Eur. Phys. J. D 42, 73-77 (2007)
https://doi.org/10.1140/epjd/e2006-00273-1

Evaluation of the single ionisation transition amplitude using the CDW-EIS model within the framework of the impact-parameter method

¹ Department of Applied Physics, Faculty of Engineering, University of Miyazaki, Miyazaki, 889-2192, Japan
² Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), PO Box 51, 4001 Debrecen, Hungary
³ Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, Avda E. Bustillo 9500, 8400 Bariloche, Argentina

Received: 20 July 2006
Revised: 18 October 2006
Published online: 15 December 2006

Abstract

The continuum distorted-wave model with an eikonal initial state for ionisation is discussed within the framework of the impact-parameter method. Particular attention is paid to the surface term, which describes the transition by a distorting potential, and which has been omitted in all of the previous calculations performed using the model. However, this term is included in the transition amplitude in a recent application of the model based upon a quantum-mechanical treatment. The present study, in which the surface term is evaluated within the impact-parameter method, shows that this term does not contribute to the transition amplitude. In describing the electron-ejection mechanism for a p^±–H collision, the cross-sections evaluated using the impact-parameter model show numerical agreement with those determined in the quantum-mechanical version. This agreement indicates that the contribution of the surface term calculated in the wave treatment is negligible over the region in which the impact-parameter model is valid.