假定烧蚀粒子与环境气体原子均为刚性硬球,采用蒙特卡罗(Monte Carlo)方法,对单脉冲激光烧蚀产生的硅(Si)粒子在1000 Pa环境氦(He)气中的传输过程进行了数值模拟,研究了衬底对环境密度恢复时间的影响。结果发现,衬底对粒子完全反弹和完全吸附的情况下对应的环境密度恢复时间分别为1713.2 μs和1663.2 μs,并且随着衬底对粒子临界吸附速度的增大,环境密度恢复时间先增大后减小。

Ablated particles and ambient gas atoms are assumed to be rigidity-spheres. In order to investigate the influence of substrate on the density-reversion time of environment,the propagation of Si particles generated by single pulsed laser ablation through ambient He gas with 1000 Pa is simulated via Monte Carlo method. The results show that the density-reversion time of the environment is 1713.2 μs and 1663.2 μs respectively when the Si particles are absorbed and rebounded completely by substrate. With increasing critical adsorbing velocities of the substrate,the density-reversion time firstly increases and then decreases.