Autoionization of Nq+ (q = 1-3) Rydberg states produced in high-energy collisions with He

Energy spectra of electrons ejected through autoionization decay of high-Rydberg states in high-energy collisions of Nq+ (q = 1-3) with He have been measured with high-resolution by using zero-degree electron spectroscopy. Several series of autoionizing lines were observed, corresponding to decays from N3+ 1s22p(2P)nl Rydberg states produced in N3+ + He collisions, from N2+ 1s22s2p(3P)nl Rydberg states produced in N2+ + He and from N+ 1s22s2p2(4P)nl Rydberg states produced in N+ + He, respectively. Angular momentum distributions for the first or second peak of three series of Coster-Kronig electron transitions for Nq+ (q = 1-3) projectiles are also discussed, where the highly excited states are formed by electron excitation.