激光等离子体非平衡X射线发射谱理论研究

INVESTIGATION ON NON-EQUILIBRIUM X-RAY EMISSION SPECTRA FROM LASER PRODUCED PLASMAS

在平均离子模型的基础上,发展了一个计算离子组态概率分布的有效方法,称为统计方法.根据激光靶耦合程序模拟给出腔靶等离子体状态条件,研究1.06μm激光金等离子体的非平衡离子组态分布和X射线发射谱特性.得到与实验谱相同的能带范围,并得出在激光等离子体中多电子同时处于激发态的离子组态对X射线发射的贡献不能忽略的结论.

A statistical method for the ion configuration probability distribution in non-LTE plasmas based on the average-ion model is described. In this method, the ion configuration probabilities are obtained from the average level population probabilities of the ions according to the binomial distribution. The non-equilibrium ion configuration distribution and X-ray spectra emitted from Au plasmas produced by 1.06 μm laser are studied. The calculated X-ray emission spectra are in the same energy band range as the experimental results. We discuss the non-equilibrium characteristics of X-ray emission, and show that the contributions of the multiply excited ions to X-ray emission are important.