Development of High Resolution X-Ray Crystal Spectrometry for HED Plasmas

High resolution ($\lambda$/$\delta\lambda$ $\sim$10,000) 1D spatially resolved x-ray spectroscopy using a spherically bent crystal and a 2D hybrid pixel array detector is used world wide for Doppler measurements of ion-temperature and plasma flow-velocity profiles in magnetic confinement fusion plasmas. Meter sized plasmas are diagnosed with cm spatial resolution and 10 ms time resolution. This concept can also be used as a diagnostic of small sources, such as high energy density plasmas (HEDP) and targets on x-ray light source beam lines, with spatial resolution of microns, as demonstrated by laboratory experiments using a 250-micron 55Fe source, and by ray-tracing calculations. Throughput calculations agree with measurements, and predict detector counts in the range 10-8 -- 10-6 times source x rays, depending on crystal reflectivity and spectrometer geometry. Results of the lab demonstrations, application of the technique to HEDP facilities, and predictions of performance on these facilities will be presented.