Abstract: Using AMC program, the frequency variation characteristics of reverse shear Alfvén eigenmodes 
(RSAE) under different safety factors are obtained. When the minimum of q-profile q_min >1, the frequency of 
RSAE increases with the increase of q_min , and the frequency of RSAE increases with the decrease of q_min when 
q_min <1, which is consistent with the frequency given by simplified RSAE dispersion relation. In HL-2A 
experiment, the up-sweeping mode was found in the case of q_min >1 and q_min <1 during the current ramp-up and 
sawtooth phase, respectively. The frequencies of these modes are between the toroidal Alfvén eigenmodes and the 
beta-induced Alfvén eigenmodes, which are identical with the frequency of the RSAE modes obtained with AMC. 
The radial mode structure consists of a single poloidal harmonic wave and is highly localized nearby q_min , which 
is the typical characteristics of RSAE. 

Key words: Reverse shear Alfvén eigenmode, Safety factor, HL-2A tokamak 

摘要： 利用 AMC 程序获取了不同最小安全因子( q_min )情况下反剪切阿尔芬本征模频率(RSAE)的变化特征：
当最小安全因子 q_min >1 时，RSAE 频率随着 q_min 增大而增大；当 q_min <1 时，RSAE 频率随着 q_min 减小而增大。这
与简化 RSAE 色散关系给出的频率相符。在 HL-2A 电流爬升期间和锯齿期间分别发现了 q_min >1 和 q_min <1 情况下
缓慢向上扫频的模。这些模的频率介于环向阿尔芬本征模和比压阿尔芬本征模之间，与 AMC 得到的 RSAE 模频
率一致，模的径向结构由单一极向谐波组成，并且高度局域在 q_min 附近，具有典型的 RSAE 特征。

关键词: 反剪切阿尔芬本征模；安全因子；HL-2A 装置