Research on the Discharge Simulation of Radio Frequency Ion Source for EAST Neutral Beam Injector

Neutral beam injection (NBI) is one of the most efficient means of four auxiliary plasma heating means and has been applied to drive current in nuclear fusion physics studies. The high current ion source is one of the key components of neutral beam injector, its performance determines the achievable goals of the EAST NBI. For the purpose of satisfying long pulse operation and the future demands of high energy ion source of NBI, the RF ion source was developed and studied to replace the traditional hot cathod ion source. This paper aims to study the fundamental physical characteristics of radio frequency plasma discharge. Two-dimensional inductively coupled plasma model is used to carry out numerical simulation for RF ion source. The simulation results give the optimal parameters of the RF ion source for EAST NBI. And the relationship between discharge characteristics and air pressure and power are analyzed. Conclusion: The simulation results lay a foundation for the development and experimental study of RF ion source.

中性束注入（Neutral beam injection, NBI）是四大辅助等离子体加热手段中效率最高的方式之一，已被应用于核聚变物理研究中的电流驱动领域。强流离子源是中性束注入器的关键部件之一，其性能决定了EAST NBI可实现的研究目标。为满足长脉冲运行需求以及中性束注入器未来对高能离子源的技术要求，研究人员开发并研究了射频离子源（RF ion source），以替代传统的热阴极离子源。本文旨在研究射频等离子体放电的基本物理特性，采用二维感应耦合等离子体模型对射频离子源开展数值模拟。模拟结果给出了适用于EAST NBI的射频离子源最优参数，并分析了放电特性与气压、功率之间的关联关系。结论：本模拟结果为射频离子源的研发与实验研究奠定了基础。