts on the DRDM's, is used to achieve this function. The common orifice regulates the flow level, as may be required when two or more WDRC groups are selected for simultaneous withdrawal operations. The common orifice, in conjunction with the individual flow restricting devices, thus limit the rate of travel of the WDRC's to a safe value. The vent system is selectively operable in three modes, or flow conditions, including (I) normal withdrawal, (II) normal insertion, and (III) withdrawal employing a bypass line. By selective operation of the valve arrangement and through use of the flow restricting devices in condition (I), the pressure within the vessel head produces a pressure differential within the selected hydraulic mechanisms for withdrawing the corresponding WDRC's. When the WDRC's are fully withdrawn, the corresponding valves are closed and the pressure differential across the hydraulic mechanisms dissipates, due to a designed rate of leakage past the piston rings therein. Once pressure equilibrium is established, the WDRC's drop, or descend, by force of gravity, automatically engaging the mechanical latches within the DRDM's which then lock the WDRC's in their withdrawn, parked positions. Insertion of one or more WDRC groups into the core from a fully withdrawn and locked position is achieved by initially establishing the valve actuation of condition (I) for the withdrawal operation for a limited interval, sufficent to permit the hydraulic mechanisms to advance upwardly and release the mechanical latches, following which, condition (II) is initiated, in which a further valve is opened to communicate pressure from a head vent of the vessel to the respective hydraulic mechanisms (DRDM's) of the selected group or groups, thereby equalizing the pressure across the corresponding pistons and allowing the WDRC's of each group to descend, or fall, into the core under the force of gravity. The withdrawal using bypass, of condition (III) of the vent system, accommodates certain abnormal operating conditions, such as when a drive rod is stuck or a set of high leakage piston rings fails to seat properly, which in turn may prevent one or more WDRC clusters from being withdrawn under the normal withdrawal procedure of condition (I). The bypass mode serves to bypass the previously noted, common orifice, thereby increasing the pressure drop across the DRDM piston rings by several hundred pounds per square inch (psi), the increased pressure differential thus imposed being sufficient to seat any malfunctioning piston ring and raise the WDRC group to the desired, fully withdrawn position. This operation concludes, as in the normal withdrawal step, with closing of the associated valves, permitting the WDRC's to settle into the parked position, engaged by the mechanical latch of the DRDM's. Additionally, the vent system of the invention provides a recovery procedure for correcting any missequencing of the drive operations which may occur either due to unexpected impediments, as above described, or as may arise from inadvertent, premature actuation of the valves causing one or more of the individual DRDM's of a given group to be latched in the parked, fully withdrawn position, while others remain in an intermediate position, neither fully withdrawn nor fully inserted. Accordingly, the vent system of the present invention provides efficient and effective operation, utilizing the available hydraulic driving force of the high pressure within the reactor vessel, while employing a minimum number of selectively actuated conventional valves and flow restricting devices in combination with the noted, hydraulically actuated DRDM's, to afford a system which is safe and versatile in operation, yet low in cost of components and operation. These and other advantages of the present invention will become more apparent from the following detailed drawings and associated discussion.
048204781	abstract	A control rod for use in a nuclear reactor core to provide xenon compensation includes an elongated inner cylindrical member and an elongated outer cylindrical member surrounding the inner member. Each of the members is composed of axially-extending, alternating black poison and nonpoison regions. Also, the inner member is axially movable relative to the outer member to adjust the degree to which the poison regions of the members overlap with the nonpoison regions thereof and thereby change the overall worth of the rod in an axially uniform manner. The inner cylindrical member has a solid cross-sectional configuration, whereas the outer cylindrical member has an annular cross-sectional configuration and concentrically surrounds the inner member. Each of the poison regions in the members is about the same axial height, while each of the nonpoison regions is about the same axial height. The guide thimble of a fuel assembly in which the control rod is placed has an annular stop being sized to support a lower end of the outer member for retaining the outer member in a stationary position therein, whereas the stop has a central hole sized to allow passage of a lower end of the inner member therethrough in order to move the inner member axially relative to the outer member to adjust the degree to which the poison regions of the members overlap with the nonpoison regions thereof and thereby change the overall worth of the rod.
	description	This nonprovisional application is a continuation of International Application No. PCT/EP2006/002252, which was filed on Mar. 10, 2006, and which claims priority to German Patent Application No. DE 102005011467, which was filed in Germany on Mar. 12, 2005, and which are both herein incorporated by reference. 1. Field of the Invention The present invention relates to a collimator having an adjustable focal length, particularly in X-ray inspection systems. 2. Description of the Background Art Inspection processes using X-rays are used for the detection of critical substances and objects in pieces of luggage or other freight. To this end, multi-stage systems are known whose first stage is based on the absorption of X-rays. For the detection of certain critical substances, such as explosives for example, a second stage is used, with objects from the first stage being selectively delivered thereto. Systems whose operating principle is based on diffraction phenomena are used as the second stage. In this connection, the diffraction angle at which an incident X-ray beam is diffracted depends on the atomic lattice spacing of the material to be inspected as well as on the energy, and thus the wavelength, of the incident radiation. Conclusions can be drawn concerning the lattice spacing and thus the material through analysis of the diffraction phenomena by means of X-ray detectors. Such a two-stage system is disclosed in German patent application 103 30 521.1, for example. Since X-ray inspection systems operate with extremely low radiation intensities, very sensitive detectors are used. Therefore, to avoid measurement inaccuracies, it is necessary to ensure that only radiation generated by the inspection device strikes the detector. In addition, care must be taken to ensure that only radiation diffracted at a single point is detected, since localization within the object to be inspected is otherwise impossible. Thus, spatial filtering is necessary, which is accomplished by a so- collimator. Since it is technically very complicated to generate monochromatic X-rays, the sharply defined X-ray beam used for inspection, which is known as a pencil beam, has an energy spectrum that is known from measurements, for example. The result of the Bragg equation is that the incident radiation is diffracted at every point through an angle that depends on the energy of the radiation. Thus, radiation with an energy spectrum is diffracted over an angular range; the diffraction here is rotationally symmetric about the incident pencil beam. In an X-ray inspection, it is desirable to detect only radiation diffracted through a specific angle. This, too, is achieved through the use of a collimator. The transmission range of the collimator corresponds essentially to the surface of a cone whose tip coincides with the point whose diffraction characteristics are to be examined. To examine a region within an object, a large number of points must be focused. For this purpose, it is known to use a collimator that has multiple parallel apertures with the same aperture angle, and with which it is thus possible to simultaneously focus multiple points on the axis of rotation. However, the use of a non-segmented detector that does not resolve position, and thus provides a common output signal for all focused points, has the disadvantage that the analysis and unambiguous association of the detected radiation to a point of diffraction are difficult. While this disadvantage does not arise when using a segmented detector, which is divided into circular rings that can be analyzed separately, for example, such a detector is complicated and expensive. Known from German patent application 103 30 521.1, which is incorporated herein by reference, is a method for examining an object space in which the arrangement includes a detector and collimator can be made to travel in the direction of the incident X-ray beam. However, the entire apparatus must have an overall height of more than twice the height of the object to be examined. It is therefore an object of the present invention to provide a collimator such that shorter travel paths and thus reduced overall height of the X-ray inspection device result. Basically, a collimator according to the invention has an outer part that can simultaneously assume the function of a housing and has a conical inner surface, and an inner part that has a conical outer surface. These two parts are rigidly connected to one another at a fixed distance, so that a gap is formed between them. Located in this gap is at least one movably arranged hollow cone, which is also called a cone sliding part. The focal length of the collimator can be varied by sliding the movable cone or cones. As already described above, ideally only radiation diffracted at one angle from one point reaches the X-ray detector in X-ray inspection systems. Thus, spatial filtering is necessary. In this regard, the optimal spatial filter characteristic is one that results in a transmission range having the shape of the surface of a cone. This is achieved in the inventive collimator by the means that all conical surfaces are arranged concentrically about a common axis of rotation, wherein the axis of rotation corresponds to the direction of incidence of the pencil beam. To identify a substance in an object to be inspected, the diffraction spectrum detected at a specific angle is compared to the spectrum of the pencil beam. It follows from the Bragg equation that a diffraction spectrum recorded at a different angle is displaced relative to the first. Consequently, identification is simplified if every measurement is performed using the same aperture angle. A constant detection angle of the collimator is achieved by the means that all conical surfaces have the same aperture angle. Different detection angles as a function of the focal length that is set can be achieved through different aperture angles of the conical surfaces. It is advantageous in this regard for every pair of adjacent conical surfaces to have the same aperture angle. As a result of this paired matching, large areas of the conical surfaces rest against one another, resulting in high radiation absorption by the collimator. The focal length is set by the means that the at least one cone sliding part can be made to travel along the axis of rotation. In this way, the focus of the collimator can be adjusted by a simple translational motion of the cone sliding part in one direction. Hence, the adjustment of the focal length of the collimator, and thus of the focused point in the object to be inspected, is accomplished by the means that the at least one cone sliding part is moved along the axis of rotation until the desired focal length is achieved, wherein, when multiple sliding cones are used, they can be moved independently of one another. In order to achieve an optimal spatial filtering effect, the cone sliding part or parts should always be positioned such that the collimator has only one aperture gap. When all conical surfaces are arranged concentrically about a common axis of rotation, and adjacent surfaces each have the same aperture angle, the surfaces fit closely against one another over their entire height. Except in the region of the selected gap, the entire collimator thus appears as a solid unit, permitting maximum shielding of the unwanted X-rays. As a result of the fact that the individual cone sliding parts can be moved independently of one another, it is thus possible to create a single gap at various positions. This permits an equal number of possible focal lengths. For a number n of cone sliding parts, the result is n+1 possible gaps. A number of advantageous possible applications exist for a collimator with adjustable focal length according to the present invention. In a first case, the collimator can be held at a fixed position and multiple points in an object can be focused by moving the cone sliding part or parts. Alternatively, it is possible to move the collimator linearly, thus performing a continuous measurement of the object to be inspected. In this case, the travel path can be reduced by the means that the focal length is switched after the collimator has traveled a certain path, and a different examined region results when the collimator is moved along the same path anew. In the ideal case, the maximum required travel path of the inventive collimator is reduced as compared to a nonadjustable collimator by a factor corresponding to the number of focal lengths that can be set, or in other words by half in the case of a collimator with two focal lengths. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In all the figures, the inventive collimator has an outer part 1 and an inner part 2; these parts are arranged concentrically about an axis of rotation 4. In FIGS. 1a and 1b the collimator has one cone sliding part, while it has two cone sliding parts in FIG. 2. Such collimators find particular application in X-ray inspection systems, especially in higher stages of multi-stage inspection systems. In FIG. 1a, the cone sliding part 3 is located in an end position in which it rests against the inner part 2. Consequently, a transmission gap for the radiation results between the cone sliding part 3 and outer part 1. In this case, the collimator filters out all radiation that is not diffracted through an angle α from a point at a distance d1 from the collimator. In FIG. 1b, the cone sliding part 3 is resting against the outer part 1. Consequently, a transmission gap results between the cone sliding part 3 and inner part 2. The aperture angle α of the collimator remains unchanged, but in this position a point at a distance d2 from the collimator is focused. It is immediately evident that switching the position of the cone sliding part 3 varies the region focused during travel of the collimator. This means that the travel path of the collimator is reduced for a specific region to be inspected. In the extreme case, this savings amounts to half the extent of the region to be inspected. In FIG. 2, the collimator again has an outer part 1 and an inner part 2, but has two cone sliding parts 5 and 6 that are movable independently of one another. In the position shown, the cone sliding part 5 rests against the outer part 1 and the cone sliding part 6 rests against the inner part 2. The result is a focusing on a point at a distance d3, again at the aperture angle α. In case that the cone sliding parts 5 and 6 rest against one another, the result is the focal lengths d1 and d2 already shown in FIGS. 1a and 1b. The focal length of the inventive collimator is adjusted by the means that the at least one cone sliding part 3 is moved along the axis of rotation 4 until the desired focal length is achieved, wherein, when multiple sliding cones 5, 6 are used, they can be moved independently of one another. In one preferred application, the inventive collimator with adjustable focal length is part of an X-ray inspection system that also has an X-ray source, an X-ray detector and an analysis device for analyzing the detected radiation. The two aforementioned example embodiments are purely exemplary in nature and are thus not limiting. In particular, the number and size of the cone sliding parts can vary without departing from the concept of the invention. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
055552790	claims	1. A computer-based power oscillation monitoring system for detection and indication of thermal-hydraulic stability margin in a nuclear reactor having a core including a plurality of fuel assemblies, said system comprising: a) a plurality of neutron flux detectors in the nuclear reactor core contiguous to the fuel assemblies, said plurality of flux detectors being distributed throughout the reactor core, said plurality of flux detectors providing a like plurality of output signals, each output signal being indicative of the neutron flux of the portion of the core adjacent the corresponding flux detector; b) a computer-based detector processing system utilizing: c) a corrective signal means for improving reactor stability margin when said simulated decay ratio signal reaches a predetermined level. a) a plurality of neutron flux detectors in the nuclear reactor core contiguous to the fuel assemblies, said plurality of flux detectors being distributed throughout the reactor core, said plurality of flux detectors providing a like plurality of output signals, each output signal being indicative of the neutron flux of the portion of the core adjacent the corresponding flux detector, said plurality of output signals being organized into a plurality of flux detector output signal groups; b) a frequency filter for removing select frequency components of said flux detector output signals that are of a frequency in excess of a characteristic frequency range of a thermal-hydraulic instability; c) a computer-based detector processing system utilizing: d) a corrective signal means for improving reactor stability margin when said simulated decay ratio signal reaches a predetermined level. a) a plurality of neutron flux detectors in the nuclear reactor core contiguous to the fuel assemblies, said flux detectors being approximately equally distributed throughout the reactor core, said plurality of flux detectors providing a like plurality of output signals, each output signal being indicative of the power density of the portion of the core adjacent the corresponding flux detector, said plurality of output signals organized into one or more flux detector output signal groups; b) a computer-based detector processing system utilizing: c) a corrective signal means for improving reactor stability margin when said simulated decay ratio signal reaches a predetermined level. a) a plurality of neutron flux detectors in the nuclear reactor core contiguous to the fuel assemblies, said flux detectors being distributed throughout the reactor core, said plurality of flux detectors providing a like plurality of output signals, each said output signal being indicative of the neutron flux of the portion of the core adjacent the corresponding flux detector, said plurality of output signals being organized into one or more flux detector output signal groups; b) a frequency filter for removing select frequency components of said flux detector output signals that are of a frequency in excess 0.7 Hz; c) a computer-based detector processing system utilizing: d) a suppression signal means for issuing an oscillation suppression signal when said simulated decay ratio signal in any group reaches a predetermined level. a) providing a plurality of neutron flux detectors in the nuclear reactor core contiguous to the fuel assemblies, said plurality of flux detectors being distributed throughout the reactor core, said plurality of flux detectors providing a like plurality of output signals, each output signal being indicative of the power density of the portion of the core adjacent the corresponding flux detector; b) processing said output signal of each flux detector utilizing a computer-based detector processing system by the steps of: c) providing a corrective signal means for improving reactor stability margin when said simulated decay ratio signal reaches a predetermined level. a) providing a plurality of neutron flux detectors in the nuclear reactor core contiguous to the fuel assemblies, said plurality of flux detectors being distributed throughout the reactor core, said plurality of flux detectors providing a like plurality of output signals, each output signal being indicative of the neutron flux of the portion of the core adjacent the corresponding flux detector; b) providing a frequency filter for removing select frequency components of said flux detector output signals that are of a frequency in excess of a characteristic frequency range of a thermal-hydraulic instability; c) processing said output signal of each flux detector utilizing a computer-based detector processing system by the steps of: d) providing a corrective signal means for improving reactor stability margin when said simulated decay ratio signal reaches a predetermined level. a) providing a plurality of neutron flux detectors in the nuclear reactor core contiguous to the fuel assemblies, said flux detectors being distributed throughout the reactor core, said plurality of flux detectors providing a like plurality of output signals, each output signal being indicative of the power density of the portion of the core adjacent the corresponding flux detector, said plurality of output signals being organized into a one or more flux detector output signal groups; b) processing said output signal of each flux detector utilizing a computer-based detector signal processing system by the steps of: c) providing a corrective signal means for improving reactor stability margin when said simulated decay ratio signal reaches a predetermined level. a) providing a plurality of neutron flux detectors in the nuclear reactor core contiguous to the fuel assemblies, said flux detectors being distributed throughout the reactor core, said plurality of flux detectors providing a like plurality of output signals, each output signal being indicative of the power density of the portion of the core adjacent the corresponding flux detector, said plurality of output signals being organized into one or more of flux detector output signal groups; b) filtering for removal of select frequency components of said flux detector output signals that are of a frequency in excess 0.7 Hz; c) processing said output signal of each flux detector utilizing a computer-based detector signal processing system by the steps of: d) a suppression signal means for issuing an oscillation suppression signal when said simulated decay ratio signal in any group reaches a predetermined level. 