Simulation of surface response at the first wall of a fusion ignition experiment

Future fusion ignition experiments such as IGNITEX are likely to use low-Z materials for plasma-facing surfaces. Consequently, there is a need for calculating the surface response of low-Z materials exposed to ignited DT plasmas. The PLASUR code has been developed to address this type of problem. The interactions modeled in PLASUR are sputtering, backscattering, implantation, and thermalized release. These interactions are the basic plasma-wall phenomena in fusion experiments. The local mixing model is used to model thermalized hydrogen release from a wall surface. When hydrogen ions are implanted within a non-porous low-Z surface at ambient temperature, they become trapped at the location where thermalization takes place. They remain trapped provided the concentration of hydrogen remains below the saturation level. Upon reaching the saturation region. The release of hydrogen from a surface which becomes saturated, is modeled rather well by the local mixing model employed here