Development of steady state microwave ion source for high flux ion beam irradiation to first wall materials

A steady-state microwave ion source for high flux ion beam irradiation to first wall materials has been developed. It consists of a plasma source chamber and a plasma diffusion chamber with multi-cusp permanent magnets. In this study, the characteristics of ion saturation current and the beam power density were studied. It was found that gas pressure and gas inlet position affected plasma characteristics. The beam power density of 48 W/cm2 was obtained for acceleration voltage of 3.0 kV. In this case, hydrogen flux is 1021 H/m2s, if all of ions are H+. This flux is an order of magnitude higher than conventional mass-separated ion beam devices (<1020 H/m2s). (author)