Belchenko Yu, Ivanov A, Konstantinov S, Sanin A, Sotnikov O
Budker Institute of Nuclear Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia.
Rev Sci Instrum. 2016 Feb;87(2):02B133. doi: 10.1063/1.4935242.
Experiments on hydrogen negative ions production in the large radio-frequency negative ion source with cesium seed are described. The system of directed cesium deposition to the plasma grid periphery was used. The small cesium seed (∼0.5 G) provides an enhanced H(-) production during a 2 month long experimental cycle. The gradual increase of negative ion yield during the long-term source runs was observed after cesium addition to the source. The degraded H(-) production was recorded after air filling to the source or after the cesium washing away from the driver and plasma chamber walls. The following source conditioning by beam shots produces the gradual recovery of H(-) yield to the high value. The effect of H(-) yield recovery after cesium coverage passivation by air fill was studied. The concept of cesium coverage replenishment and of H(-) yield recovery due to sputtering of cesium from the deteriorated layers is discussed.
描述了在带有铯种子的大型射频负离子源中产生氢负离子的实验。使用了将铯定向沉积到等离子体栅极周边的系统。少量铯种子（约0.5克）在为期2个月的实验周期内提高了H(-)的产生量。在向源中添加铯后，观察到在长期运行过程中负离子产率逐渐增加。在向源中充入空气后或铯从驱动器和等离子体腔室壁上被冲洗掉后，记录到H(-)产生量下降。随后通过束流轰击进行源调节会使H(-)产率逐渐恢复到高值。研究了在通过充气使铯覆盖钝化后H(-)产率恢复的效果。讨论了铯覆盖补充以及由于铯从劣化层溅射而导致H(-)产率恢复的概念。
