Triple differential cross-section formulation for two-electron photoionization of the helium metastable (1s2s) 1,3 S states

M. Arifin (Department of Physics, Faculty of Mathematics and Natural Science Education, Indonesia University of Education Jl. Dr. Setiabudi No. 229 Bandung, West Java, Indonesia 40154)

Indonesian Journal of Physics (IJP)
Vol 14 No 4 (2003): IJP Vol. 14 No. 4, October 2003

The triple differential cross-section (TDCS) for two-electron photoionization on the helium metastable (1s2s)1,3S states has been formulated. The momentum space formulation of the close-coupling theory was employed to describe nonperturbatively the inelastic scattering in the final state of the atom. To represent the electron-electron correlation in the initial states the multiconfiguration Hartree-Fock method was used. A Laguerre basis (L2) was chosen to expand the target spaces both in the discrete and continuum states. The TDCS as well as the single and double photoionization cross-sections were obtained directly by solving the Lippmann-Schwinger integral equations.