Energy loss spectra for single electron capture in Ar3+-He collisions

Differential cross-sections for ground to ground state single electron capture by 1250 eV Ar3+ ions in helium are reported and compared with curve-crossing theory. Three avoided crossings contribute to the single exit channel, and can be inferred from the scattering functions. Excited state energy loss spectra for this collision process are also reported at theta=00, 0.40. The presence of long lifetime excited states in the Ar3+ beam from the oscillating electron source is inferred. (author)