Abstract

A pulsed source of ions with ionization of the substance under study at atmospheric pressure by the UV radiation of laser plasma is numerically simulated. The calculations are based on an original mathematical model that describes evolution of an ensemble of ions in the presence of superimposed gas-dynamic and electric fields with allowance for the Coulomb interaction. The model contains a system of the Navier–Stokes equations for gas-dynamic flows in the volume under study, the Poisson equation for the resulting distribution of electric field in such a volume, and the Lorentz equation for construction of ion trajectories from the ionization place to collecting diaphragm. Convergence of the relaxation method is demonstrated for the numerical solution of the main model equations. The dependence of ion current on applied voltage is studied. It is shown that the calculated results are in good agreement with the experimental data when finiteness of the ion lifetime due to recombination effect is taken into account.

中文翻译：

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激光等离子体辐射引起电离的大气源中的离子动力学

摘要

在大气压下，通过激光等离子体的紫外线辐射，对正在研究的物质进行电离的脉冲离子源进行了数值模拟。这些计算基于原始数学模型，该模型描述了在存在库仑相互作用的情况下，存在叠加的气体动力和电场时离子整体的演化。该模型包含一个用于研究的体积中的气体动力学流动的Navier-Stokes方程组，用于在该体积中产生的电场分布的Poisson方程以及用于从电离位置构造离子轨迹的Lorentz方程收集隔膜。对于主模型方程的数值解，证明了松弛方法的收敛性。研究了离子电流对施加电压的依赖性。