旋转圆柱等离子体中撕裂模和Kelvin-Helmholtz不稳定性的激发特性  

Excitations of tearing mode and Kelvin-Helmholtz mode in rotating cylindrical plasmas

作　　者：毕海亮 魏来[1] 范冬梅[1] 郑殊[1] 王正汹[1] 

机构地区：[1]大连理工大学、三束材料改性教育部重点实验室、物理与光电工程学院,大连116024 [2]中国航天系统科学与工程研究院,北京100048

出　　处：《物理学报》2016年第22期248-255,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11322549,11275043,11305027);大连市杰出人才基金(批准号:2015R001);中央高校基本科研业务费专项资金(批准号:DUT14RC(3)157,DUT15YQ103)资助的课题~~

摘　　要：采用约化的磁流体力学模型,数值研究了柱位形等离子体中q剖面和极向旋转剖面对q=1撕裂模不稳定性和Kelvin-Helmholtz(K-H)不稳定性的影响.随着旋转强度的增加,m/n=1/1模被逐渐抑制,而高阶谐波模式(如m/n=2/2,m/n=3/3等)会经历四个区间:撕裂模失稳区间、撕裂模致稳区间、稳定窗口区间和K-H不稳定性激发区间.更进一步,我们发现,m/n=1/1模的增长率随旋转强度的改变与剪切层所处位置有关,并且剪切层分布在有理面内外的结果基本一致;然而高阶谐波模式却没有此类现象.另外,有理面处磁剪切越小,撕裂模越容易被剪切流抑制,并且越容易激发K-H不稳定性.The influences of safety factor q profile and poloidal rotation profile on the q=1 tearing and Kelvin-Helmholtz（K-H） instabilities are investigated numerically by using a magnetohydrodynamic model in cylindrical geometry.With increasing the poloidal rotation,the m/n=1/1 mode is suppressed,while four domains exist for the high-order harmonic modes（such as m/n=2/2,m/n=3/3）：the destabilized tearing mode domain,stabilized tearing mode domain,stablewindow domain,and unstable K-H mode domain.Further,we find that the growth rate of the m/n=1/1 mode is related to the location of shear layer.Roles of shear flow in the m/n=1/1 mode for the shear layer located t on both the inner and outer sides of rational surface are almost the same,which is different from the scenarios of high-order harmonic modes.In addition,the smaller the magnetic shear on the rational surface,the smaller the growth rate of tearing mode is,and the more easily the K-H instability is excited.

关 键 词：q剖面 旋转剖面 撕裂模不稳定性 KELVIN-HELMHOLTZ不稳定性 

分 类 号：O53[理学—等离子体物理]