Calculations of atomic structures in the problems of interaction of heavy-ion beams with targets

The process of energy conversion in heavy-ion inertial confinement fusion is associated with the deceleration of heavy ions in a low-temperature plasma that is produced when the beam ionizes the target material. In order to calculate the deceleration of heavy ions in a target, it is necessary to determine the wave functions, energy levels, and oscillator strengths for atoms and for ions in different charge states. The models that have been developed thus far to calculate deceleration processes apply only to gas targets. In the present paper, a method is proposed that is based on the Hartree-Fock-Slater model and makes it possible to perform calculations for experiments with both low-density (gas) and high-density (solid) targets. The method applies to neutral atoms and also to ions in different charge states. Results are presented from calculations carried out for nitrogen, oxygen, aluminum, and silicon atoms and are compared with the results obtained by other authors and with the experimental data. It is shown that, for high-density targets, the method proposed provides better agreement with experiments than do the models developed earlier.