Time And Space Resolved X-Ray Spectra Of Imploding Laser Fusion Targets

X-ray crystal spectroscopy of laser produced plasmas has long been considered an important diagnostic of plasma density and temperature.(1) Absorption spectroscopy of the dense transient plasmas existing in imploding laser fusion targets has the potential of being an important avenue of fuel and shell density and temperature diagnosis.(2,3) Meaningful data, however, will require sufficient space and/or time resolution to pinpoint the region of the plasma being diagnosed. In this paper we review recent progress made in this area in studying spherical fusion targets imploded by the 24 beam OMEGA laser system at LLE.(4) Space resolved spectra have been obtained with a multi-frame imaging planar crystal i)ectrometer,(5) and time-resolved data with the SPEAXS curved crystal streak spectrograph.(6'7) The evolution of the intensity of the spectral features as a function of space for different types of targets has been investigated in order to make estimates of the density and temperature of the shell during the final stages of compression of the imploding fusion target. Comparisons of this technique with other diagnostic approaches are also made.