Effect of energy relaxation of H⁰ atoms at the wall on the production profile of H^- ions in large negative ion sources

Production and transport processes of the H0 atoms are numerically simulated using a three-dimensional Monte Carlo transport code. The code is applied to the large JAEA 10 ampere negative ion source under a Cs-seeded condition to obtain a spatial distribution of surface-produced H- ions. In this analysis, we focus on the effect of the energy relaxation of the H0 atoms at the wall on the H- ion production from the H0 atoms. The result indicates that, by considering the energy relaxation of the H0 atoms at the wall, the production profile of the surface-produced H- ion is well reflected in the production profile of the H0 atom production.