Abstract: Based on the experimental observations of beta-induced Alfvén eigenmodes (BAE) in the HL-2A tokamak, the simulation study of BAE has been conducted using the eigenvalue program GAM-solver. The simulated results find that the frequency of BAE is in the range of about 50~70kHz, which increases with the increase of toroidal mode numbers (n). These simulation results are consistent with the experimental observations. Moreover, the mode frequency of BAE with n=3 has been predicted using GAM-solver, and the effects of the main parameters, such as ion-beta (β_i), electron temperature (T_e), and ion temperature (T_i), on the mode frequency of BAE have been studied. The results show that the frequency of the BAE mode is proportional to the square root of β_i; the increase of T_e and T_i will increase the frequency of the accumulation point of the BAE continuum spectrum. The structures of the continuum spectrum and the BAE mode are insensitive to T_e and T_i. The mode frequency increases with the increase of T_e and T_i, which is consistent with the accumulation point frequency of BAE, and the frequency of BAE is more sensitive to T_i.

Key words: Beta-induced Alfvén eigenmode, GAM-solver, Frequency of the BAE accumulation point, Continuum spectrum

摘要： 基于HL-2A装置上比压诱导的阿尔芬本征模(BAE)的实验观测结果，应用本征值程序GAM-solver，对BAE进行了模拟研究。模拟结果表明，BAE的频率大约在50~70kHz范围，且频率随环向模数的增加而增加，这些模拟结果和实验观测一致。同时，应用GAM-solver对环向模数n=3的BAE的模频率进行了预测，研究了主要等离子体参数，比如离子比压(β_i)、电子温度(T_e)以及离子温度(T_i)对BAE模频率的影响。结果表明，BAE模频率同β_i的平方根成正比；T_e和T_i的增大都会使BAE连续谱的积累点频率增大，连续谱的结构和BAE模的结构几乎不随T_e和T_i发生变化，而模频率随T_e和T_i的升高而升高，且与BAE的积累点频率一致，T_i的变化对BAE频率影响更大。

关键词: 比压阿尔芬本征模, GAM-solver程序, BAE积累点频率, 连续谱