Energy transport benchmark for nonhomogeneous target plasmas

Summary form only given, as follows. Plasma stream target interactions at the MW/cm/sup 2/ power density level of the impacting source result in immediate evaporation of target material and in early formation of a protective plasma shield in front of the target. The target plasma for low Z materials is a two zone plasma with a hot low dense plasma corona and a cold rather dense plasma layer towards the target. The plasma corona in which the plasma stream is stopped converts the incoming energy with an efficiency of up to 50 % into soft X-ray (SXR) radiation. The energy transport in such a plasma shield has to deal with the transfer of intense SXR radiation through cold and dense plasma layers and has to take into account reabsorption of the SXR line radiation in the cold plasma. To describe such processes a self-consistent approach in which the interaction of the radiation field with the plasma locally is taken into account is required. A comparison of results from opacity and self-consistent approach clearly demonstrates an increase in energy transfer through the plasma shield in case of the self-consistent approach of a factor of 4 for a power density of the impinging beam of 10 MW/cm/sup 2/. To check the adequacy of the self-consistent approach energy transfer benchmark calculations were performed at CEA, FZK, LLNL and Lykov for nonhomogeneous beryllium and carbon plasma shields. The paper describes the benchmark and the models used in the different calculations and gives a discussion of the different results obtained.