Wavefunction effects in inner-shell ionisation of light atoms by protons

Abstract

An efficient computer code for calculating the impact parameter distribution of atomic ionisation probabilities caused by charge particle impact, has been developed. The program is based on the semiclassical approximation, and it allows the use of an arbitrary atomic central potential for deriving the one-electron orbitals that form the basis for the description of the atomic states. Extensive calculations are reported for proton induced K-shell ionisation in carbon and neon, covering energies in the range 0.1-10 MeV. Some calculations on proton-argon L-shell ionisation are also reported. Comparison between the results obtained using (screened) hydrogenic potentials and the recently reported energy optimised effective atomic central potentials demonstrates that wavefunction effects are generally important for inner-shell ionisation of light atoms. The agreement between theory and experiment in the K-shell case is improved for fast collisions upon using better wavefunctions.