Theoretical Study of Dynamical Processes in Highly Excited Molecules up to Double Ionization

我对高激发电子态的动态过程进行了理论研究，这些电子态的能量接近并高于第一电离势。主要研究的过程是解离重组（DR）和解离激发（DE）。其机制与其他过程相同，即电子撞击引起的旋转和振动激发。在这些过程中，电子和核运动之间存在强量子力学和高密度耦合。我开发了一些理论方法来表示这些复杂的过程，并通过数值计算阐明了这些过程的机制和现有方法的可用性。所研究的分子体系是H_2和HeH及其同位素，这是典型的受不同机制控制的两个体系。在DR if HD^ e中，其机制随碰撞能量的变化而变化。在较低能量下，我研究了包括旋转运动在内的过程，并精确估计了非绝热电子共振散射的影响。该结果首次代表了实验结构。在较高能量下，我通过将离散解离基函数引入通常的多通道量子缺陷理论来计算 DR 和 DE 截面。除了获得原子数据外，我还展示了 DR 和 DE 之间的共同机制。本研究表明了 HeH^ 的 DR 截面大的原因，其中不存在解离共振态。解离态之间的非绝热耦合可以通过引入闭合解离通道的概念来表示。本计算首次再现了实验光谱和同位素依赖性。

I have done theoretical studies on the dynamic processes relevant to the highly excited electronic states, of which energies are near and higher than the 1st ionization potential. The processes mainly studied are dissociative recombination (DR) and dissociative excitation (DE). of which mechanism is common to the other processes as rotational and vibrational excitation by electron impact. There is strong, quantum mechanical, and high density coupling between electronic and nuclear motion in those processes. I developed some theoretical methods to represent those complex processes, and made clear the mechanism of those processes and availability of the present methods by numerical calculation. The studied molecular systems are H_2 and HeH and those isotopes, which are typical two systems controlled by quite different mechanisms.In the DR if HD^+ + e, its mechanism changes with collision energy. At the lower energy, I investigated the process including the rotational motion and estimating precisely the effect of nonadiabatic electronic resonance scattering. This result the first to represent the experimental structures. At the higher energy, I calculated the DR and DE cross sections by introducing the discretized dissociative basis functions to the usual multichannel quantum defect theory. Besides obtaining the atomic data, I show the common mechanism between the DR and DE.The present study shows the reason of large cross section in the DR of HeH^+, where the dissociative resonance state is absent. The nonadiabatic coupling between the dissociative states could be represented by introducing the idea of closed dissociative channel. The present calculation reproduce the experimental spectrum and isotope dependence for the first time.