全能域电子与中性原子和低离化度离子碰撞激发截面及电子关联作用研究

项目名称： 全能域电子与中性原子和低离化度离子碰撞激发截面及电子关联作用研究

项目编号： No.11474031

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 韩小英

作者单位： 北京应用物理与计算数学研究所

项目金额： 90万元

中文摘要： 电子与原子（离子）碰撞激发过程的理论研究不仅具有重要的基础科学意义，而且在实验室和天体等离子体研究领域中具有重要的应用价值。由于等离子体中自由电子的能量分布在一个很宽广的范围，因此模拟和诊断等离子体需要从低能到高能整个能域的电子碰撞激发截面。本项目提出一个有效计算中性原子和低离化度离子的全能域电子碰撞激发截面的方案。本方案主要基于两种计算方法：分波法（低能区有效）和一阶玻恩近似方法（高能区有效）。中能区的激发截面则通过两种方法计算的分波截面得到。根据该方案，我们将发展相应的计算程序，并以Ne、Na等原子和其低离化度离子为例，展示方案的可行性和有效性。此外，我们将研究电子关联作用对该动力学过程的影响并提出一个有效消除赝共振的方案。本项目的研究不仅能加深对电子关联作用的认识，提高我们处理全能域电子碰撞激发过程的能力，而且计算结果将为天文研究提供所需的原子参数。

中文关键词： 电子碰撞激发截面；赝共振；分波法；一阶玻恩近似；电子关联

英文摘要： The study of electron collision excitation cross sections of an atom (ion) not only has important fundamental scientific value but also has practical importance in laboratory and astrophysical plasma research fields. Since the energy of the free electrons prevails a wide energy range, the simulation and diagnosis of the plasma needs the electron collision excitation cross sections of the atom (ion) in a whole energy range.This project will present an effect scheme to deal with the electron collision excitation process of an atom and lowly charged ion from the low incident energy to the high incident energy. There are two calculation methods used in this scheme: one is the partial wave method (applicable in the low-energy range) and the other is the first Born approximation (applicable in the high-energy range). The cross sections in the middle-energy range can be obtained based on the partial wave cross sections calculated by the two methods. According to the scheme, a set of codes will be developed. The feasibility and validity of the scheme will be illustrated by the examples of Ne,Na atom and their lowly charged ions. In addition, we will study the influence of the electron correlations on the collision process and present a strategy to eliminate the pseudoresonance in the R-matrix calculations. This project will make a deeper insight of the electron correlations and upgrade our ability to deal with the electron collision process as well as provide the necessary atomic parameters for astrophysical research.

英文关键词： electron collision excitation cross section;pseudoresonance;partial wave method;first Born approximation;electron correlation