Of Helium Doubly Excited State Of Generalized Oscillator Strength Density Theory

Helium, as the simplest and prototype neutral atom that exhibits the strong electron-electron correlation effects, has attracted considerable research interests for a long time. Due to the two electrons exist in the out region of the atomic core, doubly excited resonances are of special interests for strong bound-bound, bound-continuum and continuum -continuum interaction. Compared with the photoionization cross sections, the spectra of general oscillator strength density usually provide more information of the doubly excited resonance states.Based on R-matrix method, the energy levels of ground and singly excited states of helium are calculated. Within the framework of the first Bora approximation, and the wave functions calculated using R-matrix method, we developed the code to calculate the general oscillator strength densities of the 1P?doubly autoionization states of helium under the N=2 and N=3 threshold of He+. Our calculated results agree with the recent experimental measurements. The effects of the different target states to the calculated results, and the variance of the general oscillator strength density according to the increase of moment transfer, are discussed.