Angle and Channel Dependence of Resonances ine-He Scattering near 60 eV

The He^- resonances at 57.1 and 58.2 eV in the electron scattering from He were studied as a function of angle in three inelastic channels corresponding to excitation of the (1s2s)³S, (1s2s)¹S, and (1s2p)¹P states of He. The line shapes of the resonances are found to vary with angle. The application of the Fano-Cooper formula, developed for the case of photon absorption, to resonances in inelastic electron scattering is discussed, along with a simple procedure for determining the line profile indices. The angular dependence of the ¹S, ³S, and ¹P excitations at 56.5 eV was also measured out to about 60^∘{}.