2. The computer-based oscillation detection system of claim 1, wherein said system includes a frequency filter for removing select frequency components of said flux detector output signals that are of a frequency in excess of a characteristic frequency range of a thermal-hydraulic instability. 3. The filter of claim 2, wherein the filter provides for removal of select components of said flux detector output signal that are of a frequency greater than approximately 0.7 Hz. 4. The computer-based oscillation detection system of claim 1, wherein the neutron flux detectors are local power range monitors. 5. The computer-based oscillation detection system of claim 1, wherein the simulated decay ratio algorithm divides the plurality of flux detector output signals into a plurality of groups, each group corresponding to a plurality of flux detectors spread throughout the core, and each group being processed individually and simultaneously to yield the simulated decay ratio signal. 6. The computer-based oscillation detection system of claim 1, wherein the simulated decay ratio algorithm includes a spike rejection means to minimize the effect of unexpected, single, large deviations in the periodicity signals of the flux detectors. 7. The computer-based oscillation detection system of claim 1, wherein the simulated decay ratio algorithm includes a smoothing function means. 8. A computer-based power oscillation monitoring system for detection and indication of thermal-hydraulic stability margin in a nuclear reactor having a core including a plurality of fuel assemblies, said system comprising: 9. A computer-based power oscillation monitoring system for detection and indication of thermal-hydraulic stability margin in a nuclear reactor having a core including a plurality of fuel assemblies, said system comprising: 10. The computer-based oscillation detection system of claim 9, wherein said system includes a frequency filter for removing frequency components of said flux detector output signals that are of a frequency in excess of a characteristic frequency range of a thermal-hydraulic instability. 11. The filter of claim 10, wherein the filter provides for removal of select components of said flux detector output signal that are of a frequency greater than approximately 0.7 Hz. 12. The computer-based oscillation detection system of claim 9, wherein the neutron flux detectors are local power range monitors. 13. The computer-based oscillation detection system of claim 9, wherein said time block is in the range of approximately 1 to 60 seconds. 14. The computer-based oscillation detection system of claim 9, wherein said time block is dynamically established. 15. The computer-based oscillation detection system of claim 9, wherein the simulated decay ratio algorithm includes a spike rejection means to generate an effective successive confirmation count signal based on the block successive confirmation count signal to minimize the effect of unexpected, single, large deviations in the block successive confirmation count signal. 16. The computer-based oscillation detection system of claim 9, wherein the simulated decay ratio algorithm includes a smoothing function means to process the effective confirmation count signal to generate a nominal successive confirmation count signal that minimizes changes in the block successive confirmation count resulting from statistical variations from one time block to another. 17. The computer-based oscillation detection system of claim 9, wherein the simulated decay ratio algorithm includes a spike rejection means to generate an effective successive confirmation count signal based on the block successive confirmation count signal to minimize the effect of unexpected, single, large deviations in the block successive confirmation count signal, and a smoothing function means to process the effective successive confirmation count signal to generate a nominal successive confirmation count signal that minimizes changes in the block successive confirmation count resulting from statistical variations from one time block to another. 18. A computer-based power oscillation monitoring system for detection and indication of thermal-hydraulic instabilities in a nuclear reactor having a core including a plurality of fuel assemblies, said system comprising: 19. A computer-based method for detecting, monitoring and indicating thermal-hydraulic stability margin in a nuclear reactor having a core including a plurality of fuel assemblies, said system comprising: 20. The computer-based method of claim 19, wherein said method includes providing a frequency filter for removing frequency components of said flux detector output signals that are of a frequency in excess of a characteristic frequency range of a thermal-hydraulic instability. 21. The computer-based method of claim 20, wherein the step of providing the filter provides for removal of select components of said flux detector output signal that are of a frequency greater than approximately 0.7 Hz. 22. The computer-based method of claim 19, wherein the step of providing the neutron flux detectors includes providing local power range monitors spatially distributed throughout the core. 23. The computer-based method of claim 19, wherein the step of processing the output signal employing the simulated decay ratio algorithm includes dividing the plurality of flux detector output signals into one or more groups, each group corresponding to a plurality of flux detectors spread throughout the core, and each group being processed individually and simultaneously to yield the simulated decay ratio signal. 24. The computer-based method of claim 19, wherein the step of processing the output signal employing the simulated decay ratio algorithm includes employing a spike rejection means to minimize the effect of unexpected, single, large deviations in the periodicity signals of the flux detectors. 25. The computer-based method of claim 19, wherein the step of processing the output signal employing the simulated decay ratio algorithm includes employing a smoothing function means. 26. A computer-based method for detecting, monitoring and indicating thermal-hydraulic stability margin in a nuclear reactor having a core including a plurality of fuel assemblies, said system comprising: 27. A computer-based method for detecting, monitoring, and indicating thermal-hydraulic stability margin in a nuclear reactor having a core including a plurality of fuel assemblies, said system comprising: 28. The computer-based method of claim 27, including frequency filtering for removal of select frequency components of said flux detector output signals that are of a frequency in excess of a characteristic frequency range of a thermal-hydraulic instability. 29. The filter of claim 28, wherein the step of filtering includes removing select components of said flux detector output signal that are of a frequency greater than approximately 0.7 Hz. 30. The computer-based method of claim 27, wherein the neutron flux detectors are local power range monitors. 31. The computer-based method of claim 27, wherein each said time block is in the range of approximately 1 to 60 seconds. 32. The computer-based method of claim 11, wherein said time block is dynamically established. 33. The computer-based method of claim 27, including providing a spike rejection means to generate an effective successive confirmation count signal based on the block successive confirmation count signal to minimize the effect of unexpected, single, large deviations in the block successive confirmation count signal. 34. The computer-based method of claim 27, including providing a smoothing function means to process the effective confirmation count signal to generate a nominal successive confirmation count signal that minimizes changes in the block successive confirmation count resulting from statistical variations from one time block to another. 35. The computer-based method of claim 27, including providing a spike rejection means to generate an effective successive confirmation count signal based on the block successive confirmation count signal to minimize the effect of unexpected, single, large deviations in the block successive confirmation count signal, and a smoothing function means to process the effective successive confirmation count signal to generate a nominal successive confirmation count signal that minimizes changes in the block successive confirmation count resulting from statistical variations from one time block to another. 36. A computer-based method for detecting, monitoring and indicating thermal-hydraulic stability margin in a nuclear reactor having a core including a plurality of fuel assemblies, said system comprising:
	description	This patent application claims the benefit of priority under 35 U.S.C. § 119(b) from Korean Patent Application No. 10-2013-0135327 filed Nov. 8, 2013, the contents of which are incorporated herein by reference. 1. Field of the Invention The present disclosure relates to an emergency core cooling system and an emergency core cooling method for a water-cooled reactor system, and more particularly, to an emergency core cooling system and an emergency core cooling method for a fail-safe water-cooled reactor, which completely removes decay heat generated from a core in safety while an active component such as a pump is not used. 2. Description of the Related Art Doubts of the general public about safety of a nuclear power plant have been significantly increased due to the nuclear accident occurring in Fukushima, Japan, on Mar. 11, 2011, and thus various countermeasures improving safety of an existing nuclear power plant have been provided. Meanwhile, most nuclear reactors of nuclear power plants throughout the world as well as the nuclear reactor of the nuclear accident occurring in Japan are water-cooled reactors. In the water-cooled reactor, water is used as a coolant of a core, and examples thereof include a pressurized water reactor, a pressurized heavy water reactor, and a boiling water reactor. The most important object to be solved in order to increase safety of the water-cooled reactor is to effectively remove decay heat continuously generated even after the nuclear reactor is shut down due to radioactive decay of nuclear fission products when the nuclear reactor is shut down. To this end, in the water-cooled reactor, an emergency core cooling system (ECCS) for removing decay heat after the nuclear reactor is shut down is provided to cope with the case where a loss of coolant accident (LOCA) occurs or water is not supplied through a main feedwater system or an auxiliary feedwater system due to an accident. An emergency core cooling system of a commercial nuclear power plant is generally constituted by a safety injection tank, a safety injection system, and a recirculation system. The safety injection tank passively supplies water stored in a compression tank into a reactor vessel by using a pressure difference when the loss of coolant accident occurs. In addition, the safety injection system actively supplies cooling water from an in-containment refueling water storage tank into the reactor vessel by using an active component such as a pump. In addition, when water of the in-containment refueling water storage tank is used up, the recirculation system supplies back cooling water collected in a recirculation sump provided on the bottom of a containment into the reactor vessel by using the pump. As described above, since the emergency core cooling system of the commercial nuclear power plant has a limited cooling water volume of the safety injection tank, an active system using the pump as well as a passive system is necessarily required to cool a core over a long period of time. However, when a nuclear accident accompanied by a station blackout (SBO) where electric power supply is cut off over a long period of time occurs, the active system of the emergency core cooling system cannot be used, accordingly, the core cannot be cooled over a long period of time. Therefore, in the case where emergency core cooling is required, a passive emergency core cooling system needs to be developed, which can completely remove decay heat generated from the core in safety while the active component such as the pump is not used and the core is not exposed. See Korean Patent No. 813,939 and Korean Patent No. 1,242,746 for related art documents. Embodiments of the present invention are directed to provide an emergency core cooling system and an emergency core cooling method for a fail-safe water-cooled reactor system, which completely remove decay heat generated from a core in safety only by a passive method not using an active component. According to an aspect of the present invention, there is provided an emergency core cooling system for a fail-safe water-cooled reactor system, including a reactor vessel using water as a coolant and a moderator, and receiving therein a reactor core on which nuclear fission occurs; a containment surrounding the entire reactor system including the reactor vessel and condensing a vapor discharged from the reactor vessel when emergency core cooling is performed; a reactor cavity which surrounds the reactor vessel and in which water condensed in the containment is collected due to gravity; a first cavity pipe provided to pass through the reactor vessel; and a cavity valve provided on the cavity pipe to open the first cavity pipe when emergency core cooling is performed and thus discharge the vapor generated from the reactor vessel to an outside. In the emergency core cooling system according to the present invention, it is preferable that the containment be formed of steel to condense the vapor discharged from the reactor vessel on a surface of an inner wall. Also, a heat exchanger may be provided in the containment to condense the vapor discharged from the reactor vessel on the heat exchanger. Also, it is preferable that the cavity valve is operated by an alternating current (AC) power supply, or is operated by a direct current (DC) power supply such as a battery when the AC power supply is unable to be used. Also, it is preferable that the first cavity pipe be disposed in an upper portion of the reactor vessel. In this case, the first cavity pipe may be provided in plurality and the plurality of first cavity pipes may be placed at the same height. Also, the emergency core cooling system according to the present invention may further include a second cavity pipe provided to pass through the reactor vessel to be placed at the same height as the first cavity pipe; and a rupture disk provided in the second cavity pipe and ruptured due to an increase in internal pressure of the reactor vessel when the cavity valve is not operated during emergency core cooling to thereby open the second cavity pipe. According to another aspect of the present invention, there is provided an emergency core cooling method for a fail-safe water-cooled reactor system, including opening a cavity valve of a first cavity pipe provided to pass through a reactor vessel, by operating an emergency core cooling system when an accident requiring emergency core cooling occurs in the water-cooled reactor system (S100); discharging a vapor generated from a core due to decay heat through the opened first cavity pipe to an outside of the reactor vessel (S200); condensing the discharged vapor in a containment (S300); allowing water condensed in the containment to flow down due to gravity and thus to be collected in a reactor cavity surrounding the reactor vessel (S400); allowing cooling water collected in the reactor cavity to flow into the reactor vessel through the first cavity pipe due to gravity (S500); and removing decay heat by cooling water flowing into the reactor vessel (S600). In the emergency core cooling method according to the present invention, it is preferable that the cavity valve be operated by an alternating current (AC) power supply or operated by a direct current (DC) power supply such as a battery when a station blackout occurs. Also, the opening of the cavity valve of the first cavity pipe (S100) further includes opening the second cavity pipe provided through the reactor vessel when the cavity valve is not opened (S150). Also, the removing of decay heat in the reactor vessel (S600) is performed by allowing the vapor generated due to decay heat and cooling water of the reactor cavity to flow in opposite directions through the opened first cavity pipe or an opened second cavity pipe, respectively and thus perform recirculation of cooling water. As described above, an emergency core cooling system and an emergency core cooling method for a fail-safe water-cooled reactor system according to preferred embodiments of the present invention have an effect of removing decay heat generated from a core while an active component such as a pump is not used, that is, only by a passive method, unlike an existing emergency core cooling system. Therefore, even though an accident accompanied by a station blackout occurs to require emergency core cooling, it is possible to completely remove decay heat in safety while the core is not exposed. Other objects, specific advantages, and novel features of the present invention will be more clearly understood by the accompanying drawings, the following detailed description, and preferred embodiments. The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which the most preferred embodiment of the present invention is shown so as to be easily understood by the person with ordinary skill in the art to which the present invention belongs. Also, it should be understood that detailed descriptions of well-known functions and structures related to the present invention will be omitted so as not to unnecessarily obscure the important point of the