On the semiclassical impulse approximation for electron capture in asymmetric ion-atom collisions

Abstract

A derivation of the impulse approximation for the capture of a target K-shell electron by a light projectile in ion-atom collisions is given in the framework of the semiclassical approximation. The impact-parameter dependence of the capture probability is calculated numerically without further approximations, and shows good agreement with recent experimental results for protons colliding with Ne and Ar. The validity of several peaking approximations and the relation to ionisation theories is briefly discussed.

Charge transfer in heavy-ion collisions at relativistic velocities

“…In the nonrelativistic case this peaking approximation was found to be quite good in the highvelocity limit [15]. Here it is even more justified because of the large projectile velocity, a large longitudinal momentum qz is required both to reduce the argument of Oy and to ensure momentum conservation, whereas the transverse components q• can be neglected.…”

Theoretical Models for Atomic Charge Transfer in Ion-Atom Collisions

“…29 ), BK (Belkic et al 29 ). Semiclassical theories: -IA (Jakubaßa-Amundsen and Amundsen 30 ), SPB (Alston 31 ), BK (Greenland 27 ).…”

Charge Transfer at Large Scattering Angles in Asymmetric Ion-Atom Collisions

“…The formalism developed in this section is a generalisation of the straight-line theory as described by JakubaBa-Amundsen and Amundsen [5] to an arbitrary nuclear trajectory. In a coordinate system centered at the target nucleus the Hamiltonian of the active electron is given by…”

“…Also for charge transfer in fast and asymmetric collisions, experiments have been performed which provided some insight in the dependence of the capture probability on impact paramter and collision energy [ 1-31. These measurements have mostly been concerned with very small projectile scattering angles, and could well be explained within the semiclassical impulse approximation [4,5]. Thereby the internuclear motion was approximated by a classical, straight-line trajectory.…”