Physics and engineering design of 400 keV H- accelerator for negative ion based neutral beam injection system in China

A research project of the CFETR Negative ion-based Neutral Beam Injection (NNBI) prototype has be started in China. The objectives of the CFETR NNBI prototype are to produce a negative hydrogen ion beam of >20 A up to 400 keV for 3600 s and to attain a neutralization efficiency of >50%. In order to identify and optimize the design of the negative ion accelerator, a self-consistent model has been developed to consider all key physics and engineering issues (electric and magnetic field, background gas flow, beam optics, beam-gas interaction, secondary particles trajectories, power deposition on grids, heat removal design, and mounting pattern). This paper presents the primary results by applying the self-consistent model to the current design of the 400 keV H- accelerator of the CFETR NNBI prototype.

中国已启动CFETR负离子中性束注入（NNBI）原型装置的研究项目。该CFETR NNBI原型装置的目标是产生束流强度大于20安、能量高达400千电子伏、持续时间3600秒的负氢离子束，并实现超过50%的中和效率。为确定并优化负离子加速器的设计，研究人员开发了一个自洽模型（self-consistent model），以考虑所有关键物理与工程问题，包括电场与磁场、背景气流、束流光学、束流-气体相互作用、次级粒子轨迹、栅极功率沉积、热移除设计及安装模式等。本文介绍了将该自洽模型应用于CFETR NNBI原型装置400千电子伏负氢离子加速器当前设计所得到的初步结果。