论文标题
Sawteeth安全系数的演变
Evolution of safety factor profiles in sawteeth
论文作者
论文摘要
采用两个不同的安全系数定义来研究正常sape虫，固定态和不完整重新连接期间安全系数的演变。发现旧定义的安全系数有时与Sawteeth期间的磁场的繁殖力图不一致。旧的安全系数始终表明磁轴周围的安全系数随着扭结不稳定性的发展而等于1.0。但是，磁场线的繁殖图表明磁轴周围的磁场拓扑尚未更改。为了解决不一致，我们提出了对安全因子的新定义，其中使用相对于新的扭曲磁轴而不是与原始轴的螺栓角度。有了新的定义，安全系数概况与磁场的繁殖力图一致。我们还发现，安全因子概况与两个不同的Q定义显着不同。有了新的Q定义，磁轴Q0处的安全系数几乎在整个锯齿齿中保持不变，并且在正常sawteeth期间在末端的末端跳至1.0。在非轴对称平衡中，Q0仍低于1.0； Q0在整个不完整的重新连接过程中仍然是其初始值。
Two different definitions of the safety factor are applied to investigate the evolution of the safety factor profile during normal sawteeth, the stationary state, and the incomplete reconnection. It is found that the safety factor profiles from the old definition are sometimes inconsistent with the Poincare plots of the magnetic field during sawteeth. The old safety factor always indicates that the safety factor around the magnetic axis is flattened and equal to 1.0 with the development of the kink instability. However, the Poincare plots of the magnetic field lines indicate that the topology of the magnetic field around the magnetic axis has not been changed. To solve the inconsistency, we propose a new definition of the safety factor, in which the poloidal angle relative to the new twisted magnetic axis is used instead of the poloidal angle to the original axis. With the new definition, the safety factor profiles are consistent with Poincare plots of the magnetic field. We also find that the safety factor profiles are significantly different from the two different q definitions. With the new q definition, the safety factor at the magnetic axis q0 remains unchanged in almost the entire period of a sawtooth and jumps up to 1.0 near the end during normal sawteeth; in the non-axisymmetric equilibrium, q0 is still far below 1.0; q0 remains its initial value throughout the incomplete reconnection.
