K- andL-shell vacancy sharing between light projectiles and argon targets

Auger electron measurements were made to determine vacancy-production cross sections in collisions of various light projectiles with argon atoms for projectile energies ranging from 30 to 600 keV. Ratios of projectile $K$-shell to argon $L$-shell vacancies were determined for comparison with theoretical models. Several different ab initio molecular-orbital and total-energy calculations were performed and compared for use in calculating theoretical sharing ratios. Total-energy differences for molecular states with inner-shell vacancies were compared with molecular-orbital energy differences. The experimental ratios are only moderately well reproduced using current theoretical models with model parameters derived from the ab initio calculations.