25 - 100-keV X-Ray Diagnostics for the 200-TW Trident Laser

Abstract

The sub-ps Trident laser is upgraded to deliver >100 J on target. We are prepared to measure conversion efficiencies of 200-TW laser light to K-shell emission. X-ray diagnostics include a simple, inexpensive Laue X-ray spectrograph and a set of Ross filter pairs. The sensitivity of Si p-i-n diodes is adequate to record X-ray emission up to 100 keV. With carefully matched Ross filter pairs, the diodes permit estimation of the signal between the filter edges of two channels through subtraction of signals. Estimates suggest that the signal-to-noise ratio of the K-shell signal to X-ray continuum and leakage from filter mismatch is adequate to determine the conversion efficiency. These instruments will be employed to optimize the efficiency of X-ray backlighters in this energy range.