Study of structure of excitation cross-section of resonance level in helium ions by electron-impact

Excitation of the He2 2p-level is optically investigated using the technique of crossing modulated ion and electron beams. The structure of excitation cross section resulting from the resonance capture of electrons by ions with the formation of autoionization states is observed in the 43-52 eV energy range. Relative contribution to populating the He2 2p-level from the autoionization states does not exceed 20% of population due to the direct process. Experimental results well agree with calculations conducted using the diagonalization method