Classical Treatment of Aq+ + H Collisions

Abstract

One-electron collisions systems A q+ + H collisions are studied within CTMC model and compared with available experiments and quantum calculations. A large part of the chapter is devoted to H + + H collisions, which is a decisive test to validate classical calculations. Total cross sections, as well as partial and differential cross sections, are discussed. Then, A q+ + H collisions are examined. Interest and MotivationInelastic collisional processes involving atom or ion projectiles and atomic hydrogen H are of considerable interest, experimentally and theoretically. Since H atom constitute 95% of our universe and are present in many structures and experiments on earth, the understanding of processes and the determination of probabilities and total, partial, and differential cross sections is necessary. On a practical point of view, such reactions are relevant in tokamak fusion reactors, interstellar medium or solar wind.Since absolute total cross sections are very difficult to obtain experimentally with uncertainties smaller than 10%, typically, theories have to be included and improved to compare with experimental results, and to predict detailed quantities such as partial or multi-differential cross sections.Many theoretical approaches were developed using quantum mechanics and resolution of the Schrödinger equation. A q+ + H collisions are of great interest because there is only one active target electron, so that electron correlation in target wave functions, that may obscure details of the collision dynamics, has not to be taken into account.One problem is not the determination of the total cross sections. Measured total cross sections can be reproduced by theories with a high or satisfactory degree of accuracy for a broad range of kinematic conditions. Even if the Distorted-Wave Born approximation (DWBA) yields good agreement with experiment, even if models like the Continuum-Distorted-Wave Eikonal-Initial State (CDW-EIS) or Three-Body-Distorted Wave (3DW) approaches give a better agreement, it was recognized that total cross sections are not ideally suited to test theory? Indeed, in the integration of