Investigation of Beta-Induced Alfven Eigenmode during Strong Tearing Mode Activity in the HL-2A Tokamak

被引：19

作者：

Chen Wei ^{[1
]}

Ji Xiaoquan ^{[1
]}

Yang Qingwei ^{[1
]}

Ding Xuantong ^{[1
]}

Liu Yi ^{[1
]}

Feng Beibin ^{[1
]}

Huang Yuang ^{[1
]}

Li Wei ^{[1
]}

Zhou Yan ^{[1
]}

Zhou Jun ^{[1
]}

Song Xianming ^{[1
]}

Li Liancai ^{[1
]}

Duan Xuru ^{[1
]}

机构：

[1] SW Inst Phys, Chengdu 610041, Peoples R China

来源：

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN | 2010年 / 79卷 / 04期

关键词：

BAE; CAP; island width; Alfven velocity; DIII-D TOKAMAK; WAVES; EXCITATION; PLASMAS; TFTR;

D O I：

10.1143/JPSJ.79.044501

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The beta-induced Alfven eigenmode (BAE) excited by large m/n = 2/1 magnetic islands has been recently observed on HL-2A. The frequencies of these oscillations range from 15 to 35 kHz, and is provided with the same order of the low-frequency gap induced by finite beta effects. The magnetic fluctuation spectrogram indicates that the BAEs often occur in pairs. The analysis reveals that the modes propagate poloidally and toroidally in opposite directions, and form standing-wave structures in the island rest frame. The frequencies of the pair mode are associated with the Te/Ti ratio, Alfven velocity and island width, and the frequency difference of the pair modes is determined by the frequency of tearing mode. Note to point out that the BAE frequency is influenced by the Te/Ti ratio. The island width has been evaluated quantitatively, and the island width threshold of BAE excitation has been found by using statistical analysis method. The threshold w(c) is about 3.4 cm on HL-2A, and the BAE can be driven while the width island exceeds the threshold w(c).

引用

页数：6

共 23 条

[1] Excitation of beta-induced Alfven eigenmodes in the presence of a magnetic island [J].