Near threshold photoionization of excited alkali atoms Ak(np) (Ak = Na, K, Rb, Cs; n = 3-6)
Fachbereich Physik, Universität Kaiserslautern, 67653 Kaiserslautern,
2 Rostov State University of Transport Communications, 344038 Rostov-on-Don, Russia
Revised: 14 October 1999
Published online: 15 April 2000
The effect of the polarization of the atomic core by the outer electron on near threshold photoionization of excited alkali atoms Ak(np) (Ak = Na-Cs; ) is investigated. Partial and total cross-sections for photo-ionization of the np-electron were computed utilizing the configuration interaction technique with Pauli-Fock atomic orbitals (CIPF) and including the long range core polarization potential (CP). To calculate the core polarization potential the variational principle is applied. Comparison with previous theoretical results and with available experimental data is made for the total cross-section σ, for the electron angular distribution parameter β, for the ratio of the reduced electric dipole matrix elements and for the phase shift difference , associated with the d-wave and s-wave continua, respectively. In the comparison, new experimental results for σ, ν, and Δ, measured for laser-excited, polarized 39K() atoms, have been included.
PACS: 32.80.Fb – Photoionization of atoms and ions / 33.60.-q – Photoelectron spectra / 31.50.+w – Excited states
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000