Theoretical Research on Relativistic Interaction of Ultra-Intense Laser Light with High Density Plasmas

这项工作包括分析和计算的研究都正在进行积极的国际合作。分析研究：一个一般的理论是建立在一维稳态传播的高强度圆极化电磁波的相对论效应在过临界密度等离子体。本文从电磁波谱函数的动力学方程出发，分析了短脉冲激光的传输特性，并在充分考虑相对论效应的情况下，导出了电磁波的一般色散关系。导出了非势有质动力，证明了它产生的低频磁场以及由此产生的电子涡和等离子体喷流的形成。计算研究：对激光与非均匀等离子体的相对论相互作用进行了二维模拟，证实了MeV能量等离子体粒子的产生。在局域密度腔中捕获的电磁波以爆发形式发射，并证明了电子与光场共振时的随机加速。2-并对超高强度激光脉冲与慢非均匀等离子体的相对论相互作用进行了三维数值模拟。激光传输通道是由自聚焦或偏转和电子加速产生的，各种不稳定性，电流片的形成，准静态磁场的产生，它们分裂成细丝和合并，快速电子流穿过磁场的异常传输以及由此产生的电流与返回电流的中和被证明。还公开了通过异常电阻率对背景等离子体的异常加热。

This work consists of analytical and computational researches both being conducted by active international collaborations.Analytical Research : A general theory was constructed on the one-dimensional stationary propagation of a high intensity circularly-polarized electromagnetic wave by relativistic effects in over-critical density plasmas. Propagation characteristics of a short pulse laser light is analysed using a kinetic equation for the spectral function of electromagnetic waves and general dispersion relation for electromagnetic waves is derived with full account of relativistic effects. A non-potential ponderomotive force is derived and its generation of low frequency magnetic fields and the resulting electron eddy and plasma jet formation are demonstrated.Computational Research : 2-dimensional simulation for relativistic interaction of laser light with nonuniform plasmas is conducted and production of MeV energy plasma particles is confirmed. Electromagnetic waves trapped in a local density cavity is emitted as bursts and stochastic acceleration of electrons due to resonance with the light field is demonstrqated. 2- and 3-dimensional simulations are carried out on the relativistic interaction of ultra-high intensity laser pulse with slowly nonuniform plasma. Laser propagation channels are produced by self-focusing or filamentation and electron acceleration, various instabilities, current sheets formation, generation of quasi-static magnetic fields, their splitting into filaments and their merging, anomalous transport of fast electron current across magnetic fields and resulting current neutralization with the return current are demonstrated. Anomalous heating of the background plasma by an anomalous resistivity is also disclosed.