Collision dynamics of the He 2+ +H͑1s͒ system imbedded in a Debye plasma is studied by the two-center atomic orbital close-coupling ͑AOCC͒ method in the energy range 5 -300 keV/ u. The atomic orbitals and electron binding energies of atomic states are calculated within Debye-Hückel approximation of the screened Coulomb potential and used in AOCC dynamics formalism to calculate the state-selective electron capture and excitation cross sections. The basis contained 174 orbitals centered on the target ͑all n Յ 6 discrete states and 117 quasicontinuum states͒ and 20 orbitals centered on the projectile ͑all n Յ 4 discrete states͒. It is demonstrated that the screening of Coulomb interactions in the system progressively reduces the number of available excitation and electron capture channels when the screening parameter increases. The screening of Coulomb interactions introduces changes also in the values of direct and exchange couplings, thus affecting the magnitude and energy behavior of the cross sections. The control of dynamics of collision processes in a Debye plasma by varying the plasma screening of Coulomb interactions in the collision system is discussed.

State-selective and total single-electron-capture cross sections in collisions of H + with the excited Li * (2p) atom have been investigated by using the full quantum-mechanical molecular orbital close-coupling (QMOCC) method in the energy range 0.001-3 keV/u and by the two-center atomic orbital close-coupling (TC-AOCC) method in the energy range 0.1-100 keV/u. The present results are also compared with data from other sources when available. It is found that the total and partial electron-capture cross sections are sensitive to the initial p-state charge cloud alignment, particularly in the low-energy region.

Synopsis Bremsstrahlung and Compton scattering are the important processes including the continuum electrons in the hot warm matters. The distribution of the continuum electrons is affected by the plasma screening, which will influence the cross sections of Bremsstrahlung and Compton scattering. In the present work we will investigate the plasma influence on these processes.