离子-分子碰撞电荷转移和解离过程中取向效应的理论研究

Charge transfer and dissociation in ion-molecule collisions are important processes in astrophysics and plasma physics. Many experiments on ion-molecule collisions have been performed with high resolusion. A growing number of experiments concentrate on the vibrational state selective cross sections and the alignment effect. However, the theoretical investigations on this topic are still very limit due to the multicenter and multielectron challenges. In this project, we will research on the ion-molecule collisions in the low energy region comprehensively. The molecular data of the collision systems will be calculated using the ab initio method. The electronic and vibrational state-selective and differential charge transfer cross sections will be investigated by the quantum-mechanical molecular-orbital close-coupling method. The collision induced dissociation cross sections will be given and the differential angular distribution of the dissociation fragments will be investigated. The theoretical results will be compared with the experimental measurements based on the 320 kV platform for multi-discipline research with highly charged ions in the Institute of Modern Physics. The alignment effect on charge transfer and dissociation will be studied and the physical mechanism will be analyzed. The cross section data obtained in this project will be applied in the magnetic confinement fusion plasma physics.

离子与分子碰撞的电荷转移和解离过程在天体物理和等离子体物理中有重要应用背景。目前关于离子-分子碰撞的实验研究很多，正向着高精度的方向发展，越来越多的实验开展了对振动分辨的态选择截面和分子取向效应的测量工作。而由于涉及多体、多中心问题，理论上关于离子-分子碰撞的研究很少，特别是低能区的碰撞过程，还存在大量富有挑战性的科学问题。本项目中我们将对低能区的离子-分子碰撞过程进行全面深入的研究。利用从头算方法计算碰撞体系的分子结构；利用全量子的分子轨道强耦合方法计算电荷转移过程的电子态和振动态选择截面和微分截面，计算碰撞诱导解离截面和解离碎片角分布；结合近代物理研究所320 kV高电荷态离子综合研究平台的相关实验测量，研究分子取向对碰撞截面的影响，并分析其中的动力学机制。同时我们的计算将为目前磁约束聚变实验室等离子体物理研究提供一些急需的截面数据。

离子与原子分子碰撞的电荷转移和解离过程在天体物理和等离子体物理中有重要应用背景。目前关于离子与原子分子碰撞过程的实验工作开展了很多，而理论工作主要集中在对离子-原子碰撞的研究。由于涉及到多体、多中心问题，对低能区离子-分子碰撞的理论研究很少。本项目中我们对离子-分子的碰撞的电荷转移和解离过程进行了研究，通过修改MRDCI量化程序计算相关体系的势能曲线和耦合矩阵元，利用全量子的分子轨道强耦合方法计算碰撞截面，并研究了分子取向对碰撞截面的影响。此外，我们还研究了一些在等离子体物理中有重要应用的离子-原子碰撞体系，计算了这些过程的电子俘获截面，为磁约束聚变等离子体物理的相关应用提供了理论支持。