arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1708.04700physics.plasm-ph
收藏

具有平行动力学的实频撕裂层及其对锁模和阻壁模的影响

Real frequency tearing layers with parallel dynamics and the effect on locking and resistive wall modes

John M. Finn, Andrew J. Cole, Dylan P. Brennan

摘要:

在等离子体坐标系中具有实频率的撕裂模式(即,除了由于$E\times B$旋转引起的多普勒频移之外)具有潜在的重要性,因为它们对锁定过程有影响。特别是,它最近被证明[J。Finn,A. J. Cole和D. P. Brennan,Phys. Plasmas(Letters),22:120701,2015],在存在所施加的误差场的情况下等离子体上的麦克斯韦扭矩对于具有接近边缘稳定性的实频率的撕裂模式被显著修改。此外,它是已知的[J。Finn和R. A. Gerwin,Phys. Plasmas,3:2344,1996],如果撕裂模式具有接近边缘稳定性的实频率,则电阻壁撕裂模式可以通过旋转而在其无壁极限以下不稳定。在本文中,我们首先推导出撕裂模色散关系与压力梯度,磁力线曲率和平行动力学的连续惯性(RI)制度,忽略的$E\times B$漂移和垂直电阻率的发散。结果表明,在忽略垂直电阻率和$E\times B$漂移发散的简化模型中,出现了通常的Glasser效应,即包含实频率的环形效应。我们还发现,使用一个类似的简单的模型,令人惊讶的结果,在粘阻制度的压力梯度,有利的曲率由于环形效应,和平行的动力学,一个类似的Glasser-like效应被发现,我们表明,在这两个制度的撕裂模式的存在与复杂的频率附近的静电电阻交换模式与复杂的频率。我们讨论了锁定到一个错误字段的效果和显着降低的门槛不稳定的电阻壁撕裂模式,这可以更明显的比弱的影响,观察到的RI撕裂模式没有压力曲率驱动芬恩和Gerwin,1996年。

英文摘要:

Tearing modes with real frequencies in the plasma frame (i.e. in addition to the Doppler shift due to $E\times B$ rotation) are of potential importance because of their effect on the locking process. In particular, it has recently been shown [J. M. Finn, A. J. Cole, and D. P. Brennan, Phys. Plasmas (Letters), 22:120701, 2015] that the Maxwell torque on the plasma in the presence of an applied error field is modified significantly for tearing modes having real frequencies near marginal stability. In addition, it is known [J. M. Finn and R. A. Gerwin, Phys. Plasmas, 3:2344, 1996] that resistive wall tearing modes can be destabilized below their no-wall limits by rotation, if the tearing modes have real frequencies near marginal stability. In this paper we first derive the tearing mode dispersion relation with pressure gradient, field line curvature and parallel dynamics in the resistive-inertial (RI) regime, neglecting the divergence of the $E\times B$ drift and perpendicular resistivity. The results show that the usual Glasser effect, a toroidal effect which involves real frequencies, occurs in this simplified model, which ignores perpendicular resistivity and the divergence of the $E\times B$ drift. We also find, using a similar simple model, the surprising result that in the viscoresistive regime with pressure gradient, favorable curvature due to toroidal effects, and parallel dynamics, a similar Glasser-like effect is found. We show that in both regimes the existence of tearing modes with complex frequencies is related to nearby electrostatic resistive interchange modes with complex frequencies. We discuss the effect on locking to an error field and the significant lowering of the threshold for destabilization of resistive wall tearing modes, which can be much more pronounced than the weak effect observed for RI tearing modes without pressure-curvature drive in Finn and Gerwin, 1996.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