Single and double K-shell vacancy production in N7++Ticollisions

Non-perturbative classical models were applied in the study of K-shell vacancy production in N7+ and Ti collisions in the 4-26 MeV/u projectile energy range. Total cross sections for the single and double K-shell vacancy productions are calculated by means of a simple binary encounter model, classical trajectory Monte-Carlo methods within and beyond the independent electron approximation. The experimental and theoretical ratios of the double- to single-vacancy production yields have been compared. It is demonstrated that a simple model for accounting the final state electron-electron correlation in the double capture and the capture + ionization channels significantly improves the agreement between experiment and theory compared to the independent electron approximation. (C) 1999 Elsevier Science B.V. All rights reserved.