Kemp A J, Sentoku Y, Sotnikov V, Wilks S C
Department of Physics, University of Nevada, Reno, Nevada 89557, USA.
Phys Rev Lett. 2006 Dec 8;97(23):235001. doi: 10.1103/PhysRevLett.97.235001. Epub 2006 Dec 4.
Energy relaxation of the hot electron population generated by relativistic laser pulses in overdense plasma is analyzed for densities ranging from below to 1000 times solid density. It is predicted that longitudinal beam-plasma instabilities, which dominate energy transfer between hot electrons and plasma at lower densities, are suppressed by collisions beyond solid density. The respective roles of collisional energy transfer modes, i.e., direct collisions, diffusion, and resistive return current heating, are identified with respect to plasma density. The transition between the kinetic and the collisional regimes and scalings of collisional process are demonstrated by a fully integrated one-dimensional collisional particle simulation.
针对从低于固体密度到固体密度1000倍的密度范围，分析了相对论激光脉冲在过密等离子体中产生的热电子群体的能量弛豫。据预测，在较低密度下主导热电子与等离子体之间能量转移的纵向束 - 等离子体不稳定性，在超过固体密度时会被碰撞抑制。关于等离子体密度，确定了碰撞能量转移模式（即直接碰撞、扩散和电阻回流电流加热）各自的作用。通过一个完全集成的一维碰撞粒子模拟，展示了动力学和碰撞区域之间的转变以及碰撞过程的标度。