present invention. In addition, for addition of reference numerals, the same elements will be designated by the same reference numerals even though the reference numerals are shown in different drawings. Emergency Core Cooling System for Fail-Safe Water-Cooled Reactor System FIG. 1 is a schematic diagram illustrating an emergency core cooling system for a fail-safe water-cooled reactor system according to an embodiment of the present invention. The emergency core cooling system according to the present invention can be applied to all water-cooled reactor systems such as a boiling water reactor and a pressurized water reactor, in which water is used as a coolant and a moderator and nuclear fission occurs. The emergency core cooling system according to the embodiment of the present invention includes, as illustrated in FIG. 1, a reactor vessel 10, a containment 20, a reactor cavity 30, a first cavity pipe 42, and a cavity valve 50. The reactor vessel 10 receives a reactor core (not illustrated) therein. As illustrated in FIG. 1, the containment 20 is a spherical or bell-shaped structure surrounding the entire reactor system including the reactor vessel 10 and the reactor cavity 30. The containment is sealed and pressure-resistant to prevent radioactive materials from being discharged to the outside when an accident such as breakage of the reactor vessel 10 occurs. Further, when an accident requiring emergency core cooling occurs in the emergency core cooling system according to the present invention, the containment 20 functions to condense a vapor discharged from the reactor vessel 10. To this end, according to the present embodiment, the containment 20 made of steel having high thermal conductivity is used instead of the containment made of concrete having low thermal conductivity unlike an existing nuclear power plant. Accordingly, decay heat generated from the core may be effectively discharged to the outside of the power plant by condensing the vapor discharged from the reactor vessel 10 during emergency core cooling on a surface of an inner wall of the steel containment 20. Meanwhile, according to another embodiment of the present invention, when the existing containment made of concrete is used, a separate heat exchanger 70 can be provided in the containment 20 to condense the vapor discharged from the reactor vessel 10 on the heat exchanger. As illustrated in FIG. 1, the reactor cavity 30 is formed to be spaced a predetermined distance apart from an outer circumference of the reactor vessel 10 and surround the reactor vessel, and water condensed on the containment 20 is collected therein. That is, water condensed on the containment 20 positioned over the reactor cavity 30 is passively collected in the reactor cavity 30 due to gravity, and thus a level of cooling water collected in the reactor cavity 30 ascends. The first cavity pipe 42 is a pipe providing a path connecting the inside and the outside of the reactor vessel 10. According to the present embodiment, as illustrated in FIG. 1, the first cavity pipe 42 is provided to pass through an upper portion of the reactor vessel 10. In this case, the first cavity pipe 42 is provided at a position that is lower than an upper end of the reactor cavity 30. Through the first cavity pipe 42, the vapor generated in the reactor vessel 10 may be discharged to the outside of the reactor vessel 10 during emergency core cooling. Furthermore, as described above, when a level of cooling water collected in the reactor cavity 30 is positioned to be higher than the first cavity pipe 42, cooling water may flow into the reactor vessel 10 due to gravity. In this case, in the first cavity pipe 42, the vapor generated in the reactor vessel 10 and cooling water collected in the reactor cavity 30 flow in opposite directions, respectively. Accordingly, a recirculation loop of cooling water of the emergency core cooling system according to the present invention is formed. As illustrated in FIG. 1, the cavity valve 50 is provided in the first cavity pipe 42 to open and close the first cavity pipe 42. The cavity valve 50 is closed during a normal operation to close the first cavity pipe 42, and receives an opening control signal from a control system (not illustrated) to open the first cavity pipe 42 when the emergency core cooling system of the present invention is operated. In addition, it is preferable that the cavity valve 50 be operated by an alternating current (AC) power supply when a normal operation is performed or an accident other than a station blackout (SBO) occurs and by a direct current (DC) power supply such as a battery in case of emergency such as the station blackout, in which the alternating current power supply cannot be used. Accordingly, it is possible to solve a problem in that emergency core cooling is not performed because of the cavity valve 50 being not operated when the station blackout accident occurs. Meanwhile, FIG. 1 illustrates only one first cavity pipe 42 having the cavity valve 50, but according to the present embodiment, the two or more first cavity pipes 42 may be provided to be placed at the same height along a circumference of reactor vessel 10. According to this, the vapor and cooling water may be flow through a plurality of first cavity pipes 42 (see FIG. 4) to further improve efficiency of emergency core cooling. Further, even though one first cavity pipe 42 is not opened due to the reason such as failure in cavity valve 50, emergency core cooling may be performed through another first cavity pipe 42, and thus safety of the emergency core cooling system may be further secured. FIG. 2 is a schematic diagram illustrating an emergency core cooling system for a fail-safe water-cooled reactor system according to another embodiment of the present invention. As illustrated in FIG. 2, the emergency core cooling system according to another embodiment of the present invention further includes a second cavity pipe 44 and a rupture disk 60. Since other elements are the same as the aforementioned descriptions, repeated description will be omitted herein. As illustrated in FIG. 2, the second cavity pipe 44 is provided to pass through the upper portion of the reactor vessel 10 to be placed at the same height as the first cavity pipe 42. The rupture disk 60 acts as an emergency valve to cope with the case of occurrence of an accident that the aforementioned cavity valve 50 of the first cavity pipe 42 is not opened due to failure. The rupture disk 60 is provided in the second cavity pipe 44 to be ruptured when a predetermined pressure or more is applied. The rupture disk 60 closes the second cavity pipe 44 during the normal operation or when the cavity valve 50 is opened during emergency core cooling. In addition, in the case where the cavity valve 50 is not opened when an accident requiring emergency core cooling occurs, if an internal pressure of the reactor vessel 10 is increased to reach a predetermined value or more, the rupture disk 60 is ruptured to open the second cavity pipe 44 and thus perform emergency core cooling. As described above, the emergency core cooling system according to the present invention may further include the second cavity pipe 44 and the rupture disk 60 to prevent in advance an accident that emergency core cooling is not performed due to failure in cavity valve 50 or parts driving the cavity valve 50 when the accident requiring emergency core cooling occurs. Emergency Core Cooling Method for Fail-safe Water-cooled Reactor System Hereinafter, an emergency core cooling method for a fail-safe water-cooled reactor system will be described with reference to FIGS. 1 to 3. FIG. 3 is a flow chart showing an emergency core cooling method for a fail-safe water-cooled reactor system according to a preferred embodiment of the present invention. In the emergency core cooling method according to the present invention, first, when an accident requiring emergency core cooling, such as a loss of coolant accident (LOCA) or an accident that water is not supplied through a main feedwater system or an auxiliary feedwater system, occurs, an emergency core cooling system is operated, and thus a control system (not illustrated) transmits a signal for opening the cavity valve 50 to open the cavity valve 50 of the first cavity pipe 42 provided to pass through the reactor vessel 10 (S100). In this case, when a plurality of first cavity pipes 42 and cavity valves 50 are provided in the reactor vessel 10, depending on conditions all of the cavity valves 50 are opened or a part of the cavity valves 50 is selectively opened. In addition, the control system (not illustrated) may sense the accident requiring emergency core cooling by using a sensor to automatically transmit a control signal for opening the cavity valve 50. Further, a manager can directly operate generation of the control signal. In addition, the cavity valve 50 may be operated by an alternating current (AC) power supply when an accident other than a station blackout (SBO) occurs or operated by a direct current (DC) power supply such as a battery in the case of occurrence of the station blackout accident that the alternating current power supply cannot be used. Meanwhile, in the aforementioned step (S100), when an accident that the cavity valve 50 is not opened occurs, the rupture disk 60 of the second cavity pipe 44 provided to pass through the reactor vessel 10 is ruptured due to an increase in an internal pressure of the reactor vessel 10 to open the second cavity pipe 44 (S150). That is, the present invention may prevent in advance an accident that emergency core cooling is not performed due to failure in cavity valve 50 or parts driving the cavity valve 50 by using the second cavity pipe 44 and the rupture disk 60. That is, the second cavity pipe 44 may act as a substitute for the role of the first cavity pipe. Next, when the cavity valve 50 is opened, the vapor generated due to decay heat in the reactor vessel 10 is discharged through the first cavity pipe 42 to the outside (S200). In this case, when an accident that the cavity valve 50 is not opened occurs, as described above, the vapor is discharged through the second cavity pipe 44 to the outside. Next, the vapor discharged through the first cavity pipe 42 or the second cavity pipe 44 moves through the reactor cavity 30 to the containment 20 to be heat-exchanged while being condensed (S300). At this time, when the containment is made of steel, the vapor is condensed on a surface of an inner wall of the containment 20; and when the containment is made of concrete, the vapor is condensed on a heat exchanger (not illustrated) provided in the containment. Accordingly, in the case of the containment made of steel, decay heat generated from the core is transferred to the containment 20 during condensing of the vapor on the inner wall of the containment 20, and finally, decay heat is removed by heat-exchanging with an external environment due to radiation and convection of air. In the case of the containment made of concrete, decay heat is discharged to the outside of the containment while the vapor is condensed on the heat exchanger, and finally, decay heat is removed due to convection of water or air in a tank provided on an external wall of the containment. Next, water condensed in the containment 20 flows down due to gravity to be collected in the reactor cavity 30 surrounding the reactor vessel 10 (S400). In this case, the vapor is continuously condensed while decay heat is removed, and condensed water is passively collected in the reactor cavity 30 to allow a water level of the reactor cavity 30 to ascend. Next, cooling water collected in the reactor cavity 30 passively moves into the reactor vessel 10 through the first cavity pipe 42 due to gravity (S500). In this case, when the accident that the cavity valve 50 is not opened occurs, cooling water flows into the reactor vessel 10 through the second cavity pipe 44 in which the rupture disk 60 is ruptured. Finally, cooling water of the emergency core cooling system is recirculated until decay heat generated from the core is completely removed (S600). Here, In the first cavity pipe 42 or the second cavity pipe 44, the vapor generated in the reactor vessel 10 and cooling water collected in the reactor cavity 30 flow in opposite directions, respectively. That is, a recirculation loop of cooling water of the emergency core cooling system is formed. In addition, when decay heat is completely removed, the accident is finally finished. Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
	summary
044477295	claims	1. A cylindrical container for the transportation of radioactive reactor elements, said container including a top end, a bottom end and a pair of removable outwardly curved shock absorbers each including a double-shelled construction having an internal shell and an external shell with a convex extrados configuration, said shock absorbers being filled with low density energy-absorbing material and mounted at said top end and said bottom end of the container, respectively, and each of said shock absorbers having a toroidal configuration, and deformable tubes disposed therein and extending in the axial direction of said container. 2. A container as claimed in claim 1, wherein said external shell is thicker than said internal shell. 3. A container as claimed in claim 2, wherein the container has a body, the internal and external shells are made from rustproof steel, said shells having rims which are welded to an annular flange which is secured to the container body. 4. A container as claimed in claim 3, wherein said deformable tubes have a thick-wall configuration and are welded to the external shell and to the annular flange. 5. A container as claimed in claim 1, wherein said container includes an outer casing which encloses a cylinderical annular chamber, said annular chamber including a water-filled chamber and a gas-filled expansion chamber positioned in spaced relation thereto, said gas-filled expansion chamber having a concentrically disposed metal bellows positioned therein. 6. A container as claimed in claim 5, wherein the ends of the annular chamber are closed by side ribs, said side ribs being deformable for absorbing kinetic energy. 7. A container as claimed in claim 1, wherein said container includes partially deformable lifting lugs which are disposed at said bottom and said top ends of the container for absorbing energy. 8. A container as claimed in claim 1, wherein said toroidal configuration has an axis, and said deformable tubes are arranged in a circle in said container about an axis concentric with the axis of said toroidal configuration. 9. A container as claimed in claim 1 wherein said internal shell has a convex intrados configuration.
048797359	description	DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a perspective view of an improved baggage inspection device of the present invention. An X-ray baggage inspection device 11 consists of a housing 13 having an input port 15 (FIG. 2) and an output port 17 (FIG. 2), disposed above a Conveyor 19, having a first location 21 and a second location 23 for transporting baggage between the first location 21 and the second location 23. In one preferred embodiment, the input port 15 has an upper boundary 25 defined by housing 13, and a lower boundary 27 defined by conveyor 19. A substantially rigid baffle 29, having an upper edge 31 and a lower edge 33, is pivotally suspended from upper boundary 25 of housing 13 at upper edge 31. Baffle 29 comprises a substantially flat monolithic rectangular plate that is pivotally suspended from upper boundary 25 by a hinge 35. Baffle 29 substantially occludes an upper selected region 37 of input port 15. Lower edge 33 of baffle 29 is spaced a preselected distance above conveyor 19, leaving an open space adjacent to conveyor 19 that is identified in FIG. 2 as lower selected region 39. Lower selected region 39 has a configuration suited for the passage of briefcase type baggage horizontally disposed upon said conveyor 19 beneath lower edge 33 of baffle 29. Briefcase type baggage is baggage of the type having a vertical height that is much greater than its width, often used for the transportation of papers, clothing, books, and personal effects. The definition of briefcase type baggage is broad enough to include briefcases, purses, clutches, and other small pieces of luggage referred to in the industry as "carry-on luggage". The width of baggage horizontally disposed upon Conveyor 19 is referred to hereinafter as the "horizontal height" of the baggage. Since baffle 19 is pivotally suspended from upper boundary 25, it will pivot inward in response to the passage of baggage having a horizontal height exceeding the preselected distance between lower boundary 27 and lower edge 33 of baffle 29. During normal operation, baffle 19 is pivotally suspended from upper boundary 25 in a position substantially normal relative to conveyor 19; as oversize horizontally disposed baggage or vertically disposed baggage is advanced along conveyor 19, baffle 29 will be urged into an angular position relative to conveyor 19. FIG. 2 is a longitudinal section of the improved X-ray baggage inspection device of FIG. 1. Briefcase type baggage 41 is horizontally disposed upon conveyor 19 at first location 21 for transportation through housing 13 to output port 17, wherein X-ray baggage inspection device 11 serves to non-intrusively inspect the content of briefcase type baggage 41. Specifically, X-ray baggage inspection device 11 is utilized to inspect for firearms or explosives. Baffle 29 is shown suspended from upper boundary 25 in a position substantially normal relative to conveyor 19, but is depicted in phantom at an angular position relative to conveyor 19. Baffle 29 serves to encourage the horizontal placement of baggage on conveyor 19. A traveler approaching the X-ray baggage inspection device 11 will assume that baffle 29 is rigidly mounted in selected upper region 37 of input port 15, preventing the vertical placement of baggage. In addition, the traveler will recognize that selected lower region 34 has a configuration suited for the passage of briefcase type baggage horizontally disposed upon conveyor 19. Since baffle 29 is pivotally suspended from upper boundary 25, it will pivot inward in response to briefcase type baggage 41 having a horizontal height exceeding the preselected distance between conveyor 19 and lower edge 33 of baffle 29. In addition, baffle 29 will pivot inward in response to briefcase type baggage 41 vertically disposed upon conveyor 19. Baffle 29 will pivot inward to oversize baggage horizontally disposed on conveyor 19. "Oversize" baggage is considered herein to refer to baggage that will fit through input port 15, but which when horizontally disposed on conveyor 19, has a height greater than the lower region 39. In one preferred embodiment, the preselected distance between conveyor 19 and lower edge 33 of baffle 29 is approximately eight inches, which provides an opening height sufficient to accommodate substantially all briefcase type baggage. The present invention presents a variety of advantages over existing systems. First, the baffle encourages the proper placement of briefcase type baggage on the X-ray baggage inspection device conveyor. This allows the most thorough non-intrusive inspection of carry-on baggage. In addition, carry-on baggage that has a horizontal height that exceeds the preselected between the baffle and the conveyor surface may still pass unimpeded through the X-ray baggage inspection device, since the baffle will pivot inward in response to the conveyance of the baggage. Thus, the improper placement of baggage is discouraged, while baggage having a variety of configurations are passed through the X-ray baggage inspection device without impediment. The present invention saves a considerable amount of time at airport terminals, where improperly placed carry-on baggage impedes the flow of passengers and baggage through a terminal security station. In addition, the distraction and annoyance often associated with improperly positioned carry-on baggage is eliminated, allowing the X-ray baggage inspection device operator to focus his or her attention upon the task of detecting weapons and explosives. Although the invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that the appended claims will cover any such modifications or embodiments that fall within the true scope of the invention.
