关键词: 射频负离子源, 表面产生, 铯注入, 温度控制

Abstract: In order to enhance the transport of cesium vapor from the cesium nozzle to the plasma electrode in a radio-frequency driven negative hydrogen ion source, the cesium feeding process on a radio-frequency driven negative hydrogen ion source was experimentally investigated. In the experiment, elemental cesium was applied as the source of cesium vapor, and cesium gun was fed into the negative hydrogen ion source. A spectrometer was used to monitor the intensity of the cesium emission spectrum (852 nm) near the plasma electrode to assess the cesium vapor content. In the experiment, the emission spectrum intensities of cesium near the plasma electrode are compared for the diffusion chamber of the negative ion source under good cooling and the active heating conditions. The results show that the active heating of the diffusion chamber of the negative ion source can greatly enhance the transport of cesium. By comparing the effect of two different types of cesium nozzles (straight and side nozzles), it is found that the straight nozzles are difficult to produce uniformly distributed cesium deposition on the plasma electrode, but the combination of the side nozzles and the active heating of the diffusion chamber can make the cesium deposition on the surface of the plasma electrode more uniform.

Key words: Radio frequency negative ion source, Surface generation, Cesium injection, Temperature control