文献类型：期刊文献

英文题名：Low-frequency fishbone driven by passing fast ions in tokamak plasmas

作者：Yu, Limin[1];Wang, Feng[2];Fu, G. Y.[3,4];Yu, Liming[5]

机构：[1]East China Univ Sci & Technol, Dept Phys, Shanghai 200237, Peoples R China;[2]Dalian Univ Technol, Sch Phys, Minist Educ, Key Lab Mat Modificat Laser Ion & Electron Beams, Dalian 116024, Peoples R China;[3]Zhejiang Univ, Inst Fus Theory & Simulat, Hangzhou 310027, Zhejiang, Peoples R China;[4]Zhejiang Univ, Dept Phys, Hangzhou 310027, Zhejiang, Peoples R China;[5]Southwestern Inst Phys, Chengdu 610041, Sichuan, Peoples R China

年份：2019

卷号：59

期号：8

外文期刊名：NUCLEAR FUSION

收录：;EI(收录号：20193407334711);WOS:【SCI-EXPANDED(收录号:WOS:000472753400006)】；

基金：One of the authors (Limin Yu) would like to thank the HL-2A team for tokamak device operation. The author would also like to acknowledge Dr. Wei Chen for helpful discussions. This work was supported by Zhejiang University's startup funding for Professor Guoyong Fu, National Natural Science Foundation of China under Grant Nos. 11505022, 11675053, 11875131 and 11875024, National Magnetic Confinement Fusion Science Program of China under Contract No. 2015GB110005, National Key Research and Development Program of China under Contract No. 2017YFE0301202.

语种：英文

外文关键词：low-frequency fishbone; passing fast ions; finite orbit width; energetic particle mode; tokamak plasmas

摘要：Low-frequency fishbone instability driven by passing fast ions via wave-particle resonance omega = omega(phi) - omega(theta) is studied within the framework of energetic particle mode (EPM), where omega(phi) and omega(theta) are toroidal transit frequency and poloidal transit frequency of passing fast ions respectively. The effects of finite orbit width of energetic particles are responsible for the low-frequency fishbone of EPM type. It is found that magnetic shear at the q = 1 radius plays an important role in the instability whereas the effect of background plasma beta is weak. In particular, for the case of co-injection of beam ions, there exists a critical magnetic shear below which the beam ion beta threshold for EPM excitation is very small. For moderate or higher magnetic shear, the beam ion beta threshold is much higher, on order of a few percent. These results are consistent with the observation of the low-frequency fishbone in the HL-2A tokamak.