	claims	1. A method for acquiring a computed tomography (CT) image of a person's breast using a scanner system comprising:from a plurality of CT data sets of a plurality of persons, defining a plurality of different breast volume classes, each breast volume class corresponding to a different range of breast volume percentile groups;based on at least one of a shape and a size of the person's breast, assigning the person's breast to a breast volume class;from a plurality of immobilizers each corresponding to a different breast volume class, selecting an immobilizer corresponding to the breast volume class assigned to the person's breast;from a plurality of 3D-beam modulation filters each corresponding to a different breast volume class, selecting a 3D-beam modulation filter corresponding to the breast volume class assigned to the person's breast;coupling the selected immobilizer to the scanner system;positioning the person's breast in the selected immobilizer; andacquiring a computed tomography (CT) image of the person's breast using the scanner system with the selected 3D-beam modulation filter and the selected immobilizer,wherein each 3D-beam modulation filter has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through said person's breast. 2. The method of claim 1, wherein the selected 3D-beam modulation filter is configured to reduce a dose of radiation toward anterior and peripheral regions of the person's breast based on at least one of a shape and a size of the breast volume class assigned to the person's breast. 3. The method of claim 1, wherein acquiring the CT image of the person's breast further comprises:collecting x-rays beams emitted from an x-ray source of the scanner system on a detector panel of the scanner system, wherein the x-ray beams emitted by the x-ray source are filtered by the selected 3D-beam modulation filter prior to traveling through the person's breast. 4. The method of claim 1, further comprising:based on at least one of the shape and the size of the person's breast in addition to the assigned breast volume class, dynamically adjusting a position of the selected 3D-beam modulation filter between the person's breast and an x-ray source of the scanner system, prior to acquiring the computed tomography (CT) image of the person's breast. 5. The method of claim 1, further comprising:identifying a predetermined profile among a plurality of predetermined profiles based on the shape or size of the person's breast, wherein each of the plurality of 3D-beam modulation filters are generated for only one of the plurality of predetermined profiles, wherein each of the plurality of immobilizers are generated for only one of the plurality of predetermined profiles. 6. The method of claim 1 wherein the selected 3D-beam modulation filter comprises a combined filter, the method further comprising:selecting a bowtie-shaped filter among a plurality of bowtie-shaped filters based on the breast volume class assigned to the person's breast;selecting a wedge-shaped filter among a plurality of wedge-shaped filters based on the breast volume class assigned to the person's breast; andcombining the selected bowtie-shaped filter with the selected wedge-shaped filter into the combined filter. 7. The method of claim 1, wherein coupling the selected immobilizer to the scanner system further comprises:attaching a first end of an attachment element to a surface of the scanner system, andattaching second end of the attachment element to the selected immobilizer. 8. The method of claim 7, wherein the attachment element includes a flange or a fastener. 9. The method of claim 1, further comprising:acquiring two orthogonal scout views of the person's breast;adjusting a position of at least one of the 3D-beam modulation filter and the person's breast based on the acquired orthogonal scout views of the person's breast. 10. A computing device including a non-transitory storage medium storing instructions, and a processor executing the instructions stored on the non-transitory storage medium to perform the method of claim 1. 11. A computed tomography (CT) scanner system, comprising:an x-ray production system including an x-ray source configured to emit x-rays;an x-ray detector system constructed and arranged to receive the x-rays emitted by the x-ray source;a filter positioning system configured to select a 3D-beam modulation filter among a plurality of 3D-beam modulation filters each corresponding to a different breast volume class in a plurality of breast volume classes, said selected 3D-beam modulation filter corresponding to a breast volume class assigned to a body part to be imaged, said assigning based on at least one of a shape and a size of the body part, and further configured to position the selected 3D-beam modulation filter between the x-ray source and the x-ray detector system,wherein each 3D-beam modulation filter has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through the body part, andwherein said plurality of breast volume classes are defined from a plurality of CT data sets of a plurality of persons, each breast volume class corresponding to a different range of breast volume percentile groups; anda gantry assembly system including a table for receiving the body part. 12. The CT scanner system of claim 11 further comprising:a scanner control computer coupled to the x-ray production system and the gantry assembly system for sending control signals to the x-ray production system and the gantry assembly system. 13. The CT scanner system of claim 11, wherein the selected 3D-beam modulation filter comprises a combined filter, wherein the filter positioning system is further configured to:select a bowtie-shaped filter among a plurality of bowtie-shaped filters based on the volume class assigned to said body part;select a wedge-shaped filter among a plurality of wedge-shaped filters based on the volume class assigned to said body part; andcombine the selected bowtie-shaped filter and the selected wedge-shaped filter into the combined filter. 14. The CT scanner system of claim 11 further comprising:an image acquisition computer for receiving image data from the x-ray detector system;an image reconstruction computer for reconstructing a CT image of the body part based on the image data received from the image acquisition computer; anda display for displaying the reconstructed CT image of the body part. 15. The CT scanner system of claim 14, wherein the image reconstruction computer receives data from a scanner control computer and the image acquisition computer, the data including at least one of x-ray beam intensity data, x-ray beam emission timing data, gantry assembly system positioning data, and projection images of the body part being imaged. 16. The CT scanner system of claim 11, wherein the body part is a breast and the selected 3D-beam modulation filter is configured to reduce a dose of radiation toward anterior and peripheral regions of the breast based on at least one of a shape and a size of the volume class assigned to the breast. 17. The CT scanner system of claim 11, further comprising an immobilizer coupled to the gantry assembly system, wherein the immobilizer is coupled to the gantry assembly system using one or more attachment elements. 18. The CT scanner system of claim 11, further comprising an immobilizer selection system configured to select a breast immobilizer from a plurality of breast immobilizers, each breast immobilizer corresponding to a different breast volume class out of the plurality of breast volume classes, each immobilizer structured to be connectable to and disconnectable from said table. 19. The CT scanner system of claim 18, further comprising said plurality of breast immobilizers. 20. The CT scanner system of claim 18, wherein the immobilizer selection system is further configured to position the person's breast in the selected immobilizer and perform a check for the immobilizer fit with a laser-based system. 21. The CT scanner system of claim 11, further comprising said plurality of 3D-beam modulation filters. 22. The CT scanner system of claim 11, wherein said filter positioning system is further configured to receive scout view data of the body part and to dynamically a position of at least one of the selected 3D-beam modulation filter and the body part, based on the scout view data and at least one of the shape of the body part, the size of the body part, and the assigned breast volume class. 23. The CT scanner system of claim 22, wherein said scout view data is x-ray scout view data. 24. The CT scanner system of claim 22, wherein said scout view data is optical scout view data. 25. The CT scanner system of claim 11, further comprising a laser-evaluating system configured to determine the breast volume class that best fits the person's breast. 26. A cone-beam breast computed tomography (CT) system, comprising:a table arranged to support a person to lie prone with the person's breast extending through an aperture defined by the table;a plurality of breast immobilizers, each corresponding to a different breast volume class out of a corresponding plurality of breast volume classes, each breast immobilizer structured to be connectable to and disconnectable from said table at said aperture to immobilize said person's breast when it extends through said aperture;a gantry disposed proximate to said table;a cone-beam x-ray source attached to said gantry and positioned to be able to irradiate said person's breast with a cone beam of x-rays;a plurality of modulation filters, each corresponding to one of said plurality of breast volume classes, and each adapted to be connected to and disconnected from said gantry at a position between said cone-beam x-ray source and said person's breast; anda flat-panel detector attached to said gantry and positioned to be able to receive at least a portion of said cone beam of x-rays after passing through said person's breast,wherein said gantry is rotatable about an axis that intercepts said person's breast such that said cone-beam x-ray source and said flat-panel detector rotate with said gantry in unison, andwherein said plurality of breast volume classes are defined from a plurality of CT data sets of a plurality of persons, each breast volume class corresponding to a different range of breast volume percentile groups, andwherein at least one modulation filter of said plurality of modulation filters is a 3D-beam modulation filter that has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through said person's breast. 27. The cone-beam breast computed tomography (CT) system according to claim 26,wherein each said modulation filter compensates for different x-ray path lengths through different portions of said person's breast of the corresponding breast volume class to reduce a total amount of x-ray dose,wherein each said modulation filter, when connected to said gantry, is rotatable with said gantry in unison with said cone-beam x-ray source and said flat-panel detector. 28. An accessory kit for a cone-beam breast computed tomography (CT) system, comprising:a plurality of breast immobilizers, each corresponding to a different breast volume class out of a corresponding plurality of breast volume classes, and each being structured to be connectable to and disconnectable from a table of said cone-beam breast CT system at an aperture defined by said table; anda plurality of modulation filters, each corresponding to a different breast volume class out of the corresponding plurality of breast volume classes, and each adapted to be connected to and disconnected from a gantry at a position between a cone-beam x-ray source and said person's breast,wherein the plurality of breast volume classes are defined from a plurality of CT data sets of a plurality of persons, each breast volume class corresponding to a different range of breast volume percentile groups,wherein each breast immobilizer is configured to immobilize a person's breast when it extends through said aperture, andwherein at least one modulation filter of said plurality of modulation filters is a 3D-beam modulation filter that has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through said person's breast. 29. The accessory kit according to claim 28, further comprising:wherein each said modulation filter compensates for different x-ray path lengths through different portions of said person's breast of the corresponding breast volume class to reduce a total amount of x-ray dose,wherein each said modulation filter, when connected to said gantry, is rotatable with said gantry in unison with said cone-beam x-ray source and a flat-panel detector. 30. An accessory kit for a cone-beam breast computed tomography (CT) system, comprising:a plurality of modulation filters, each corresponding to a different breast volume class out of a corresponding plurality of breast volume classes, and each adapted to be connected to and disconnected from a gantry at a position between a cone-beam x-ray source and a person's breast,wherein the plurality of breast volume classes are defined from a plurality of CT data sets of a plurality of persons, each breast volume class corresponding to a different range of breast volume percentile groups,wherein each said modulation filter compensates for different x-ray path lengths through different portions of said person's breast of the corresponding breast volume class to reduce a total amount of x-ray dose,wherein each said modulation filter, when connected to said gantry, is rotatable with said gantry in unison with said cone-beam x-ray source and a flat-panel detector, andwherein at least one modulation filter of said plurality of modulation filters is a 3D-beam modulation filter that has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through said person's breast. 31. The accessory kit according to claim 30, wherein each modulation filter of said plurality of modulation filters comprises a first filter for filtering along a first dimension and a second filter for filtering along a second dimension that is orthogonal to the first dimension. 32. The accessory kit according to claim 31, wherein at least one of said first filter or said second filter is formed from titanium.
