Variation of Ionization Mechanisms with q in theCollision of He2+ with Cq+

Abstract

The ionization process in the collisions of He2+ withCq+ (q = 0–5) is investigated by using thecontinuum-distorted-wave eikonal-initial-state approximation.Double-differential cross sections for 1s and 2s sub-shellsare obtained at the electron-ejected angle θ = 0° with theprojectile energy ranging from 30 keV/u to 10 MeV/u. Variation ofionization mechanisms with q in Cq+ is studied, and thedependences on the projectile energies and target sub-shells are alsodiscussed. It is found that in the whole energy range, the absolutevalues of soft collision (SC) and binary encounter (BE) peaks decreasewith increasing q. For the lower incident energies, the electroncapture to the projectile continuum (ECC) peak decrease with increasingq as well as SC and BE peaks. For the higher incident energies(>1 MeV/u), the absolute value of ECC peak increases with increasingq, so that the crossings of cross sections appear for Cq+ withdifferent q. This can be explained by the matching of velocitiesbetween the projectile and the electron initially bound to the target.