Projectile-Auger-electron spectra of C3+ following 12-MeV collisions with He targets.

Abstract

Major features of the projectile-Auger-electron spectrum in the 220--300-eV energy range that are observed following 1-MeV/u collisions of Li-like carbon ions with helium target atoms are shown to be composites of closely spaced Auger lines that result from autoionizing (AI) transitions of excited ${\mathrm{C}}^{3+}$ configurations formed during the collision. From calculations of Auger-electron energies and Auger yields, a simulation of the Auger-electron spectrum is constructed and it is shown that a superposition of AI decays from LS-coupled doublets of the doubly excited ${\mathrm{C}}^{3+}$ 1s2snl configurations with n=2,3,4,...,\ensuremath{\infty}, reproduces most of the observed structure. Remarks are made concerning relative intensities of the Auger peaks with respect to excitation and population probabilities, particularly in the case of the two doublet terms of the 1s2s2p configuration. An Auger peak of \ensuremath{\approxeq}265.0 eV in the projectile frame that could not be accounted for in the 1s2snl series is attributed to a possible two-electron process in which one of the projectile electrons is ionized and another is excited.