Sheng-Fang Lin

Impact-Ionization Processes in Fusion Plasmas

Starting from the relativistic equation of motion governing quantum collision processes in many-particle systems, we shall formulate the relativistic quantum collision theory in an ab initio manner. Quantum electrodynamic effects are however in corporated perturbatively. Because heavy projectiles or ultra-high incident energies are considered, the recoil of the target is also treated. Electron-impactionization of uraniumion U91+ and proton-impactionization of hydrogen will be given as examples.

Photoionization Processes of the Single-Ionized Boron

The relativistic calculations of the cross-section , the angular-distribution parameter , and spin-polarization parameters of photoelectrons using the multiconfiguration relativistic random-phase approximation theory for the photoionization of the ion are presented. Precise energies and widths of all five Rydberg series of doublyexcited states , , , , and are determined. Our predictions are in very close agreement with experiments and are consistent with other calculations.

Photoionization of Be, B+, C2+, N3+, O4+, and F5+ in the MCRRPA theory

The multiconfiguration relativistic random-phase approximation theory is applied to the valence-shell photoionization along the Be isoelectronic sequence. Photoionization cross sections between (1s22s)2S1/2 and (1s22p)2P°1/2 ionization thresholds are calculated. There are five Rydberg series of doubly excited states that manifest themselves as autoionization resonances in the photoionization cross section. A comparative study of Be, B+, C2+, N3+, O4+, and F5+ is presented.