Relativistic Electron Magneto Hydrodynamics (E-MHD)

为了研究超强激光等离子体相互作用产生的高密度相对论电子的电磁现象，开发了粒子模拟程序和流体-粒子桥模拟程序。通过将仿真结果与相应的实验数据进行比较，对所开发的仿真代码进行了测试。实际上，高密度相对论电子可以引起韦伯不稳定性，并产生强磁场，使电子流分裂成许多细丝。我们还利用大尺度三维粒子模拟研究了相对论激光等离子体相互作用。通过相对论非线性相互作用，激光脉冲产生调制和模拟的拉曼耦合不稳定性，并分裂成细丝或孤立脉冲。作为强激光脉冲调制的结果，电子被加速到高于10 MeV。当这些相对论性电子进入过密等离子体时，会引起强烈的磁场涨落，在这种E-MHD湍流中，涨落谱发生逆级联，出现电子流结构。这些电子流的自组织行为将对快点火堆芯等离子体的加热起到至关重要的作用。在超强激光等离子体中，稠密相对论电子动力学在X射线产生、高能离子产生等方面也有重要作用。

In order to clarify the electro magnetic phenomena of high density relativistic electron which is produced by ultra intense laser plasma interactions, a particle simulation code and a fluid - particle by brid simulation code have been developed. The developed simulation codes were tested by comparing simulation results with corresponding experimental date. Actually, it was found that a high density relativistic electron could induces Weibel instability and generates strong magnetic fields to break up the electron flow into many filaments. It was also found that the well developed filaments interact strongly with each others and they are merged into longer scale filaments.In this research, we also studied the relativistic laser plasma interaction by a large scale three dimensional particle in cell simulation. By the relativistic nonlinear interactions, the laser pulse induces modulation and simulated Raman coupled instability and break up into filaments or solitary pulses. As the results of strong laser pulse modulation, electrons are accelerated to high to higher than 10 MeV. When those relativistic electrons penetrate into over dense plasmas, the strong magnetic field fluctuation are induced.In this E-MHD turbulence, the inverse cascade of the fluctuation spectrum occurs and electron flow structures appear. Those self-organized behavior of the electron flow will have crucial efforts on the heating of fast ignition core plasma. The dense relativistic electron dynamics is also found to be important in X-ray generation, high energy ion generation, and so on in ultra - intense laser plasmas.