text: 40,136,1281486695515529216,994520594489204737,Jack Hare,"New arXiv paper, ""An Imaging Refractometer for Density Fluctuation Measurements in High Energy Density Plasmas"" <LINK>. This new diagnostic analyses a laser beam passing through #turbulent #Plasma, recording ray locations and ray deflections in orthogonal axes. <LINK> The idea is that the spectrum of ray deflections relates to the spectrum of density fluctuations within the turbulent plasma. These fluctuations were studied with digital Fourier transforms of shadowgraphy and schlieren images, but our new technique resolves much smaller scales. <LINK> We compare our diagnostic to existing methods using ray tracing techniques, and present data from an experiment which shows the exquisite detail we can capture. Next up: going beyond the power spectrum and looking for signatures of intermittency in magnetohydrodynamic turbulence. <LINK> Thanks to everyone who has helped with this paper, it's been a long journey. The data is from 2016, so it's taken a pandemic to finally analyse it. Along the way we've developed a really nice ray-tracing/ray-transfer-matrix code which we can use for all our optical diagnostics.",https://arxiv.org/abs/2007.04682,"We report on a recently developed laser-probing diagnostic which allows direct measurements of ray-deflection angles in one axis, whilst retaining imaging capabilities in the other axis. This allows us to measure the spectrum of angular deflections from a laser beam which passes though a turbulent high-energy-density plasma. This spectrum contains information about the density fluctuations within the plasma, which deflect the probing laser over a range of angles. %The principle of this diagnostic is described, along with our specific experimental realisation. We create synthetic diagnostics using ray-tracing to compare this new diagnostic with standard shadowgraphy and schlieren imaging approaches, which demonstrates the enhanced sensitivity of this new diagnostic over standard techniques. We present experimental data from turbulence behind a reverse shock in a plasma and demonstrate that this technique can measure angular deflections between 0.06 and 34 mrad, corresponding to a dynamic range of over 500. ","An Imaging Refractometer for Density Fluctuation Measurements in High