激光等离子体羽辉膨胀的流体动力学模型及数值模拟

Analytical hydrodynamic model of laser induced plasma plume expansion and simulation

基于流体动力学方程组,假定激光烧蚀固体靶材所形成对称膨胀的等离子体羽辉处于定态,将偏微分方程组简化为一组常微分方程,并对方程组进行归一化处理,采用牛顿迭代法进行数值求解,得到了定态膨胀的激光诱导等离子体羽辉的电子温度、膨胀速度和密度空间分布的基本规律,数值求解结果与实验观测现象是相一致的.通过物理量的归一化处理,该理论模型将激光等离子体羽辉膨胀的过程标准化,方便和实验数据的对比分析,有助于理解激光等离子体羽辉膨胀的动力学过程.

This paper was based on the hydrodynamic equations and steady state assumptions of the laser induced plasma plume.The partial difference equations were simplified into a set of ordinary equations which could be normalized by the characteristic parameters.The profiles of density,temperature,and velocity of the steady state laser induced plasma plume were obtained by using the Newton iteration numerical method.The simulation results had a fair agreement with the experimental data.The process of the laser produced plasma expansion was standardized by the normalized physical quantity.These results provide useful guides to understand the properties of the laser produced plasma plume by compariing of the experimental data.