044144750	summary	The invention relates to a shielding container for storing weak to medially active waste in a storage barrel or drum which is surrounded by the shielding container. Shielding containers of this type, such as those shown in German Published, Non-Prosecuted Application DE-OS 27 16 463 and German Petty Patent DE-GM 77 36 411, have heretofore been provided for permanent connection with the storage barrel, because the shielding container which was made in the form of a concrete pot was closed after insertion of the storage barrel by a concrete plug which was cast on top. This means that the volume and weight of the prior art shielding containers had to be also considered during a later transport and especially during the final storage. It is accordingly an object of the invention to provide a shielding container for storing weak to medially active wase, which overcomes the hereinafore-mentioned disadvantages of the heretofore known devices of this general type, and to obtain the shielding effect achieved by the known shielding containers only when required. The starting point is therefore the fact that the previously used final storage means are closed, so that the radioactive wastes must be in an intermediate storage facility, especially at the location where they are generated at least temporiarly. However, in nuclear power plants only relatively little space is available for this purpose, so that it is necessary to effect the storage in the most compact form. On the other hand, it is not permissible to "plug-up" the available space for long periods of time, or permanently. Rather, only a temporary storage is intended, until final storage facilitates are available, similar to previously used disposal in the abandoned salt mine Asse. With the foregoing and other objects in view there is provided, in accordance with the invention, a shielding container assembly for storing weak to medially active waste in a storage barrel, comprising a shielding container having a substantially or mainly square cross section surrounding the storage barrel, the shielding container having two pairs of oppositely-disposed sections or sides, one of the pairs having symmetrical projections formed thereon and the other of the pairs having chamfers formed thereon, and projections and chamfers effecting anchoring or interlocking of the containers when stacked close to each other. With shielding containers of this type, it becomes possible to fill the storage rooms in a much better way than with the known concrete pots which have a cylindrical outer shape. This applies not only for the stacking itself, but also for the strength achieved thereby, which, for example, must be capable of withstanding the lateral forces created by a possible earthquake. Furthermore, the shielding containers according to the invention can be used without a tight connection to the storage drums, because the required mechanical holding is provided by the new configuration of the cross section. In accordance with another feature of the invention, the projections and chamfers are disposed at corners of the shielding container. In accordance with a further feature of the invention, the projections and chamfers are in the form of symmetrical pairs. In accordance with an added feature of the invention, the shielding container has a clearance space or opening therein for receiving the storage barrel, the space extending through the total height of the shielding container. They can be assembled to form a stack without the storage drums, and can be filled with the storage drums. This facilitates handling, because the transport-weights are much less. In accordance with an additional feature of the invention, the clearance space has a cylindrical cross section and is centrally disposed in the substantially square cross section of the shielding container. In accordance with again another feature of the invention, the shielding container has top and bottom surfaces thereon, the surfaces having raised portions formed thereon and having recesses formed therein into which the raised portions fit. This is done because it makes it possible to also stack the shielding containers in a formation having severakl layers high on top of each other. In accordance with again a further feature of the invention, the raised portions are disposed at four corners of the square cross section of the shielding container. In accordance with again an added feature of the invention, the shielding container has undercuts formed therein, optionally at the recesses for attachment of gripper tools. In accordance with again an additional feature of the invention, there are provided reinforcements being disposed in the undercuts and extended into the shielding container, so that they are securely anchored there. In accordance with a concomitant feature of the invention, there is provided a storage chamber having straight walls with recesses formed therein, the projections being extended into the recesses. In this way an anchoring with respect to the building itself is achieved. The stacked shielding containers are thereby well anchored against lateral forces, such as forces generated by an earthquake. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as embodied in a shielding container for storing weak to medially active waste, it is nevertheless not included to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
047553499	claims	1. In a nuclear reactor having a pump and a dome, an improved anti-seismic connection between a base of the pump and the dome, said connection being characterized in that it includes a socket closed by a fixedly attached cover and axially slidably disposed within a cylindrical portion of said dome, said pump base has an exterior flange received within said socket with relatively large radial play and relatively small axial play, radial damping means is provided between said flange and said socket to freely permit relatively slow radial movements of said flange with respect to said socket due to effects such as differential thermal expansion between elements of the reactor but to block relatively rapid radial displacements of said flange with respect to said socket due to effects such as earthquakes, a lower end of said socket has a collar provided with a metallic journal axially slidable within a cylindrical bearing solidly fixed to an internal lateral wall of said dome, and calibrated passages are arranged at the periphery of said socket to permit controlled circulation of heat-carrying fluid of the reactor between said pump base and said dome. 2. A connection according to claim 1, characterized in that said radial damping means comprises a damper ring surrounding said flange within said socket, said damper ring is movable in a radial direction within said socket, and said flange is movable in a radial direction within said damper ring. 3. A connection according to claim 2, characterized in that said damper ring has angularly spaced projections each bearing on a corresponding surface of the periphery of said flange or an inner peripheral wall of said socket, said projections delimiting damping fluid chambers. 4. A connection according to claim 3, characterized in that each projection has a flat end surface which bears on the said corresponding surface, said corresponding surface also being flat. 5. A connection according to claim 4, characterized in that said projections are alternately disposed interiorly and exteriorly around the circumference of said damper ring. 6. A connection according to claim 5, characterized in that there are four of said projections disposed at 90.degree. angles about the circumference of said damper ring. 7. A connection according to claim 1, characterized in that said radial damping means comprises a plurality of dashpots angularly spaced around said flange, each dashpot having one end acting on said socket and another end acting on said flange. 8. A connection according to claim 7, characterized in that there are four of said dashpots disposed at 90.degree. angles about said flange. 9. A connection according to claim 7, characterized in that said dashpots have respective cylinders at least partially disposed in cavities in said flange. 10. In a nuclear reactor having a pump and a dome, an anti-seismic connection between a base of said pump and said dome having, in combination, an external flange provided upon said pump base seated with relatively small axial play and with relatively large radial play within a socket closed by a fixedly attached cover and capable of sliding axially within a reinforced cylindrical portion of said dome, and radial damping means disposed between said flange and said socket for permitting relatively slow radial displacements between said flange and said socket due to effects such as differential thermal expansion between elements of the reactor and for blocking relatively abrupt radial displacements therebetween due to seismic disturbances, the lower end of said pump base being surrounded by a collar having a journal axially slidable within a bearing solidly fixed to an internal wall of said dome. 11. A connection according to claim 10, characterized in that said radial damping means comprises a damper ring disposed between said flange and said socket, with respective damping fluid chambers being interposed between portions of said ring and said socket and between portions of said flange and said ring. 12. A connection according to claim 10, characterized in that said radial damping means includes a plurality of angularly spaced dashpots acting radially upon said flange and said socket. 13. In a nuclear reactor having a pump and a dome, an anti-seismic connection between a base of said pump and said dome, said connection comprising socket means axially slidable within a portion of said dome, an external flange of said pump base received within said socket means axially movable with said socket means within said portion of said dome and radially movable within said socket means, radial fluid damping means between said flange and said socket means for permitting substantially unconstrained relatively slow radial movements of said flange within said socket means due to effects such as differential thermal expanision between elements of said reactor and for blocking relatively rapid radial movements of said flange within said socket means due to seismic disturbances, and axial fluid damping means including fluid passages formed in said socket means for permitting substantially unconstrained relatively slow axial movements of said socket means within said portion of said dome due to said effects such as differential thermal expansion and for blocking relatively rapid axial movements of said socket means within said portion of said dome due to said seismic disturbances. 14. A connection according to claim 13, characterized in that said socket means includes a circumferential collar surrounding said pump base and axially slidable within a circumferential bearing surface solidly fixed to said dome. 15. A connection according to claim 14, characterized in that said collar has a peripheral journal slidably disposed against said bearing surface. 16. A connection according to claim 15, characterized in that said fluid passages include passages formed in said journal and in an outer peripheral portion of said socket means in which said flange is received. 17. A connection according to claim 13, characterized in that said radial damping means includes a damper ring surrounding said flange within said socket means, said damper ring is radially movable within said socket means, and said flange is radially movable within said damper ring. 18. A connection according to claim 17, characterized in that said damper ring has diametrically opposed external first projection means slidably engaging diametrically opposite internal flats of said socket means, said flange has diametrically opposed external second projection means oriented substantially at 90.degree. to said first projection means and slidably engaging internal peripheral flats of said damper ring, said first projection means delimit diametrically opposed fluid chambers between said damper ring and said socket means, and said second projection means delimit diametrically opposed fluid chambers between said damper ring and said flange. 19. A connection according to claim 18, characterized in that said first and second projection means have flat surfaces slidably engaging the corresponding flats of said socket means and said damper ring. 20. A connection according to claim 13, characterized in that said radial damping means includes a plurality of dashpots acting radially upon said flange and said socket means.
	description	Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the embodiments set forth below, an X-ray stepper in which a mask pattern is transferred to a wafer by a step-and-repeat operation will be described. However, the present invention is not limited to the following embodiments. First Embodiment Reference will be had to FIGS. 1 and 2 to describe an X-ray exposure apparatus according to first embodiment of the present invention. FIG. 1 is a schematic view illustrating an X-ray exposure apparatus according to a first embodiment of the present invention as seen from the side, and FIG. 2 is a schematic view illustrating the X-ray exposure apparatus according to this embodiment as seen from above. The apparatus includes a point-source X-ray source 101 that uses a solid metal target (not shown) and condenses laser light (not shown) to apply the laser light to the target in the form of pulses. The metal surface thus irradiated with the laser light is plasmatized and produces X-rays. The intensity and pulse width with respect to time of the laser light can be controlled by an intensity adjustment mechanism in the laser oscillator, not shown. By varying the intensity and pulse width with respect to time of the laser light using the intensity adjustment mechanism, the point-source X-ray source 101 is capable of controlling the intensity of the X-rays generated. In this X-ray exposure apparatus, the X-rays emitted by the point-source X-ray source 101 are introduced into a first collimator 110, second collimator 120 and third collimator 130. The centers of these three collimators 110 to 130 are disposed so as to have the same Z coordinate in the XYZ coordinate system of the drawings. The second collimator 120 uses X-rays in an area A as its input and the third collimator 130 uses X-rays in an area C as its input. Since the three collimator 110 to 130 in this case are disposed in a radial configuration with respect to the X-ray emission point of the point-source X-ray source 101, substantially the same design can be adopted for them. It is essential that the laser and target of the point-source X-ray source 101 be so disposed as not to interfere with an X-ray introduction chamber 102 and first, second and third exposure units 119, 129, 139, respectively. In the X-ray exposure apparatus of this embodiment, the first, second and third exposure units 119, 129, 139 are connected to the first, second and third collimators 110, 120, 130, respectively. In the first exposure unit 119, a first mask 113 and first wafer 114 are placed so that their angles will conform approximately to the emission angle of the first collimator 110. The same is true with regard to the second exposure unit 129 and third exposure unit 139. In each of the exposure units 119, 129, 139, precise angular and positional adjustments between the optical axis of exposure and the masks 113, 123, 133 and wafers 114, 124, 134 is carried out by moving the exposure units 119, 129, 139, per se, or the collimators 110,120, 130. In the first exposure unit 119, the first mask 113 is brought in and sent out between a mask introduction section (not shown) and the exterior of the first exposure unit 119 by means of the mask introduction selection. The first mask 113 introduced to the first exposure unit 119 is delivered to a mask stage (not shown) by a mask transport system (not shown). The same is true with regard to the second exposure unit 129 and third exposure unit 139. Further, in the first exposure unit 119, the first wafer 114 is brought in and seat out between a wafer introduction section (not shown) and the exterior of the first exposure unit 119, by means of the wafer introduction section. The first wafer 114 introduced to the first exposure unit 119 is delivered to a first wafer stage 16 by a wafer transport system (not shown). The same holds true for the second exposure unit 129 and third exposure unit 139. The first wafer stage 116, second wafer stage 126 and third wafer stage 136 are guided along respective ones of guides by gas bearings that employ helium gas. Position information concerning the wafer stages 116, 126, 136 is measured by laser interferometers (not shown) and the stages are driven by linear motors (not shown) based upon the measurements obtained. The first mask 113 is positioned with respect to a reference mark in the first exposure unit 119 by a position detector and mask stage, neither of which are shown. The first mask 113 and first wafer 114 are positioned relative to each other by the position detector and mask stage (not shown) and by the first wafer stage 116. The second mask 123 and third mask 133 are positioned in the same manner. A method of controlling the X-ray exposure apparatus according to this embodiment will now be described with reference to FIGS. 3 and 4, in which FIG. 3 is a control block diagram of the X-ray exposure apparatus according to this embodiment and FIG. 4 is a diagram of control timing of the X-ray exposure apparatus according to this embodiment. The emission timing of the laser in a point-source X-ray source 301, namely, the X-ray emission timing, is decided by an X-ray emission trigger signal. Further, the point-source X-ray source 301 is such that the intensity of the emitted laser is decided by an X-ray intensity control signal. It is preferred that the X-ray emission trigger signal and X-ray intensity control signal be signals of the kind shown in FIG. 4. Whether X-rays are capable of being emitted, and the internal device status, are constantly reported by the point-source X-ray source 301 to an exposure-apparatus total control unit 304 as a point-source X-ray source status signal. A target value of an amount of exposure by the first exposure unit is set in the total control unit 304. The set value is transmitted to a first exposure-amount controller 306. The same is true with regard to the second and third exposure units. The total control unit 304 calculates target values of X-ray intensity and emission pulse count based upon the set value of an amount of exposure. The total control unit 304 notifies an X-ray intensity control signal generator 303 of the X-ray intensity prevailing when the exposure is started, and the X-ray intensity control signal generator 303 sets the X-ray intensity control signal to a prescribed value. This control signal is set to prescribed values by the signal and timings shown in FIG. 4 and is output from the point-source X-ray source 301 to the X-ray intensity control signal generator 303. When preparations for exposure of a shot to be exposed are completed in the first exposure unit, the first exposure unit controller 306 so notifies the total control unit 304. Alternatively, if the first exposure unit is not scheduled to perform exposure for the time being, the first exposure unit controller 306 notifies the total control unit 304 that the first exposure unit is idle. Operation is the same with regard to the second and third exposure units. When all of the first to third exposure units are ready to