We have used an R-matrix close coupling algorithm to calculate capture, ionization and excitation cross sections for 0.5 to 8.0 MeV K+ incident on argon and neon. These energies, ions and gasses are relevant to the High Current Experiment (HCX) at Lawrence Berkeley National Laboratory, where impact ionization of background gasses is a main source of contaminant electrons. The Rmatrix close coupling algorithm is a semi-classical algorithm that uses quantum mechanics to describe the particle

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... actions and classical mechanics to describe the nuclei trajectories. We find for argon, ionization and capture cross sections are roughly equal and on the order of a few 10 -17 cm 2 . For neon, we find the cross section for ionization is a few 10 -16 cm 2 , while the cross section for capture is a few 10 -17 cm 2 .