X-ray Doppler Velocimetry For Diagnosis of Fluid Motion in ICF Implosions

We are developing a novel diagnostic for measurement of bulk fluid motion in materials, that is particularly applicable to very hot, x-ray emitting plasmas in the High Energy Density Physics (HEDP) regime. The X-ray Doppler Velocimetry (XDV) technique relies on monochromatic imaging in multiple x-ray energy bands near the center of an x-ray emission line in a plasma, and utilizes bent imaging crystals. Higher energy bands are preferentially sensitive to plasma moving towards the viewer, while lower energy bands are preferentially sensitive to plasma moving away from the viewer. Combining multiple images in different energy bands allows for a reconstruction of the fluid velocity field integrated along the line of sight. We review the technique, and we discuss progress towards benchmarking the technique with proof-of-principle HEDP experiments.