电场磁场平行型中性粒子分析器剥离单元和分析单元的设计与模拟

doi:10.16568/j.0254-6086.202301013

摘要/Abstract

摘要： 介绍了电场磁场平行型中性粒子分析器(E//B NPA)的剥离单元和分析单元的结构设计。剥离单元由剥离室(包括两个差分管和供气波纹管)、真空室(包括一个中性粒子进入孔和一个离子排出孔)和真空抽气系统组成。计算了分析器的剥离效率，用综合效率的形式 R×f₊₁ 表示，R 是透射率，f₊₁ 是电荷态为+1 的粒子的比例。E//B NPA 的分析磁场由永磁铁、磁极和磁轭构成的磁体来实现，永磁铁的材料是 NdFeB，磁极和磁轭的材料是低碳钢。磁极采用收口式设计，以聚焦离子的飞行轨迹，并提高磁场的利用率。通过对电磁场中带电粒子飞行轨迹的模拟，观察到 H⁺ 和 D⁺ 在探测面上的离子轰击点分为上下两行，并分别按照能量由低至高从左到右排布。所模拟 H⁺ 和 D⁺ 的能量范围分别为 20~200keV 和 10~200keV，可以满足 HL-2A 和 HL-2M 装置上中性束注入加热等离子体时快离子质谱和能谱的诊断需求。

关键词: 中性粒子分析器；快离子；剥离单元；分析单元；粒子飞行轨迹

Abstract: The neutral particle analyzer with parallel electric and magnetic field (E//B NPA) is introduced, which is capable of both mass and energy resolution. The development of the NPA mainly includes the structural designs of the stripping unit and the analysis unit. The stripping unit is composed of a stripping room (equipped with two differential tubes and a gas supply bellows), a vacuum chamber (with a neutral particle entrance hole and an ion exit hole) and a vacuum pumping system. The stripping efficiency is calculated in the form of global efficiency R×f₊₁, where R is the transmission rate and f₊₁ is the fraction of plus one charge state. The analytical magnetic field of the E//B NPA is produced with the magnet composed of the permanent magnet, pole and yoke. The yoke and the poles are made of mild steel and the permanent magnet is made of NdFeB. The magnetic poles are specially designed to focus the ion trajectories and to increase the usage of the magnetic field. In the charged particle trajectory simulation, the H⁺ and D⁺ ion hitting points distribute in two straight lines at the detector plane. The energy of the ions increases as the hitting position changes from left to right. The energy ranges in the simulation are 20~200keV for H+ and 10~200keV for D⁺ , respectively. This satisfies the diagnostic demand for the mass spectrum and energy spectrum of fast ions in neutral beam injection heating plasmas on HL-2A and HL-2M tokamaks.

Key words: Neutral particle analyzer, Fast ions, Stripping unit, Analysis unit, Particle trajectory

中图分类号:

TL62+ 6

屈玉凡, 臧临阁, 林炜平, 罗圆. 电场磁场平行型中性粒子分析器剥离单元和分析单元的设计与模拟[J]. 核聚变与等离子体物理, 2023, 43(1): 75-81.

QU Yu-fan , ZANG Lin-ge , LIN Wei-ping , LUO Yuan. Design and simulation of the stripping unit and the analysis unit of a parallel electric and magnetic field NPA[J]. Nuclear Fusion and Plasma Physics, 2023, 43(1): 75-81.

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