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

IGARASHI, A.; GULYÁS, L.; FAINSTEIN, P. D.

EUROPEAN JOURNAL OF PHYSICS

IOP PUBLISHING LTD

Año: 2007 vol. 42 p. 73 - 73

0143-0807

The continuum distorted-wave model with an eikonal initial state forionisation is discussed within the framework of the impact-parametermethod. Particular attention is paid to the surface term, whichdescribes the transition by a distorting potential, and which has beenomitted in all of the previous calculations performed using the model.However, this term is included in the transition amplitude in a recentapplication of the model based upon a quantum-mechanical treatment. Thepresent study, in which the surface term is evaluated within theimpact-parameter method, shows that this term does not contribute to thetransition amplitude. In describing the electron-ejection mechanism fora p±-H collision, the cross-sections evaluated usingthe impact-parameter model show numerical agreement with thosedetermined in the quantum-mechanical version. This agreement indicatesthat the contribution of the surface term calculated in the wavetreatment is negligible over the region in which the impact-parametermodel is valid.