Development of High-Resolution Flight-Time Analysis and Study of Low-Energy Charge Transfer Reaction by the Beam Guide Technique.

本项目发展了一种新的飞行时间分析方法，并在&lt；Li^&gt；&lt；Li^&gt；和&lt；Na^&gt；分子靶与CO和&lt；H_2&gt；以及离子的质量分析中证明了该方法的有效性。同时，利用八极离子束导引技术，在0.1-1000 eV的碰撞能区测量了许多新的电荷转移反应和离子分子反应的截面数据。在&lt；Ar^(2)&gt；，&lt；Kr^(2)&gt；，&lt；Ar^(3)&gt；和&lt；Kr^(3)&gt；与母体气体的碰撞中，发现对称共振多电荷转移过程特别重要，其截面在低能时变得比其他过程的截面大。在&lt；Ne^(2)&gt；，&lt；Ar^(2)&gt；，&lt；Kr^(2)&gt；与He的碰撞中，测得的单电子俘获截面几乎都符合曲线交叉模型，并可用Landau Zener计算结果进行定性解释。在&lt；H^&gt；、&lt；H(2^)&gt；和&lt；H(3^)&gt；与&lt；H_2&gt；的离子-分子反应中，区分了18个反应通道，并求出了它们的截面。在&lt；Ne^(2)&gt；-lt；H_2&gt；和&lt；N_2&gt；中，获得了单电子和双电子俘获截面。此外，在&lt；Ne^(2)&gt；-&lt；N_2&gt；中，通过对&lt；N_2&gt；乘积的高分辨平动能分析表明，截面不仅由Franck-Condon因子表征，而且电荷转移几率对交叉半径敏感，并且发生了内壳价电子的俘获。

In this project, a new method of the flight-time analysis was developed by means of the tandem ion beam guide and its effectual performance was proved in the high resolution translational energy analysis of scattered ions in collisions of <Li^+> and <Na^+> with molecular targets of CO and <H_2> and also in the mass analysis of ions.In parallel, many new cross section data of the charge transfer reactions and the ion molecule reactions have been measured in collision energy region of 0.1-1000 eV by use of the octo-pole ion beam guide (OPIG) technique. In collisions of <Ar^(2+)> , <Kr^(2+)> , <Ar^(3+)> and <Kr^(3+)> with their parent gases, it is found the facts that the symmetric resonant multiple-charge transfer processes are especially important and their cross sections become larger than those of other processes at low energy. In collisions of <Ne^(2+)> , <Ar^(2+)> , <Kr^(2+)> with He, almost of one-electron capture cross sections measured are found to be according to the curve crossing modele and can be explained qualitatively by the results of Landau Zener calculations. In ion-molecule reactions of <H^+> , <H(_2^+)> and <H(_3^+)> with <H_2> , the eighteen reaction channels are distinguished and their cross sections are obtained. In <Ne^(2+)> - <H_2> and <N_2> , one- and two- electron capture cross sections are obtained. Also, in <Ne^(2+)> - <N_2> , it is cleared by aid of high resolution translational energy analysis of <Ne^+> product that the cross section is characterized by not only the Franck-Condon factor but also the charge transfer probability, which is sensitive to the crossing radius, and the electron capture of an inner shell valence electron of <N_2> takes place.