无碰撞等离子体中电子束流不稳定性的时空演化研究

Spatio temporal evolution of electron beam instability in collisionless plasmas

应用二、三维相对论电磁粒子模拟程序研究双电子束流在无碰撞等离子体中传播引起的横向电磁 (Weibel类型 )不稳定性和纵向静电不稳定性的发展演化过程 .讨论了纯粹Weibel不稳定性的发生和非线性饱和过程 ,观察到电流束合并、磁场重联等引起的电子横向加热现象 .研究了电流束传播方向激发的静电场对快电子束传播的影响 ,观察到其导致的束的横向调制、磁场通道破坏现象 .对这些过程的细致研究对更好的理解快点火物理中自生磁场的产生、快电子输运等过程有重要意义 .

The spatio temporal evolution of electromagnetic (Weibel-type) and electrostatic (two-stream) instabilities of electron beams propagating in collisionless plasmas were investigated by using electromagnetic relativistic particle-in-cell simulations. The onset and nonlinear saturation of Weibel instability, the emergence of beams and magnetic field reconnection were discussed. The excitation of longitudinal electric field plays an important role for the stable propagation of electron beams, which can be destructed by the transverse modulation due to two-stream instability. These results may be important for understanding the static magnetic field generation and fast electron propagation in fast ignition physics.