perform exposure or are idle, the total control unit 304 sends a shutter controller 305 a command to open the shutter (first shutter 35, second shutter 36 or third shutter 317) corresponding to the exposure unit that is ready to perform exposure. In other words, a shutter corresponding to an exposure unit in the idle state is left closed. In this embodiment, the timings shown in FIG. 4 are adopted as an example of timings of the exposure states (exposure ON/exposure OFF) of the first to third exposure units and timings of the states (open/closed) of the first to third shutters. Since an exposure unit in the idle state does not undergo control of an amount of exposure, the description rendered below assumes that none of the exposure units are idle. The shutter controller 305 causes first, second and third shutter drive units 312, 313 and 314, respectively, to exercise control so as to open the first, second and third shutters 315, 316 and 317, respectively, whereby the shutters 315, 316, 317 are driven by the shutter driver units 313, 313, 314, respectively. Upon confirming that opening of the shutters 315, 316, 317 is completed, the first through third shutter drive units 312 to 314 so notify the shutter controller 305. Upon being so notified, the shutter controller 305 similarly notifies the exposure-apparatus total control unit 304. The exposure-apparatus total control unit 304 receives signals giving notification of the status of the point-source X-ray source, notification of completion of shutter opening and notification that the first to third exposure units are ready to perform exposure. Upon judging that exposure is possible based upon these notification signals, the total control unit 304 starts the exposure operation. At this time, the total control unit 304 issues a trigger generation command to an X-ray emission trigger generating unit 302. The latter outputs an X-ray emission trigger signal to the point-source X-ray source 301. The X-ray emission trigger signal is output as the pulsed signal and at the timings shown in FIG. 4, by way of example. The first exposure unit controller 306 measures the X-ray intensity by a first X-ray sensor 309, thereby obtaining an integrated value from the start of exposure of the first shot. The exposure-apparatus total control unit 304 reads the integrated value of X-ray intensity out of the first exposure unit controller 306 for every X-ray emission pulse. The total control unit 304 notifies the X-ray intensity control signal generator 303 to lower the X-ray intensity if the integrated value of X-ray intensity of the first exposure unit has approached the target value of the amount of exposure and the difference between them has fallen below a certain threshold value. As a result, the error between the target value of the amount of exposure and the actual amount of exposure of one shot in the first exposure unit diminished. These operations are the same with regard to the second exposure unit controller 307 and second X-ray sensor 310 and with regard to the third exposure unit controller 308 and third X-ray sensor 311. If X-ray intensity is controlled across the board in the above method, there is the possibility that an error in the amount of exposure will take on a large value because the target value has already been reached or because of the other exposure units whose integrated target values of the amount of exposure are nearly the same. In order to prevent this, the total control unit 304 has adjustment means for varying the threshold value, which is used in evaluating the error, in conformity with the target value of the amount of exposure of each exposure unit. With regard to the first exposure unit controller 306, the total control unit 304 judges the error in the amount of exposure in the first exposure unit from the target value of X-ray intensity of the next pulse and performs a calculation, pulse by pulse, to determine whether the error is the minimum error. If it is determined that the exposure error is minimum, then the exposure-apparatus total control unit 304 sends the shutter controller 305 a command to close the first shutter 315, thereby terminating exposure of one shot. These operations are the same with regard to the second exposure unit controller 307 and third exposure unit controller 308. In this embodiment, three exposure units are provided. However, the present invention is not limited to three exposure units. Two or more exposure units may be used and there is no limit upon the number of exposure units so long as this number of units can be installed. Second Embodiment A second embodiment of the present invention will now be described. FIG. 5 is a schematic view illustrating an X-ray exposure apparatus according to this embodiment, in which components identical with those shown in the FIGS. 1 and 2 are designated by like reference characters. As shown in FIG. 5, a fourth exposure unit 149, fourth collimator 140, fifth exposure unit 159 and fifth collimator 150 can be provided in addition to the first to third exposure units and first to third collimators of the first embodiment. These additional exposure units and collimators are disposed along the Z-axis. This embodiment makes it possible to raise the utilization efficiency of the X-ray source even further. Third Embodiment A third embodiment of the present invention will now be described. In this embodiment, all or part of the wafer transport system, which is for supplying wafers to each of the exposure units and ejecting wafers whose exposure has been completed, can be shared by each of the first to third exposure units of the first embodiment and by each of the first to fifth exposure units of the second embodiment. Further, all or part of the system for transporting masks or masks on which circuit patterns have been rendered for being burned into wafers can be shared by each of the first to third exposure units of the first embodiment and by each of the first to fifth exposure units of the second embodiment. Fourth Embodiment A fourth embodiment of the present invention will now be described. In each of the foregoing embodiments, the shots of n-number of exposure units start to be exposed simultaneously. An X-ray exposure apparatus using an exposure timing other than this will be described in this embodiment. In FIG. 3, the exposure-apparatus total control unit 304 can exercise control in such a manner that the exposure timings of the n exposure units are made to conform to particular objectives. Examples of these objectives are an improvement in the utilization efficiency of the X-ray source, a reduction in exposure processing time and suppression of a decline in precision caused by vibration between exposure units. In order to achieve the above, the X-ray exposure apparatus according to this embodiment sets a redundancy-allowance threshold value Tth of exposure processing time and redundancy-allowance threshold value of Pth of X-ray source pulses in the exposure apparatus total control unit 304 beforehand. In a range within which these two threshold values are not exceeded, the X-ray exposure apparatus of this embodiment is capable of tuning exposure timing in accordance with the above-objectives. In this embodiment, control of the amount of exposure of each shot is carried out by controlling both the number of exposure pulses and the X-ray intensity of the X-ray source in a manner similar to that described in the first embodiment. Further, the requirements concerning exposure processing time and the requirements concerning utilization efficiency of the X-ray source are decided depending upon the aim at the time the apparatus is utilized. These requirements need only be decided based upon the particular priority. Embodiment of a Semiconductor Production System Described next will be an example of a system for producing semiconductor devices (e.g., semiconductor chips such as IC and LSI chips, liquid crystal panels, CCDs, thin-film magnetic heads and micromachines, etc.) utilizing the X-ray exposure apparatus described above. This system utilizes a computer network outside the semiconductor manufacturing plant to provide troubleshooting and regular maintenance of manufacturing equipment installed at the manufacturing plant and to furnish maintenance service such as the provision of software. FIG. 6 illustrates the overall system as seen from a certain angle. As shown in FIG. 6, the system includes the business office 601 of the vendor (equipment supplier) that provides the equipment for manufacturing semiconductor devices. Semiconductor manufacturing apparatus for performing various processes used in a semiconductor manufacturing plant is assumed to be an actual example of the manufacturing apparatus. Examples of the apparatus are pre-treatment apparatus (e.g., lithographic apparatus such as exposure apparatus, resist treatment apparatus and etching apparatus, heat treatment apparatus, thin-film apparatus and smoothing apparatus, etc.) and post-treatment apparatus (e.g., assembly apparatus and inspection apparatus, etc.). The business office 601 includes a host management system 608 for providing a manufacturing-apparatus maintenance database, a plurality of control terminal computers 610, and a local-area network (LAN) 609 for connecting these components into an intranet. The host management system 608 has a gateway for connecting the LAN 609 to the Internet 605, which is a network external to the business office 601, and a security function for limiting access from the outside. Numerals 602 to 604 denote manufacturing plants of semiconductor makers (e.g., semiconductor device makers), which are the users of the manufacturing apparatus. The manufacturing plants 602 to 604 may be plants belonging to makers that differ from one another or plants belonging to the same maker (e.g., pre-treatment plants and post-treatment plants, etc.). Each of the plants 602 to 604 is provided with a plurality of manufacturing apparatus 606, a local-area network (LAN) 611, which connects apparatus to construct an intranet, and a host management system 607 serving as a monitoring unit for monitoring the status of operation of each manufacturing apparatus 606. The host management system 607 provided at each of the plants 602 to 604 has a gateway for connecting the LAN 611 in each plant to the Internet 605 serving as the external network of the plants. As a result, it is possible for the LAN of each plant to access the host management system 608 on the side of the vendor 610 via the Internet 605. By virtue of the security function of the host management system 608, users allowed to access the host management system 608 are limited. More specifically, status information (e.g., the condition of manufacturing apparatus that has malfunctioned), which indicates the status of operation of each manufacturing apparatus 606, can be reported from the plant side to the vendor side. In addition, information in response to such notification (e.g., information specifying how to troubleshoot the problem, troubleshooting software and data, etc.), as well as the latest software and maintenance information such as help information, can be acquired from the vendor side. A communication protocol (TCP/IP), which is used generally over the Internet, is employed for data communication between the plants 602xcx9c604 and the vendor 601 and for data communication over the LAN 611 within each plant. Instead of utilizing the Internet as the external network of a plant, it is also possible to utilize a highly secure leased-line network (e.g., an ISDN, for example) that cannot be accessed by a third party. Further, the host management system is not limited to that provided by a vendor, for an arrangement may be adopted in which the user constructs a database, places it on an external network and allows the database to be accessed from a number of plants that belong to the user. FIG. 7 is a conceptual view illustrating the overall system of this embodiment as seen from an angle different from that depicted in FIG. 6. In the earlier example, a plurality of user plants each having manufacturing apparatus are connected by an external network to the management system of the vendor that provided the manufacturing apparatus, and information concerning the production management of each plant and information concerning at least one manufacturing apparatus is communicated by data communication via the external network. In the example of FIG. 7, on the other hand, a plant having a manufacturing apparatus provided by a plurality of vendors is connected by an outside network to management systems of respective ones of the vendors of these plurality of manufacturing apparatus, and maintenance information for each manufacturing apparatus is communicated by data communication. As shown in the drawing, the system includes a manufacturing plant 701 of the user of the manufacturing apparatus, (e.g., the maker of semiconductor devices). The manufacturing line of this plant includes manufacturing apparatus for implementing a variety of processes. Examples of such apparatus are an exposure apparatus 702, a resist treatment apparatus 703 and a thin-film treatment apparatus 704. Though only one manufacturing plant 701 is shown in FIG. 7, in actuality, a plurality of these plants are networked in the same manner. The apparatus in the plant are interconnected by a LAN 706 to construct an intranet and the operation of the manufacturing line is managed by a host management system 705. The business offices of vendors (e.g., equipment suppliers) such as an exposure apparatus maker 710, a resist treatment apparatus maker 720 and a thin-film apparatus equipment maker 730 have host management systems 711, 721, 731, respectively, for remote maintenance of the apparatus they have supplied. These have maintenance databases and gateways to the outside network, as described earlier. The host management system 705 for managing each apparatus in the manufacturing plant of the user is connected to the management systems 711, 721, 731 of the vendors of these apparatus by the Internet or leased-line network serving as an external network 700. If any of the series of equipment in the manufacturing line malfunctions, the line ceases operating. However, this can be dealt with rapidly by receiving remote maintenance from the vendor of the faulty equipment via the Internet 700, thereby making it possible to minimize line downtime. Each manufacturing apparatus installed in the semiconductor manufacturing plant has a display, a network interface and a computer for executing network-access software and equipment operating software stored in a storage device. The storage device can be an internal memory or hard disk or a network file server. The software for network access includes a special-purpose or general-purpose Web browser and presents a user interface, which has a screen of the kind shown by way of example in FIG. 8, on the display. The operator managing the manufacturing equipment at each plant enters information at the input items on the screen while observing the screen. The information includes model 801 of the manufacturing apparatus, its serial number 802, subject matter 803 of the problem, its date of occurrence 804, degree of urgency 805, the particular condition 806, countermeasure method 807 and progress report 808. The entered information is transmitted to the maintenance database via the Internet. The resulting appropriate maintenance information is sent back from the maintenance database and is presented on the display screen. The user interface provided by the Web browser implements hyperlink functions 810, 811, 812 as illustrated and enables the operator to access more detailed information for each item, to extract the latest version of software, which is used for the manufacturing equipment, from a software library provided by the vendor, and to acquire an operating guide (help information) for reference by the plant operator. Accordingly, the maintenance information provided by the maintenance database also includes information relating to the present invention described above, and the software library also provides the latest software for implementing the present invention. A process for manufacturing a semiconductor device utilizing the production system set forth above will now be described. FIG. 9 illustrates the overall flow of a process for manufacturing semiconductor devices. The circuit for the device is designed at step 1 (circuit design). A mask on which the designed circuit pattern has been formed is fabricated at step 2 (mask fabrication). Meanwhile, a wafer is manufactured using a material such as silicon or glass at step 3 (wafer manufacture). The actual circuit is formed on the wafer by lithography, using the mask and wafer that have been prepared, at step 4 (wafer process), which is also referred to as xe2x80x9cpre-treatmentxe2x80x9d. A semiconductor chip is obtained, using the wafer fabricated at step 4, at step 5 (assembly), which is also referred to as xe2x80x9cpost-treatmentxe2x80x9d. This step includes steps such as actual assembly (dicing and bonding) and packaging (chip encapsulation). The semiconductor device fabricated at step 5 is subjected to inspections such as an operation verification test and a durability test, at step 6 (inspection). The semiconductor device is completed through these steps and then is shipped (step 7). The pre- and post-treatments are performed at separate special-purpose plants. Maintenance is carried out on an a per-plant basis by the above-described remote maintenance system. Further, information for production management and equipment maintenance is communicated by data communication between the pre- and post-treatment plants via the Internet or leased-line network. FIG. 10 is a flowchart illustrating the detailed flow of the wafer process mentioned above. The surface of the wafer is oxidized at step 11 (oxidation). An insulating film is formed on the wafer surface at step 12 (CVD), electrodes are formed on the wafer by vapor deposition at step 13 (electrode formation), and ions are implanted in the wafer at step 14 (ion implantation). The wafer is coated with a photoresist at step 15 (resist treatment), the wafer is exposed to the circuit pattern of the mark to print the pattern onto the wafer by the above-described exposure apparatus at step 16 (exposure), and the exposed wafer is developed at step 17 (development). Portions other than the developed photoresist are etched away at step 18 (etching), and unnecessary resist left after etching is performed is removed at step 19 (resist removal). Multiple circuit patterns are formed on the wafer by implementing these steps repeatedly. Since the manufacturing equipment used at each step is maintained by the remote maintenance system described above, malfunctions can be prevented and quick recovery is possible if a malfunction should happen to occur. As a result, the productivity of semiconductor device manufacture can be improved over the prior art. Thus, in accordance with the present invention as described above, it is possible to provide an X-ray exposure apparatus in which the energy of the X-rays emitted by an X-ray source can be utilized in a highly efficient manner. Further, the number of X-ray sources (light sources) can be reduced with respect to a plurality of collimators and plurality of exposure means disposed in the X-ray exposure apparatus of the present invention. This makes it possible to lower cost and reduce installation space. In addition, labor involved in maintaining the X-ray source can be reduced in comparison with the X-ray exposure apparatus of the prior art. As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the claims.
