Two types of helical-core equilibrium states in tokamak plasmas
Two types of helical-core equilibrium states in tokamak plasmas
复制标题
托卡马克等离子体中两种类型的螺旋核平衡态
DOI：
10.1088/1361-6587/ac828c
复制
发表时间：
2022
影响因子：
2.2
通讯作者：
Nakamura Y
中科院分区：
文献类型：
--
作者：
Kawagoe S;Ishizawa A;Aiba N;Nakamura Y
利用三维磁流体力学（MHD）平衡计算和稳定性分析，研究了弱反向磁剪切托卡马克等离子体核心区的螺旋畸变及其形成机制。发现存在两种不同类型的螺旋平衡状态：一种是磁芯区域在极向截面上的刚体位移，另一种是仅围绕磁轴的局部平流。对相应的轴对称平衡进行了线性稳定性分析，以了解这两种螺旋平衡状态的起源。分析表明，前者与电流驱动的内扭结不稳定性有关，后者与压力驱动的准交换不稳定性有关。当安全系数达到最小值时，出现扭结模式驱动的螺旋平衡状态
Helical distortion in the core region and its formation mechanism in weakly reversed magnetic shear tokamak plasmas are investigated using three-dimensional magnetohydrodynamic (MHD) equilibrium calculations and MHD stability analysis. It is found that there are two different types of helical equilibrium states: one is a rigid-body shift in the core region on a poloidal cross-section, while the other is a local advection only around the magnetic axis. Linear stability analysis of the corresponding axisymmetric equilibrium is carried to understand the origin of these two types of helical equilibrium states. The analysis shows that the former is related to the current-driven internal-kink instability, while the latter is linked to the pressure-driven quasi-interchange instability. The kink-mode-driven helical equilibrium state appears when the minimum value of the safety factor