Calibrated ’’four-color’’ x-ray microscope for laser plasma diagnostics

Abstract

Four quartz, orthogonal, cylindrical mirror pairs, two of which are coated with nickel, image the x-ray emission from laser fusion targets on hard film with a magnification of 3. K-edge filters used in conjunction with the mirror pairs permit us to take simultaneous pictures in four energy bands between 0.7 and 3.5 keV. We have measured microscope resolution, mirror reflection efficiency, and film sensitivity and used them to deduce the absolute emissivity and spectral characteristics of various laser fusion targets. This instrument is now used routinely for studying laser-generated plasmas at Lawrence Livermore Laboratory.