Detailed observation and analysis of radiation from high-density laser-imploded targets

High-energy CO₂-laser radiation has been used to implode gas-filled spherical targets to very high densities (10²³<nₑ<10²⁴ cm^-3) and temperatures ({~}800 eV). The imploded gas was composed primarily of DT with a small amount of argon seed. The detailed observation of radiation from the argon was a primary diagnostic of the imploded-plasma conditions. An extensive analysis of the emitted argon spectrum provides a rich source of information on plasma parameters. In most cases one could not assume local-thermodynamic-equilibrium conditions. A very detailed collisional-radiative model was constructed in order to analyze the spectrum. In view of the complexity of the calculations that had to be performed and the care needed in data acquisition and processing, the agreement between theory and experiment was very good.