Deposits removal and hydrogen release on co-deposited films exposed to O-ICR and O-GDC plasmas in HT-7

A few new results of oxidation wall conditionings for deposits removal and hydrogen release were directly obtained on exposure of co-deposited films to O-ICR or O-GDC plasmas in HT-7. After the O-ICR or O-GDC treatments, the deposits were partially removed and deuterium retention was reduced. D-2 release from samples was reduced by a factor of 2-3, and the ratio of D/C decreased whereas that of O/C increased. The removal rates of C in various oxidation wall conditionings were about 10(18)-10(19) Cm-2 min(-1), which approached the estimated carbon deposited rates, of about 5.2 x 10(18)Cm(-2) min(-1), on the tested samples. The He/O-ICR was more effective on the deposits removal and hydrogen ( deuterium) release than O-GDC. And O-ICR was more effective on the surface facing main plasma than on that facing SOL plasma, whereas O-GDC possibly has uniform effectivity on both tested surfaces.