39 / 2023-04-06 15:30:19

The nonlocal electron heat transport under the non-Maxwellian distribution in laser plasmas and its influence on laser ablation

laser ICF,Laser Ablation

惯性约束聚变物理学 > 内爆和不稳定性

Electron heat transport is an important issue in laser heated plasmas. It determines the energy distribution in plasmas, so the plasma condition is dependent on the electron heat transport. Electron heat transport plays a crucial role in both indirect drive inertial confinement fusion (ICF) and direct drive ICF. For the plasmas created by intense laser, the traditional Spitzer–Härm theory cannot accurately describe the electron heat transport process mainly due to two physical effects. First, the electron distribution function would significantly differ from the Maxwellian distribution because of the inverse bremsstrahlung heating. Second, the long mean free paths of heat carrying electrons relative to the temperature scale length indicate that the electron heat flux has the nonlocal feature. We have developed a nonlocal electron heat transport model based on the non-Maxwellian electron distribution function (NM-NL model) to describe the electron heat flux in laser plasmas. Recently, this model is successfully incorporated into our radiation hydrodynamical code RDMG. We numerically investigated the electron heat flux in laser plasmas, especially the nonlocal feature of heat flux and the influence of the non-Maxwellian distribution. The influence of electron heat transport on laser ablation is also discussed. The simulated plasma conditions based on different electron heat transport models are presented and compared with experiments. Our results show that the nonlocal feature of heat flux and the influence of non-Maxwellian distribution function are considerable in plasmas heated by intense lasers.