Numerical Simulation of the EEDF and the Neutral Transport in the DC Arc-Discharge Hydrogen Negative Ion Source for Medical Use

A Multi-cusp DC arc-discharge hydrogen negative ion (H-) source has been developed for proton cyclotron applications. The purpose of this study is to understand the dependency of the H- surface production on the operation parameters and optimize the H- surface production in the source. In this paper, spatial distribution of H atom production due to the H-2 dissociation and H atom flux onto the plasma grid (PG), both of which play a key role for the H- surface production, have been calculated by the KEIO-MARC code and the neutral (H-2, H) transport code. These simulation results provide useful information for optimization of the H- surface production in the source.