	description	This application is a continuation application of U.S. Ser. No. 14/612,461, filed Feb. 3, 2015, entitled APPARATUS FOR DEGASSING A NUCLEAR REACTOR COOLANT SYSTEM. 1. Field The present invention relates generally to a process for removing dissolved gasses from reactor coolant in a nuclear power plant and more particularly to apparatus for removing dissolved hydrogen and fission gases from the reactor coolant by passing the coolant over a membrane and extracting the gasses by applying a vacuum. 2. Related Art During pressurized water reactor plant shutdowns, it is a common practice to drain the reactor coolant system to a level below the reactor vessel flange to the mid-plane of the reactor vessel coolant outlet nozzles. That mid-plane coincides with the mid-plane of the connecting “hot leg” piping leading to the steam generators. This drain-down permits inspection, testing and maintenance, during shutdown, of pumps, steam generators, support structures and other primary system components. During reactor operation, some fission gases, e.g., xenon and krypton, created by the fission reactions occurring in the nuclear fuel, may enter the reactor coolant system and become dissolved in the reactor coolant. Subsequent to shut down, but before refueling and maintenance operations commence, the concentration of radioactive gases and hydrogen must be reduced to avoid excessive radiation exposure to plant maintenance inspection personnel and reduce the likelihood of an explosion due to a potential spark setting off a flammable mixture of air and hydrogen in the containment atmosphere. Reactor coolant has previously been degassed using a volume control tank connected to the reactor coolant system. Generally, the reactor coolant system primarily includes such nuclear steam supply system components as the reactor vessel, the steam generators, the reactor coolant pumps and the connecting piping. The volume control tank is part of the system known as the chemical and volume control system which operates in the degassing mode by flashing the dissolved hydrogen and radioactive gases out of the reactor coolant and into the vapor space of the volume control tank. An example of such a system could be found in U.S. Pat. No. 4,647,425. Typically, a relatively small flow of reactor coolant referred to as the letdown flow is diverted from the reactor coolant system and through the chemical and volume control system. This stream is first cooled then purified in a mixed bed demineralizer, filtered to remove dissolved ionic or suspended particulate material and passed to the volume control tank. U.S. Pat. No. 4,647,425 proposes an improvement to this chemical and volume control system procedure and reduces the time required to effectively degas the reactor coolant. The method proposed by the patent provides for vacuum degassing a reactor coolant system. The method comprises draining down the reactor coolant system to approximately the mid-point of the hot leg and maintaining the reactor coolant system in an unvented condition during the drain-down operation. Any flashed reactor coolant in the primary side of the steam generator is then refluxed. As used in the above mentioned patent, flashed reactor coolant means liquid coolant which flashes into the steam phase as a result of lower ambient pressure. Refluxed means condensed and cooled. The bulk of the reactor coolant as well as the refluxed reactor coolant, are circulated through a residual heat removal system to cool the reactor coolant. A vacuum is drawn on the reactor coolant system to evacuate any gas stripped from the reactor coolant. Preferably, the step of draining the coolant system establishes a partial vacuum in the unvented reactor vessel and reactor coolant system during drain-down. The partial vacuum is sufficient to cause the reactor coolant to boil at the prevailing temperatures in the reactor coolant system whereby the degassing occurs during the drain-down step. FIG. 1 shows one prior art embodiment of a vacuum degassing system 10 that is currently in use. The letdown flow enters the system at the inlet 12 and is directed to an inlet 14 of a degasifier column vessel 16 where it enters the interior of the vessel through a spray head 18. A vacuum is drawn on the vessel through conduit 20 by the degasifier vacuum pumps 36. Excess reactor coolant which is not evaporated is drawn from the vessel by discharge pumps 22, with pulse dampeners 24 employed to smooth out the pulses generated by the diaphragm discharge pumps 22. The coolant that is drawn through the discharge pumps 22 is exhausted to a holding tank 26 for return to the system or disposal. The water vapor and non-condensable gases that are separated from the coolant in the degasifier column 16 are routed through a demister 28 to remove any entrained coolant and conveyed to a vapor condenser 30 in which it is placed in heat exchange relationship with chilled water that enters and exits the vapor condenser through inlets and outlets 32 and 34. The radioactive gases and hydrogen are then drawn by vacuum pumps 36 to a degasifier separator 38. The separated coolant is then drawn off by the degasifier separator pumps 40 and discharged to the holding tank 26. The radioactive gas and hydrogen are vented from the degasifier separator 38 vapor space to the reactor plant radioactive waste gas system 42. The nitrogen purge line 44 is provided to purge any residual hydrogen and radioactive gases prior to maintenance. This traditional approach requires significant energy to operate large vacuum pumps, multiple components, e.g., degasifier columns, transfer pumps, separator vessels, interconnecting piping, valves, and instrumentation, and requires significant building space and support systems, e.g., cooling/chilled water. Thus, while these systems have a long track record, further improvement is desired that will simplify the design, reduce the energy required to operate the system, the amount of building space that is required to house the system and reduce the capital and maintenance costs of the system. These and other objects are achieved by a nuclear reactor power plant sub-system for removing radioactive gases and hydrogen gas from a reactor coolant. The sub-system includes a contactor housing a membrane that divides an interior of the contactor housing into an inlet chamber and an outlet chamber, wherein the membrane has pores that pass the radioactive and the hydrogen gases from the inlet chamber to the outlet chamber, but prevent the reactor coolant from passing through to the outlet chamber. A vacuum generator is connected to the outlet chamber for drawing a vacuum on the outlet chamber. A liquid outlet conduit is connected to an outlet nozzle on the inlet chamber for conveying a degasified portion of the reactor coolant to a desired location. Similarly, a gas outlet conduit is connected to an outlet nozzle on the outlet chamber for conveying the radioactive and hydrogen gases to a nuclear reactor power plant waste gas system. In one embodiment, a “sweep” gas system is connected to the outlet chamber for supplying a relatively small inert gas purge flow in the outlet chamber and preferably, the inert gas is nitrogen. The sweep gas, in combination with the application of a vacuum, enhances the efficiency of the membranes for dissolved gas removal, thus minimizing the required number of contactors. In still another embodiment, the contactor housing comprises a plurality of contactor housings connected in parallel. Alternately, the contactor housings may be connected in series. In still another embodiment, the contactor housing comprises a plurality of contactor housings with at least some of the plurality of contactor housings connected in parallel and some of the parallel connected contactor housings are connected in series with at least one other of the plurality of contactor housings. In still another embodiment, the contactors may be operated without a sweep gas, but may require additional contactors in series and/or parallel. This invention utilizes a known and established technology of gas membranes to remove dissolved gases from the reactor coolant. While this is a known and proven technology for some applications, it has not been previously employed to handle mildly acidic and radioactive solutions as exists in interfacing with the primary coolant of a nuclear reactor system, as evidenced by the alternative reactor degassing systems proposed in the past and described in the evaluation of prior art set forth in the Background of U.S. Pat. No. 4,647,425. In accordance with this invention, one or more alternate “contactors” which respectively house a gas membrane are aligned in series and/or parallel, as required to handle the desired flow and the degree of gas removal. Liquid containing primarily dissolved hydrogen and the radioactive gases, i.e., xenon and krypton, enters the contactors at a relatively low pressure and exits the membranes degassed to the desired level. A vacuum is applied to the gas side of the membrane to pull dissolved gases from the liquid through tiny pores in the walls of the membrane. In addition, a small inert gas sweep gas, e.g., nitrogen, flow on the vacuum side is used to enhance dissolved gas removal. This gas flow minimizes the number of required contactors. Inlet and outlet dissolved hydrogen analyzers monitor the membranes' performance. Such a system is illustrated in FIGS. 2 and 3. FIG. 2 shows two contactors 46 in parallel though it should be appreciated that one, three or four or more contactors may be employed in parallel as necessary to handle the rate of flow that is required. FIG. 3 shows the two contactors in parallel as shown in FIG. 2, with a third contactor in series with the output of the two contactors in parallel to further reduce the amount of gases that may remain within the degassed coolant stream. Referring back to FIG. 2, the letdown stream enters the system at the inlet 12 and is distributed through inlet conduit 48 to each of the inlets 50 on the contactors 46. A vacuum is applied to the gas side of the membrane at the gas outlet 52 by the vacuum pumps 54 and a small inert gas flow, preferably of nitrogen, is introduced at the gas inlets 56 from a nitrogen source 58. By “inert gas” is meant a gas that will not react with the stripped gasses, i.e., the radioactive gases or hydrogen, to form an undesirable or hazardous gas mixture when vented to the waste gas system. For example, helium gas may be used, whereas oxygen may not be used. The membrane within the contactor 46 has pores small enough to prevent the coolant from passing to the gas outlet 52, but large enough to enable the hydrogen and radioactive gases to pass through the membrane. Such contactors are available commercially, such as Liqui-Cel, available from Membrana Corporation, Charlotte, N.C. The degasified coolant then exits the contactor 46 at the outlet 60 and is conveyed by the outlet conduit 62 to a holding tank 26 where it can be returned to the reactor system or disposed of. As many contactors 46 can be arranged in parallel as necessary to handle as much volume of gas laden coolant as is needed to be recycled or disposed of. The extracted hydrogen and radioactive gases and the nitrogen sweep gas are then circulated by the vacuum pumps 54 to the plant radioactive gas waste system 42. The nitrogen source 58 also provides flow in the gas lines to purge the gas exit side of the system, for maintenance. A source of clean demineralized water 44 is provided for flushing of the liquid side of the contactors and piping prior to maintenance. FIG. 3 is identical to FIG. 2 except an additional contactor 46 is positioned in series with the parallel arrangement of contactors 46 shown in FIG. 2 and provides another stage of degasification to enhance the purity of the coolant that exits the system. Sensors are provided throughout the system to monitor the efficacy of the process. While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular embodiments disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.
	abstract	An energy absorbing and displacing structure for athletic protective equipment, such as an athletic shin-guard, is provided using a flexible web-shaped body to hold a rigid band-shaped member in place.
052395685	description	DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A gamma ray collimator assembly constructed in accordance with the invention is shown generally at 10 in FIG. 1. The collimator assembly 10 includes a housing 12, typically constructed of aluminum. Coupled to the housing 12 is a side shielding 14 which is normally constructed of lead when the collimator assembly 10 is used for collimation of gamma rays. Disposed within the housing 12 and coupled to the side shielding 14 are collimator elements 16 constructed of collimator walls 18 (best seen in FIGS. 2-4). In a preferred embodiment the collimator walls 18 are constructed of a layered material with a base material structure 20 and a thin layer 22 disposed thereon (see FIGS. 2 and 3). The radiation used in a conventional radiographic embodiment is high energy X-rays or gamma rays, and in a preferred embodiment the base material structure 20 is lead and the thin layer 22 is tin. For example, as shown in FIG. 3 in a preferred geometry the collimator walls 18 are square cross section tubing with lead being the base material structure 20 (hereinafter "lead structure 20") and tin being the thin layer 22. The tin can be readily coupled to the lead structure 20 by conventional methods such as electroplating, evaporation, ion deposition and mechanical lamination. Operation of the collimator assembly 10 is best illustrated in FIG. 2. In this example, the radiation is gamma radiation, and gamma rays 26 originate from a conventional radionuclide source, such as cobalt, thallium or technitium, which is passed through a specimen 28 (depicted schematically). As the radioactive radionuclide source decays it emits characteristic gamma rays which are emitted from or pass through the specimen 28 and form an image, such as, for example, in conventional "first pass" angiography. For example, see copending patent application Ser. No. 07/409,249 assigned to the instant assignee and is incorporated by reference herein. Other radiations can also be used in combination with the collimator assembly 10 such as, ions, neutrons, positrons, X-rays, electrons and the like. A desired gamma ray portion 30 of the gamma rays 26 travel along a substantially parallel line 32 or within a very narrow angular range within which the gamma ray portion 30 does not strike the collimator assembly 10. The desired gamma ray portion 30 thus passes undisturbed through the collimator assembly 10. This desired gamma ray portion 30 is sensed by a conventional detector 34, such as, a gamma ray counter of a conventional Anger camera or a sensor of a first pass cardiac inspection system, such as the angiographic system of Scinticor Incorporated of Milwaukee, Wis. In addition to the desired gamma ray portion 32, having a substantially unchanged primary energy E.sub.0 after emission from the radiation source, there is a substantial fraction of divergent gamma rays 31 from the specimen 28. These divergent gamma rays 31 interact with the collimator walls 18 and result in diminished resolution of spatial features of the specimen 28. The desirability of removing such divergent gamma rays 31 is well known. For example, in U.S. Pat. No. 4,096,389 (which is incorporated by reference herein) the benefits of effective collimation, generally, are described for X-ray and gamma ray radiographic imaging technology. Such advantages also are apparent for other conventional radiographic systems, such as in emission tomography systems and Anger camera geometries (see, for example, U.S. Pat. Nos. 4,295,047; 4,682,033; 4,852,142; 4,672,648; and 4,277,684, which are incorporated by reference herein). The divergent gamma rays 31 interact with the collimator walls 18 and the divergent gamma rays 31 lose energy, creating inelastic scattered radiation 36 having energies less than E.sub.0 of the initial gamma rays 26. In order to achieve optimum resolution, the divergent gamma rays 31 (and the inelastic scattered byproduct radiation) should be substantially removed by the collimator assembly 10. Removal of the inelastic scattered radiation 36 would allow sensing and analysis of only the desired gamma ray portion 30 which is substantially parallel to line 32 in FIG. 2 and includes undisturbed gamma rays 30 from the specimen 28. This desired gamma ray Portion 30 is then sensed by detector 34. This enables achieving the desired level of resolution for the features of the specimen 28. As mentioned hereinbefore, the divergent gamma rays 31 before interaction with the collimator walls 18 have an energy of E.sub.0, and after wall interaction the inelastic scattered radiation 36 includes a range of electromagnetic wave energies, from E.sub.0 at a maximum to lesser values. In the case of an inelastic interaction, the divergent gamma rays 31 interact with the lead structure 20 of the collimator assembly 10. When the gamma rays 31 (such as, cobalt radionuclide gamma rays having an energy of roughly 140 KeV) enter the lead structure 20, energy can be lost by a variety of processes. For example, energy can be lost by excitation of electrons from the ground state in each of the lead atoms. These excited electrons return to their ground state energy level and simultaneously emit a characteristic X-ray, such as Pb K-alpha radiation having an energy of about 74 KeV. Numerous other electron excitations and decays to ground state occur, giving rise to lower energy X-rays and other electromagnetic wave species which are preferentially absorbed within the lead structure 20. These events normally occur without reemitting any X-rays into the collimator free space outside the lead structure 20, and thus the lower energy radiation is not normally detected by the detector 34. Therefore, as stated above, when the divergent gamma rays 31 enter the lead structure 20, a 74 KeV X-ray can escape into free space as a consequence of inelastic scattering of the 140 KeV cobalt gamma ray. This emitted 74 KeV inelastic scattered X-ray 36 travels along line 42 (see FIG. 2) and is sensed by the detector 34. Conventional energy discriminators in an electronic detection system 37 (shown schematically), which is coupled to the detector 34, can remove the unwanted signal arising from the inelastic scattered X-ray 36. However, such a sensed event can cause substantial loss of resolution which is detrimental to spatial (or angular) resolution. This loss of resolution can result because the event is still counted by the counter 34 and prevents detection of the desired undeviated gamma ray portion 32. Conventional counter electronics in the detection system 37 can only count at a given finite rate, such as, for example, 100,000 to 1,000,000 counts per second, and detection of unwanted energetic photons (or particles) prevents accumulating a desired event. The need to maximize useful signal (coupled with the limits on the ability of the electronics to count all incoming events) makes it imperative to remove the emitted, or inelastically scattered, X-rays 36 in order to use the full capacity of the counter 34 to sense the desired gamma ray portion 30. In FIGS. 2 and 3 is shown the layered wall structure of the collimator assembly 10. This layered wall structure enables detection of substantially only the gamma rays 30 and by removal of the unwanted inelastic scattered X-rays 36 so such a component is not sensed by the detector 34. As shown in the preferred embodiment, the thin layer 22 is tin but can be any material which exhibits a large absorption coefficient for the energetic inelastic scattered X-rays 36 emitted from the underlying lead structure 20. The tin layer 22 can be quite thin (for example, about 1/4 mm) and still be quite effective in absorbing the inelastic scattered lead K-alpha X-rays 36. As can be understood from conventional X-ray optics (and other appropriate spectroscopic sciences, such as ion optics) the only portion of energetic photons which might be sensed by the detector 34 is emitted primarily at relatively small angles with respect to the line 32. The geometry of the collimator assembly 10, including the length "l" in FIG. 2 and the other dimensions (see FIG. 3) result in the reemitted inelastic scatterd X-rays 36 traveling over a substantial path length within the tin layer 22. As a consequence of the large path length travelled at such small angles relative to direction 32, and the well known exponential absorption attenuation, the tin layer 22 is very effective in removing the unwanted inelastic scattered X-rays 36. The ratio of transmitted intensity to initial intensity is exp (-.mu..multidot.t), where .mu. is the well known linear absorption coefficient of tin (about 28.1 cm.sup.