Krypton Spectroscopy Diagnosis of High-Temperature Implosions

High-temperature implosions are planned for the OMEGA Upgrade experimental program. By using relatively thin shell targets, temperatures much higher than 1 keV at modest compressed densities (1 to 5 g/cm3) are predicted. The goal of this work is to demonstrate that by adding a small admixture of krypton gas (-0.01 atm) to the fuel, the temperature can be conveniently diagnosed through the spectrum of helium-like (K,'~') and hydrogen-like ( ~ r ' ~ ~ ) lines. By increasing the fill pressure, resonant Kr lines can become opaque, through selfabsorption, and their relative intensities can be used to diagnose shell-fuel mixing.