Effect of cesium on H− production in a field free region of a volume source

The H− density and temperature in a cesium injected hydrogen discharge of the driver region of tandem H− source were investigated by use of photodetachment technique. The amount of cesium in the ion source was monitored by spectroscopic measurement. The plasma space potential, Vs, obtained from the probe I–V characteristics has increased by Cs injection. However no clear changes in ne, n−, Te, T+, and T− are observed.