Theoretical research in physics of highly ionized atoms. Final report, March 1, 1975--June 30, 1976

Results of a preliminary study of the use of a model potential approach to the calculation of energy levels and radiative transition probabilities for highly ionized heavy atoms are reported. The calculations were carried out for eight ions in the sodium isoelectronic sequence from Mg II through W LXIV. The technique used involved the solution of the Dirac equation for the single outer valence electron, with a model central potential containing two disposable parameters affecting the potential in the region of the atomic core. The effect of core polarization was incorporated in the model potential. The parameters in the model potential were chosen by an initial solution of the nonrelativistic Schroedinger equation for the single outer valence electron, with the requirement that calculated ionization energies reproduce the results of the best available nonrelativistic calculations. Comparison of results for nonrelativistic radiative transition probabilities provides the first check on the technique. Solutions of the Dirac equation are then compared with the results of other relativistic calculations and experimental measurements. The results, for both energy levels and radiative transition probabilities, are encouraging, and suggest that the wave functions obtained will be quite satisfactory for subsequent calculations of electron impact excitation of these ions