We report the first experimental study of the angular momentum states populated by double-capture collisions of multiply charged ions. High-resolution spectra of L-Coster-Kronig electrons originating from ${\mathrm{O}}^{4+}$ 1$s^2$2pnl (n=6,7) states produced in 30–105-kev ${\mathrm{O}}^{6+}$+He collisions were obtained. Analysis of the observed spectra, performed with use of Hartree-Fock transition energies, indicates population of high–angular-momentum states. A classical-model calculation suggests that the correlated transitions producing the 1$s^2$2pnl autoionizing states involve both energy and angular momentum exchange between the two transferred electrons.

• Received 21 December 1987

DOI:https://doi.org/10.1103/PhysRevLett.60.1821