Electrode layout simulation for JAEA 10A multi-cusp source discharge

The JAEA 10A multi-cusp source discharge is simulated by the self-developed full 3D PIC/MCC software. The influence of the electrode layout on H^- volume generation efficiency was analyzed. The simulation shows that with a certain discharging power, the crosswise drifting from high energy electrons will weaken relatively when the number of electrodes decreases, then the uniform H^- beam will be obtained. However, the lower electrodes lead to a lower generation efficiency of the H^- volume. When the electrodes are close to magnetic filtering region, the crosswise drifting will be strengthen relatively and the H^- volume generation efficiency is quite low. With changing the number of electrodes, the high H^- volume generation efficiency and the good space uniformity couldn't be obtained together. The electrodes far away from magnetic filtering region are the best choice. (authors)