Photoionization from metastable (1s2s) 1Se and 3Se states of the He atom for energies between the N=2 and 3 thresholds of He+

摘要: Photoionization cross sections from the metastable state (1[ital s]2[ital s]) [sup 1][ital S[ital e]] of He atom for photon energies between He[sup +] ([ital N]=2) and N]=3) thresholds are calculated using hyperspherical close-coupling method. The spectra convoluted with an energy resolution 5.4 meV compared photoionization ground state. It is found that among four possible outgoing channels, 1[ital s][epsilon][ital p] channel, which dominant channel state, makes negligible contributions to total As a result, propensity rule derived ground-state no longer applies more series doubly excited states populated significant spectral intensity in 3][ital also analyzed.