-1 at 75 Kev), and "t" is the path length travelled by the inelastic scattered X-rays 36 in the tin layer. The effect of the collimator assembly 10 on reducing the X-rays 36 is demonstrated dramatically by comparing FIGS. 5A and 5B. FIG. 5A shows the radiation sensed by the detector 34 in a Scinticor angiographic system for a collimator system having only a lead base structure. As can be seen in FIG. 5A, there are two prominent peaks sensed, one peak at about 75 KeV associated with the lead K-alpha inelastically scattered X-rays 36 and the second cobalt gamma ray peak at about 140 KeV. The nearly equal prominence of the intensity of the two peaks points out the significance of removing the inelastic scattered X-rays 36. In FIG. 5B is shown the energy spectrum detected employing the collimator assembly 10 with substantially identical collimator dimensions. As demonstrated by the data of FIG. 5, the collimator assembly 10 is highly effective in the removal of the lead K-alpha inelastic scattered X-rays 36, thus enabling the detector 34 to sense only the desired gamma ray portion 30. Consequently, the efficiency of detection for a given radionuclide source intensity in the specimen 28 can be substantially enhanced. As determined by actual experiment in Scinticor angiographic systems this is about 50 percent for the illustrated embodiment wherein the number of 140 KeV events detected increases, for example, from about 400,000 to 600,000 counts Per second. Such an improvement in efficiency also results in enhanced signal which manifests itself as improved image resolution of the specimen cardiac system. For example, as shown by the angiographic image data of FIGS. (6i-6viii), a cardiologist is now able to resolve critical features previously unresolvable. The use of the collimator assembly 10 has, however, substantially improved resolution such that high quality first pass angiography can now be performed routinely. For example, as shown by the angiographic image data of FIGS. 6-14, a cardiologist is now able to resolve critical features previously unresolvable. The use of the collimator assembly 10 has, therefore, substantially improved resolution such that high quality first pass angiography can now be performed routinely. A shown in FIGS. 7-14, the resulting images are of high quality, enabling a cardiologist to more effectively perform diagnoses previously made without the benefit of such detailed medical information. In regard to the angiographic image data, FIG. 7 shows an example time lapse photograph for each block of a matrix of time lapse photographs of a patient's cardiac system in an RNA (radionuclide angiographic) study on a SIM400. This figure illustrates passage of a bolus through the central circulation during a first pass RNA study. FIG. 6 shows the explanation key for the matrix of time lapse photographs of FIGS. 7-14, and the numbers in the lower right hand corner of FIG. 6 are elapsed time in seconds. These images are compressed by a factor of thirty times the original framing rate. The abbreviation keys in FIG. 6 are referenced as follows: Image Descriptions (Read from left to right and top to bottom.) Key B-Bolus PA0 RA-Right Atrium PA0 PA-Pulmonary Artery PA0 LL-Left Lung PA0 L-Lungs; includes RL and LL PA0 LA-Left Atrium PA0 LV-Left Ventricle PA0 AO-Proximal Aorta PA0 AT-Aortic Outflow Track PA0 DA-Descending Aorta PA0 MY-Myocardium PA0 LH-Left Heart; includes LA, LV, AO, AT, DA PA0 RC-Recirculation; includes LH and RH PA0 SVC-Superior Vena Cava PA0 RV-Right Ventricle PA0 RH-Right Heart includes RA, RV, PA PA0 RL-Right Lung PA0 A.sub.1 =area of lead square (edge "b" squared) PA0 A.sub.2 =area of tin square (edge "a" squared) PA0 l=longitudinal length of collimator passageway (see FIG. 2) PA0 M=center to center spacing (see FIG. 2) FIG. 8A is an RNA study performed Sep. 22, 1989 on patient Beau using the Conventional Lead Collimator on SIM400. FIG. 8B is another RNA study performed on patient Beau. The study was performed Sep. 18, 1990 using a research model of the Tin/Lead Collimator on SIM400. The conclusions reached are that RH, L, and LH phases are clearly better imaged with the Tin/Lead Collimator in FIG. 8B than FIG. 8A and that the LV is especially better defined in FIG. 8B. Note that the study parameters were essentially identical in both FIGS. 8A and 8B studies; these include bolus technique, dose, patient positioning, image processing, and all hardware except the collimators. In FIG. 9A is shown data for patient Cul. An RNA study was performed on Jun. 9, 1989 using the Conventional Lead Collimator on SIM400. Another RNA study was performed on patient Cul on Sep. 5, 1990 using a research model of the Tin/Lead Collimator on SIM400 as illustrated in FIG. 9B. The study concluded (a) that the RH and LH chambers are more clearly delineated in FIG. 9B; (b) the LV, RV and PA are better resolved in FIG. 9B than 9A; and (c) the valve planes are not delineated in FIG 9A, especially the pulmonary valve between RV and PA and the Aortic valve between LV and 40 which are clearly visualized in FIG 9B. Note the study parameters and protocols are essentially identical in FIGS. 9A and 9B except for the collimators as indicated. FIG. 10A illustrates the results of an RNA study performed on patient Rose on May 5, 1989 using the Conventional Lead Collimator on SIM400. Another RNA study was performed on patient Rose on Sep. 10, 1990 using a research model of the Tin/Lead Collimator on SIM400. The study concluded that (a) the LV in FIG. 10B is well visualized from the Aortic valve plane to the apex compared to FIG. 10A which merges the LV with the AO; (b) the LL in FIG. 10 is well separated from the LV chamber strongly suggesting that FIG. 10B has much reduced anatomic background and Compton scatter background compared to FIG. 10A; and (c) the AO valve plane is clearly visualized in FIG. 10B but burnt out by saturated counts in the AT in FIG. 10A. Note the study parameters and protocols were essentially identical in both RNA studies except for the collimators as indicated. The Conventional Lead Collimator was used in an RNA study performed Jun. 21, 1989 on patient Badu illustrated in FIG. 11A. In FIG. 11B is shown data for another study on patient Badu. This figure illustrates the (--NORTH--)y study performed Aug. 22, 1990 using a research model of the Tin/Lead Collimator on SIM400. The conclusions of the study are as follows: (a) FIG. 11B clearly shows improved resolution and contrast compared to FIG. 11A; (b) the LV is better resolved in FIG. 11B; and (c) the lungs are well separated from the Right and Left Ventricular chambers in FIG. 11B compared to FIG. 11A. This leads to a 50% reduction in lung background over the LV in FIG. 11B compared to FIG. 11A. The study parameters and protocols were essentially identical in both studies of FIGS. 11A and 11B except for the collimators as indicated. An RNA study was performed on patient Quag on Jun. 26, 1989 using the Conventional Lead Collimator on a conventional System 77 as is illustrated in FIG. 12A. FIG. 12B shows another RNA study of patient Quag performed Aug. 17, 1990 using a research model of the Tin/Lead Collimator on SIM400. The study concluded that the RV, LV and valve planes between RV and PA and between LV and AO are all better visualized in FIG 12B compared to FIG. 12A and that the DA and onset of myocardial blush can be seen in FIG. 12B but not in FIG. 12A. This is an important comparison because FIG. 12A was performed on System 77 which has been the gold standard of RNA studies since 1972 and, until the research on SIM400 with the development of the Tin/Lead collimator, the System 77 represented the state of the art in First Pass collimators. The study parameters and protocols were essentially identical in both studies (FIGS. 12A and 12B). Both received the same image processing treatment on a SIM400. FIG. 13A shows data from a study performed on patient Chak in which a high spatial resolution dead collimator was used. Such collimators are not normally used in first pass studies because of its low efficiency. However, this study shows that spatial resolution alone cannot bring a first pass study to the quality achieved with the Tin/Lead collimator of FIG. 13C. The reason for this is shown in the Compton Scatter Image obtained in FIG. 13B. The data of FIG. 13B were obtained by performing a simultaneous dual energy study to allow a comparison of imaging a first pass RNA study with photopeak events and Compton Scatter and Pb X-ray events. This panel clearly shows the poor image quality that results from scatter and Pb X-ray events. The purpose of the Tin/Lead collimator is to reduce this imaging component. In FIG. 13C is shown an image produced in an RNA study performed on patient Chak on Aug. 17, 1990 using a Tin/Lead collimator. This study is superior to the photopeak study of FIG. 13A even when it is performed with the most highly optimized conventional lead collimator and high spatial resolution. It can be seen that the pure scatter/Pb X-ray image illustrated in this figure bears a tell-tale resemblance to the images shown using the conventional lead collimator. FIG. 14A is an image resulting from an RNA study performed on patient Mel on Jul. 31, 1989 using the conventional lead collimator on SIM400. FIG. 14B shows an image which was produced in a slow bolus study also performed on patient Mel on Sep. 4, 1990 using a research model of the Tin/Lead collimator on SIM400. The study concluded that FIGS. 14A and 14B are somewhat comparable in quality. Preferably, the tin layer 22 does not have too high an atomic number, or the thin layer 22 can itself reemit a high energy X-ray which could be transmitted through the thin layer 22 and be sensed by the detector 34. Knowing the composition of the base structure 20, one can apply conventional radiation absorption knowledge and methods to determine the appropriate materials and their layer thicknesses necessary to absorb a substantial fraction of any inelastic scattered radiation, particularly emitted K alpha and L alpha X-rays from the base collimator structure 20. This basic concept of layered wall collimators can be applied to any radiation collimator, such as for X-rays, ions, infrared laser light, positrons, electrons, neutrons and microwave or other photon energies. Associated with each of these radiations is a known, developed knowledge of absorption and inelastic scattering events. In those instances in which inelastic scattered radiation can be produced, such unwanted data can be preferentially removed in the manner described. The efficiency of the gamma ray collimator assembly 10 can be assessed with reasonable accuracy for the square cross section collimator geometry illustrated in FIG. 3. The efficiency is expressed in terms of the spatial dimensions: EQU E=A.sub.1 A.sub.2 /4.pi.l.sup.2 M.sup.2 Thus, one can select a desired efficiency by adjusting the various geometries of the collimator assembly 10. In another aspect of the invention the collimator assembly 10 can be constructed of any desired height and longitudinal length l, along the collimator assembly 10. The user can then assemble a final collimator assembly 10 of any desired length of longitudinal passageway by stacking two or more different height collimator assemblies. While preferred embodiments of the invention have been shown and described, it will be clear to those skilled in the art that various changes and modifications can be made without departing from the invention in its broader aspects as set forth in the claims provided hereinafter.
	claims	1. A radiation computed tomographic imaging apparatus comprising:a radiation source for emitting radiation while rotating around a predefined axis of rotation, wherein said radiation source has an X-ray focal spot;a radiation detector for detecting said radiation passing through a subject around said axis of rotation, said radiation detector having a plurality of radiation detector elements for detecting said radiation, extending in a two-dimensional manner in first and second arrangement directions, said first arrangement direction being contained in a plane of rotation of said radiation source, said second arrangement direction being orthogonal to said first arrangement direction and aligned along said axis of rotation; anda reconstructing device for arithmetically reconstructing tomographic image data for a tomographic image of said subject based on projection data of said subject obtained from said radiation detected by said radiation detector, wherein said radiation detector comprises collimators for confining an angle at which said radiation impinges upon said radiation detector elements, said collimators being provided at borders between said radiation detector elements adjoining in said second arrangement direction, and wherein a first one of said collimators has a first height determined based on a drift of said X-ray focal spot. 2. The radiation computed tomographic imaging apparatus of claim 1, wherein:said plurality of radiation detector elements are arranged in said first arrangement direction to form a curve along the direction of rotation of said radiation source, and flatly arranged in said second arrangement direction. 3. The radiation computed tomographic imaging apparatus of claim 1, wherein:said radiation is emitted from said focal spot of said radiation source;said radiation source and said radiation detector are disposed symmetrically with respect to a line connecting said focal spot and a midpoint in said second arrangement direction; andsaid radiation computed tomographic imaging apparatus further comprises a moving device for rotating said radiation source and said radiation detector around said axis of rotation while maintaining their positional relationship relative to each other. 4. The radiation computed tomographic imaging apparatus of claim 3, wherein:said collimators are provided at positions other than said midpoint in said second arrangement direction. 5. The radiation computed tomographic imaging apparatus of claim 4, wherein:said collimators are provided at regular intervals in said second arrangement direction. 6. The radiation computed tomographic imaging apparatus of claim 1, wherein:the first height is determined based on efficiency of radiation usage by at least one of said radiation detector elements. 7. The radiation computed tomographic imaging apparatus of claim 6, wherein:the first height is smaller than a second height of a second one of said collimators, and wherein said first collimator lying farther from said midpoint in said second arrangement direction than said second collimator. 8. The radiation computed tomographic imaging apparatus of claim 1, wherein:said radiation detector further comprises said collimators at borders between said radiation detector elements adjoining in said first arrangement direction as well. 9. The radiation computed tomographic imaging apparatus of claim 1, wherein the first height is determined based on a threshold exceeded by an efficiency of X-ray usage of at least one of said radiation detector elements. 10. The radiation computed tomographic imaging apparatus of claim 1, wherein said collimators are located at a position other than a center of said radiation detector. 11. A radiation computed tomographic imaging apparatus comprising:a radiation source for emitting radiation while rotating around a predefined axis of rotation;a radiation detector for detecting said radiation passing through a subject around said axis of rotation, said radiation detector having a plurality of radiation detector elements for detecting said radiation, extending in a two-dimensional manner in first and second arrangement directions, said first arrangement direction being contained in a plane of rotation of said radiation source, said second arrangement direction being orthogonal to said first arrangement direction and aligned along said axis of rotation; anda reconstructing device for arithmetically reconstructing tomographic image data for a tomographic image of said subject based on projection data of said subject obtained from said radiation detected by said radiation detector, wherein said radiation detector comprises collimators for confining an angle at which said radiation impinges upon said radiation detector elements, said collimators being provided at borders between said radiation detector elements adjoining in said second arrangement direction, and wherein said reconstructing device corrects a difference in radiation detection sensitivity among said radiation detector elements due to a shadow of said collimators created in emission of a beam of said radiation. 12. The radiation computed tomographic imaging apparatus of claim 11, wherein:said reconstructing device makes said correction based on a value of a sensitivity correction vector selected based on a ratio between a detected value by a first one of reference channels in which said radiation detection sensitivity varies and a detected value by a second one of reference channels in which said radiation detection sensitivity is invariant, said reference channels being those among said plurality of radiation detector elements that always detect said radiation not passing through said subject. 13. The radiation computed tomographic imaging apparatus of claim 12, wherein:elements in said sensitivity correction vector have individual values respectively corresponding to said radiation detector elements in said first arrangement direction. 14. A radiation detector for use in a radiation computed tomographic imaging apparatus for generating tomographic image data for a tomographic image of a subject based on projection data of said subject obtained from radiation emitted from a radiation source rotating around a predefined axis of rotation and passing through said subject, wherein said radiation detector comprises:a plurality of radiation detector elements for detecting said radiation for acquiring said projection data, extending in a two-dimensional manner in first and second arrangement directions, said first arrangement direction being contained in a plane of rotation of said radiation source, said second arrangement direction being orthogonal to said first arrangement direction and aligned along said axis of rotation; andcollimators for confining an angle at which said radiation impinges upon said radiation detector elements, provided at borders between said radiation detector elements adjoining in said second arrangement direction, wherein a first one of said collimators has a first height determined based on a drift of an X-ray focal spot of the radiation source. 15. The radiation detector of claim 14, wherein:said plurality of radiation detector elements are arranged in said first arrangement direction to form a curve along the direction of rotation of said radiation source, and flatly arranged in said second arrangement direction. 16. The radiation detector of claim 14, wherein:said radiation detector is configured to be symmetric with respect to a line connecting the focal spot of said radiation source and a midpoint in said second arrangement direction; andsaid collimators are provided at positions other than said midpoint in said second arrangement direction. 17. The radiation detector of claim 16, wherein:said collimators are provided at regular intervals in said second arrangement direction. 18. The radiation detector of claim 14, wherein:the first height is determined based on efficiency of radiation usage by at least one of said radiation detector elements. 19. The radiation detector of claim 18, wherein:the first height is smaller than a second height of a second one of said collimators, and wherein said first collimator lying farther from said midpoint in said second arrangement direction than said second collimator. 20. The radiation detector of claim 14, further comprising:said collimators at borders between said radiation detector elements adjoining in said first arrangement direction as well.

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