电子-若干复杂分子碰撞总电离截面研究

Ionization process of electron collision by molecules is worth studying. The reasons are of two folds. One is that such investigations can explore the detailed molecular structure. The other is that the work can be used to validate the basic physical principles and experimental and theoretical methods. Studies on the ionization process of electron collision by molecules are a both challenging and innovating project.. The purposes of the present project include three aspects. First, we will modify the additivity rule (AR) by taking into consideration that the contributions of the geometric shielding effect vary with the energy of the incident electrons, the target's molecular structure dimension, polarizability and the atomic and electronic numbers of the molecule. Using the modified AR approach, total ionization cross sections for electron collision by polyatomic molecules will be calculated over the energy range from several ten to several thousands eV. A complete set of theoretical total ionization cross sections will be settled down and the physical insight into the modified AR approach will be gained. Second, the total ionization cross sections for electron collision by complex polyatomic molecules in particular by interstellar and biologic complex molecules, will be calculated over the intermediate- and high- energy range, by which the total ionization cross sections for electron collision can not be accurately determined by other theoretical methods. At the same time, the modified AR approach will be extended in order to obtain total ionization cross sections for electron collision by molecular clusters. And finally, the relationship between the total ionization cross sections for electron-molecule collision and the inherent parameters of polyatomic molecules. The semi-empirical formula of the total ionization cross sections for electron-molecule collision will be explored, and thus the total ionization cross sections will be calculated by the semi-empirical formula. The detailed insight into the ionization mechanism of electron-molecule collision will be obtained.

对电子-分子碰撞电离过程进行研究，不仅是揭示分子结构的有力手段和检验基本物理理论及研究方法的重要途径，而且还具有重要的应用价值，是富有挑战性和创新性的研究课题。.本项目研究内容包括三方面，一是在考虑分子内原子间的屏蔽效应随电子入射能量和分子结构、尺寸、极化率及所含有的原子和电子总数等变化的基础上对可加性规则进行修正，并利用修正后的方法计算数十到数千电子伏的中高能电子与多原子分子碰撞的总电离截面，获得一套较完整的理论数据并诠释修正方法的物理本质；二是提供实验尚未给出、但其它理论又难以准确计算的中高能电子与复杂大分子、尤其是与星际复杂分子和生物大分子的碰撞总电离截面，并将计算方法推广到电子与团簇分子碰撞总电离截面的研究中；三是研究电子-分子碰撞总电离截面与入射电子能量及分子本身所固有参数间的关系，探索总电离截面的变化规律并找出其准经验计算公式，以获得对电子-分子碰撞电离机制与规律较深刻的认识。

对电子-分子碰撞电离过程进行研究，不仅是揭示分子结构的有力手段和检验基本物理理论及研究方法的重要途径，而且还具有重要的应用价值，是富有挑战性和创新性的研究课题。.本项目的研究内容包括三方面，一是在考虑分子内原子间的屏蔽效应随电子入射能量和分子结构、尺寸、极化率及所含有的原子和电子总数等变化的基础上对可加性规则进行修正，并利用修正后的方法计算数十到数千电子伏的中高能电子与多原子分子碰撞的总电离截面，获得了一套较完整的理论数据并诠释了修正方法的物理本质；二是提供了实验尚未给出、但其它理论又难以准确计算的中高能电子与复杂大分子、尤其是与星际复杂分子和生物大分子的碰撞总电离截面；三是研究了电子-分子碰撞总电离截面与入射电子能量及分子本身所固有参数间的关系，探索初了总电离截面的变化规律并找出其准经验计算公式，并获得了对电子-分子碰撞电离机制与规律较深刻的认识。