Lu S M, Zhou F Y, Xie L Y, Ma Y L, Zhao G P, Gao X, Wu Y, Wang J G
Institute of Modern Physics, <a href="https://ror.org/013q1eq08">Fudan University</a>, Shanghai 200433, China.
National Key Laboratory of Computational Physics, <a href="https://ror.org/03sxpbt26">Institute of Applied Physics and Computational Mathematics</a>, Beijing 100088, China.
Phys Rev E. 2024 May;109(5-2):055205. doi: 10.1103/PhysRevE.109.055205.
Complicated many-body interactions between ions and surrounding particles exist in warm and hot dense plasmas. It will significantly alter the atomic structures and dynamic properties of the embedded ions. Recently, the atomic-state-dependent (ASD) screening model has been proposed and shown to be valid for investigating the screening effect in warm and hot dense plasmas over a wide range of electron densities and temperatures. By employing the ASD model, we investigate the photoionization process for the hydrogenlike carbon ion embedded in warm and hot dense plasmas with corresponding Coulomb coupling parameter ranges of 0.05 ≤ Γ ≤ 1.16, where Γ characterizes the ratio of the average potential to thermal energy. It is found that there are stronger plasma screening effects on the ionization energy and photoionization cross section due to the negative-energy electron distributions considered in the ASD model compared to those considering only free electrons. The present results from the ASD model show reasonable agreement with the classical Debye-Hückel (DH) model in weakly coupled plasmas. However, significant deviations of the ionization energy and cross section between these two models are observed in moderately and strongly coupled plasmas, due to the approximate treatment of the plasma-electron density distribution of the DH model. In the region of low photoelectron energies, the positions of the shape resonance peaks of the cross sections obtained from the ASD model differ significantly from those of the DH model due to the different screening effects.
在温热稠密等离子体中存在离子与周围粒子之间复杂的多体相互作用。这将显著改变嵌入离子的原子结构和动态特性。最近，提出了原子态依赖（ASD）屏蔽模型，并表明该模型在研究广泛电子密度和温度范围内的温热稠密等离子体中的屏蔽效应时是有效的。通过采用ASD模型，我们研究了嵌入温热稠密等离子体中的类氢离子的光电离过程，相应的库仑耦合参数范围为0.05≤Γ≤1.16，其中Γ表征平均势能与热能的比值。研究发现，与仅考虑自由电子的情况相比，由于ASD模型中考虑了负能量电子分布，等离子体对电离能和光电离截面的屏蔽效应更强。ASD模型的当前结果与弱耦合等离子体中的经典德拜 - 休克尔（DH）模型显示出合理的一致性。然而，由于DH模型对等离子体 - 电子密度分布的近似处理，在中等耦合和强耦合等离子体中观察到这两个模型之间的电离能和截面存在显著偏差。在低光电子能量区域，由于屏蔽效应不同，ASD模型得到的截面形状共振峰位置与DH模型的显著不同。
