Theoretical model of quasi static magnetic field generation and energy transport in the relativisitic laser-plasma interactions

在相对论激光脉冲与固体密度等离子体相互作用过程中，在过密等离子体表面产生了强准静态磁场。表面沿着的磁场抑制了电子向等离子体中的传播。我们研究了磁场的产生和激光到等离子体的能量传输机制，为了研究磁场的产生和激光在等离子体表面的吸收，我们开发了一维和二维完全相对论电磁粒子模拟程序。提出了一个磁场产生的理论模型，即相对论激光脉冲产生的高能电子被固体密度中的高能电子和体电子维持的准静态磁场捕获。通过PIC模拟，验证了理论模型的正确性。结果表明，正如理论模型所示，几乎所有的高能电子都被自感磁场捕获。一些能量大于临界能量的电子穿过表面，临界能量取决于入射激光的强度和入射角。电子流在等离子体内部和靶后表面产生准静态磁场，提出了强激光等离子体相互作用的热电子温度和电子谱的标度，并用PIC模拟验证了标度。

Strong quasistatic magnetic fields at the surface of overdense plasmas are generated during the interaction of a relativistic laser pulse with solid density plasmas. The magnetic fields along the suface inhibit the propagetion of electrons into the plasma. We study the mechanisms of the magnetic field generation and the energy transport from the laser light to the plasma.In order to investigate the magnetic field generation and laser light absorption at the plasma surface we developed one- and two-dimensional fully relativistic electromagnetic particle-in-cell (PIC) simulatiuon codes. We propose a theoretical model of the megnetic field generation.High-energy electrons generated by the relativistic laser pulse are trapped by the quasistatic magnetic field that is sutained by the high-energy electron and bulk electrons in the solid denisty. Using the PIC simulatiuon, we verified the thoretical model. As a result, almost high-energy electrons are trapped by the self-induced magnetic field as the theoretical model shows. Some electron which has more energy than a critical energy, which depends on the insident laser intensity and insident angle, pass through the surface. The electon current generates quasistatic magneteic fields at the inner plasma and rear surface of the target.We proposed the scaling of the hot electron temperature and the electron spectrum of intense laser plasma interaction and verified the scaling using the PIC simulatiuon.