The evolution of electron overdensities in magnetic fields
The evolution of electron overdensities in magnetic fields
复制标题
磁场中电子过密度的演变
DOI：
10.1088/1367-2630/11/6/063001
复制
发表时间：
2009
影响因子：
3.3
通讯作者：
H. Potts
中科院分区：
文献类型：
--
作者：
C. MacLachlan;D. Diver;H. Potts
当中性气体撞击静止的磁化等离子体时，当中性气体超过阈值速度时，电离速率会增加。这通常被称为临界电离速度效应。这个过程有两个截然不同的时间尺度：离子中性碰撞时间和电子加速时间。我们研究了在外加磁场中，电子系综的自电场对它们的能化作用。模拟了电子在不同磁场和密度条件下的演化过程。研究发现，在一定条件下，电子可以加速到电子碰撞电离的速度。在磁控情况下，激发电子的能量分布表明，通常1%的电子布居可以超过与不平衡的电子系综相关的初始静电势。
When a neutral gas impinges on a stationary magnetized plasma an enhancement in the ionization rate occurs when the neutrals exceed a threshold velocity. This is commonly known as the critical ionization velocity effect. This process has two distinct timescales: an ion–neutral collision time and electron acceleration time. We investigate the energization of an ensemble of electrons by their self-electric field in an applied magnetic field. The evolution of the electrons is simulated under different magnetic field and density conditions. It is found that electrons can be accelerated to speeds capable of electron impact ionization for certain conditions. In the magnetically dominated case the energy distribution of the excited electrons shows that typically 1% of the electron population can exceed the initial electrostatic potential associated with the unbalanced ensemble of electrons.