Development of negative hydrogen ion sources for fusion: Experiments and modelling
- 作者：U. Fantz ; fantz@ipp.mpg.de ; P. Franzen ; D. Wü ; nderlich
- 关键词：Negative hydrogen ions ; Ion source ; Neutral beam injection ; RF source
- 刊名：Chemical Physics
- 出版年：2012
- 期刊代码：18_03010104
- 类别：ch
- 出版时间：4 April, 2012
- 卷：398
- 期：Complete
- 页码：7-16
- 文件大小：1658 K
摘要
Large and powerful negative hydrogen ion sources have to be developed for the neutral beam injection system of the international fusion experiment ITER which is currently under construction. In order to fulfil the ITER requirements 鈥?high negative ion current densities and low co-extracted electron currents at low pressure operation (0.3 Pa) 鈥?caesium is seeded into the discharges which lowers the work function of the converter surface. The paper addresses the development program at the three test facilities of the Max-Planck-Institut f眉r Plasmaphysik (IPP) in Garching. Emphasis is given on a comparison of deuterium with hydrogen operation as well as on the complex caesium chemistry and the plasma surface interaction which are at present the most critical issues for optimising the source performance. An insight into the plasma chemistry and the processes relevant for source optimisation is provided by the well diagnosed plasma accompanied by modelling which is strongly coupled to the physics relevant for the experiments.