The state-selective double-photoionization cross sections of the Ne III 2s22p4 [3P, 1D, 1S], 2s12p5 [3P, 1P] and 2s02p6 [1S] states in the exciting-photon energy region from 60 up to 200 eV are calculated with the use of V(N-1) and V(N-2) potentials. To our knowledge, the basis of wavefunctions obtained with the use of the V(N-2) potential is employed for the first time for the calculation of the total DPI cross section of a many-electron atom. The lowest-non-vanishing-order perturbation theory V(N-2) cross sections are compared with V(N-1) ones and with theoretical results of other authors. The obtained results show that the V(N-1) potential overestimates and the V(N-2) potential underestimates the experimental total DPI cross section of the L shell in Ne. The best agreement with experiment is achieved for the sum of the 2s12p5 and 2s02p6 state-selective V(N-2) velocity-form cross sections. The necessity of including the higher-order correlations, especially those responsible for singlet-triplet mixing of the final doubly excited states, is demonstrated and discussed.
|Number of pages||17|
|Journal||Journal of Physics B: Atomic, Molecular and Optical Physics|
|Publication status||Published - 28 Nov 2000|
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics