Demagnetization of electrons in the electromagnetic field structure, typical for quasi‐perpendicular collisionless shock front
Demagnetization of electrons in the electromagnetic field structure, typical for quasi‐perpendicular collisionless shock front
复制标题
电磁场结构中电子的退磁，典型的准垂直无碰撞激波锋面
DOI：
10.1029/94ja03369
复制
发表时间：
1995
影响因子：
--
通讯作者：
V. Krasnosselskikh
中科院分区：
文献类型：
--
作者：
M. Gedalin;K. Gedalin;M. Balikhin;V. Krasnosselskikh
我们考虑电子在电磁场结构中的运动，这种电磁场结构是准垂直无碰撞激波的斜坡的典型结构。一个电子由于穿过静止激波阵面而获得的总能量由de Hoffman-Teller坐标系中的交叉激波势决定。当激波较宽时，电子被电场沿着磁场加速，而垂直方向的能量增益是绝热的电子能量增益B。然而，如果斜坡足够窄，电子被有效地退磁，并且相当大一部分的交叉冲击势能可以直接转移到电子垂直能量中，从而导致显著的过绝热磁共振。这种效应可能与超临界冲击中电子的强烈加热密切相关。
We consider the motion of electrons in the electromagnetic field structure which is typical for the ramp of the quasi-perpendicular collisionless shock. The total energy that an electron can gain due to the crossing of the stationary shock front is determined by the cross-shock potential in the de Hoffman-Teller frame. When the shock is wide the electrons are accelerated by the electric field along the magnetic field, while the perpendicular energy gain is adiabatic υ⊥² ∝ B. If, however, the ramp is narrow enough, the electrons are effectively demagnetized, and a considerable fraction of the cross-shock potential energy can be transferred directly into the electron perpendicular energy, causing substantial overadiabatic energization. This effect may be closely related to the strong heating of electrons in the supercritical shocks.