Scenarios for the nonlinear evolution of alpha-particle-induced Alfvén wave instability.
Scenarios for the nonlinear evolution of alpha-particle-induced Alfvén wave instability.
复制标题
DOI：
10.1103/physrevlett.68.3563
复制
发表时间：
1992-03
影响因子：
8.6
通讯作者：
H. L. Berk;B. Breizman;H. Ye
中科院分区：
文献类型：
--
作者：
H. L. Berk;B. Breizman;H. Ye
各种非线性的情况下，给出了高能粒子的演化，这些粒子在背景等离子体中减慢，同时引起背景等离子体波的不稳定性。如果背景阻尼足够弱，则如Berk和Breizman所述建立稳态波。对于较大的背景阻尼率脉动发展。当波幅上升到陷波频率等于增长率时，就会出现饱和。然后，波阻尼由于小的背景耗散存在和一个相对较长的安静的间隔之间存在的爆发，而自由能的分布是由经典的运输重新填充。在这种情况下，由于扩散的高能粒子的异常能量损失相比，与背景等离子体的经典碰撞能量交换是小的。然而，如果在捕获频率下，波振幅大到足以引起轨道随机性，则在波振幅上升到更高水平的情况下发生相空间"爆炸“，这导致高能粒子的快速损失。
Various nonlinear scenarios are given for the evolution of energetic particles that are slowing down in a background plasma and simultaneously causing instability of the background plasma waves. If the background damping is sufficiently weak, a steady-state wave is established as described by Berk and Breizman. For larger background damping rate pulsations develop. Saturation occurs when the wave amplitude rises to where the wave trapping frequency equals the growth rate. The wave then damps due to the small background dissipation present and a relatively long quiet interval exists between bursts while the free energy of the distribution is refilled by classical transport. In this scenario the anomalous energy loss of energetic particles due to diffusion is small compared to the classical collisional energy exchange with the background plasma. However, if at the trapping frequency, the wave amplitude is large enough to cause orbit stochasticity, a phase space ``explosion`` occurs where the wave amplitudes rise to higher levels which leads to rapid loss of energetic particles.