HE PHOTOIONIZATION TO THE DOUBLY EXCITED (2PND) AND (SP,2N-)P-1(0) SERIES

We present an application of a configuration-interaction method for the continuum spectrum to He photoionization from the ground state to the doubly excited (2pnd) and (sp,2n-) P-1(0) series, using a finite L2-basis set constructed from a nearly complete set of spline-based one-particle hydrogenic orbitals. Our calculated resonance structures are in good agreement with the recent high-resolution synchrotron-radiation spectra [M. Domke, G. Remmers, and G. Kaindl, Phys. Rev. Lett. 69, 1171 (1992)]. Our calculated widths, resonance energies, and peak photoionization cross sections are also in close agreement with the most accurate existing theoretical results.