K-shell excitation probabilities in 32 MeV S on Ar collisions

Abstract
In collisions of 32 MeV Sn+ on Ar, impact parameter dependent K-shell excitation probabilities PK(b) have been determined for n=5, 11, and absolute K-shell excitation cross sections sigma K for n=5-13. A comparison between PK(b) and the 2p pi -2p sigma rotational coupling model clearly shows the main contribution to the total K-shell excitation cross section sigma K to be due to rotational coupling. This is also true for S5+ where no static L vacancies are present prior to the collision. The increase of sigma K with projectile charge state n+ (for 5K, the contribution of direct 2p sigma excitation is found to be important.