Linear properties of energetic particle modes with m/n=1/1 driven by passing fast ions

doi:10.16568/j.0254-6086.202601014

Abstract

Abstract:

The study of magnetohydrodynamic instabilities driven by fast particles has been a prominent focus in magnetic confinement fusion research. The effects of the fast ion beta, local magnetic shear, core safety factor and initial velocity of fast ions on the linear instability of energetic particle modes are numerically analyzed using the experimental parameters of HL-2A tokamak. It is shown that the fast ion beta enough large will drive m/n=1/1 instability, and the mode structure is similar to the kink mode or the interchange mode (depending on the plasma parameters), where, m and n are the poloidal and toroidal mode number,respectively. When the magnetic shear is weak, the mode growth rate is less dependent on the fast ion beta, and the mode is more easily excited.The initial velocity of the fast ion is directly proportional to the growth rate and frequency of the mode, and the large initial velocity corresponds to a wider mode structure, which is different from the instability driven by the trapped particles.

Key words:

Passing fast ions, Magnetohydrodynamics, Instability, Energetic particle modes

摘要：

快粒子驱动的各种磁流体不稳定性一直是磁约束核聚变物理领域的关注焦点。采用 HL-2A 装置实验参数，理论推导了模式的本征方程，并数值分析了通行快离子比压、局部磁剪切、快离子的初始速度等参数对高能量粒子模的线性不稳定性的影响。研究表明，当通行快离子比压值较大时，m/n=1/1 不稳定性将被激发，其结构类似于扭曲模或交换模(取决于等离子体参数)，这里 m 和 n 分别为极向和环向模数；当磁剪切较弱时，快离子比压对频率几乎无影响，且模式更容易被激发；增长率和频率与快离子的初始速度呈正比关系，大的初始速度导致模结构展宽，这与捕获粒子驱动的不稳定性结果有所不同。

关键词:

通行快离子, 磁流体, 不稳定性, 高能量粒子模

CLC Number:

O534

GUO Wen-tao , WANG Xian-qu , SU Xiang , XU Yu-hong , CHENG Jun , LIU Hai-feng , HUANG Jie , ZHANG Xin , LIU Hai , TANG Chang-jian. Linear properties of energetic particle modes with m/n=1/1 driven by passing fast ions[J]. Nuclear Fusion and Plasma Physics, 2026, 46(1): 89-96.

郭文韬, 王先驱, 苏祥, 许宇鸿, 程钧, 刘海峰, 黄捷, 张欣, 刘海, 唐昌建 . 通行快离子驱动的 m/n=1/1 高能量粒子模的线性不稳定性研究[J]. 核聚变与等离子体物理, 2026, 46(1): 89-96.

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