SIMPLE RELATIVISTIC CORRECTION OF THE SCALING PARAMETER FOR K-SHELL COULOMB IONIZATION

A simple modification of the scaling parameter xi for K-shell Coulomb ionisation, approximately accounting for electronic relativistic effects, is derived for low projectile velocities, PWBA calculations, using a simple parametrisation which includes this correction together with similar corrections for binding and nuclear Coulomb repulsion effects, are in very good agreement up to xi approximately=0.55 with a large number of experimental proton ionisation cross sections, spread over six orders of magnitude. Apart from the heaviest elements, similar SCA calculations overestimate the data by a few per cent.