X-ray spectroscopy of plasmas created by the Nike KrF laser

The x-ray emission from plasmas created by the Naval Research Laboratory Nike KrF laser was characterized using spectroscopic instruments. The targets were thin foils of aluminum and titanium and were irradiated by laser energies in the range 100-1500 J. Using a spherical-crystal imaging spectrometer operating in the 1-2 keV x-ray region, the density, temperature, and opacity of aluminum plasmas were determined with a spatial resolution of 10 mu m in the direction perpendicular to the target surface. The spectral line ratios indicated that the aluminum plasmas were relatively dense, cool, and optically thick near the target surface.