Electron-impact excitation and ionization of

Abstract

We present results from R-matrix with pseudo-states (RMPS) and convergent close-coupling (CCC) calculations for electron-impact excitation from and direct ionization of the ground state of the ion. Comparison of the CCC and RMPS results with those from first-order distorted-wave calculations as well as simpler close-coupling calculations, with only physical discrete target states in the expansion, indicate the importance of accounting for target continuum effects - even for this doubly ionized target. These conclusions are important for evaluating the reliability of the atomic data currently used for this collision system in various applications.