ELECTRON-ENERGY SPECTRA OF H- DOUBLY-EXCITED STATES RESULTING FROM COLLISIONS OF H- WITH HE

Electron-energy spectra for H- doubly excited states resulting from co llisions of H- with He are rigorously calculated within a semiclassica l molecular representation by including couplings between doubly excit ed states and continuum states and their interference with direct-deta chment processes. An energy sampling procedure, based on the Gauss qua dratures, is used to discretize continuum states. The present theoreti cal result clarifies mechanisms of excitation to doubly excited states , quantitatively reproduces the experimental spectra first observed by Risley and Geballe in 1974, separates the contributions from each of three doubly excited states, and identifies the cause of the interfere nce between channels arising from double-electron excitation and direc t detachment with simultaneous excitation.