A Theoretical Study For The Rotation Excitation Cross Section Of The Diatomic Molecules With Atoms And The Resonance Structure In The Photoionization Of The Ion Ca～+

The interactions between atoms and molecules undertake a very important role in many physical processes and the investigation of rotation excitation cross sections of in the collisions of molecules with atons are an excellent method determining their interactions. Many theoretical and experimental researcher have done a lot of reseach work hi this field and got plenty of theoretical and experimental data. The total scattering cross sections(TCS), the differential cross sections(DCS), the partial wave cross sections(PCS) and the rotational excitation cross sections(RECS) for the collision of H2(D2,T2) with inertia gas atoms He, Ne, Ar, Kr, Xe have been calculated by using the close-coupling approximation method at relative kinetic energy of 0.05eV to 0.25eV , respectively. By analyzing the differentiae of the total cross sections(TCS), the differential cross sections(DCS), the partial wave cross sections(PCS), the change patterns of the cross sections and the influence on the cross sections because of the variations in the mass of systems and the relative kinetic energy of incoming atoms for symmetric isotopically substituted systems He,Ne, Ar, Kr,Xe-H2,D2, T2 have been obtained.In this paper, we use the Tang-Toennies potential model for the inertia gasatoms-H2 systems, the Murrell-Sorbie potential surface with five parameters for the molecules H2,D2, T2. For the inertia gas atoms-D2,T2 systems, we use the same potential surface with the inertia gas atoms-H2 systems.In part two of this paper, many-body perturbation theory has been used to calculate the resonance structure (3p-3d) into the photoionization (4s-kp) for ion Ca+. This resonance structure results from the interference between a photoionization process or a photoionization with excitation process and a resonant Auger process. The coupled equation method has been improved to calculate this interference by the summation of specific classes of diagrams of perturbation theory to infinite order. The resonance structure in the region of the 3p threshold is enhanced via a super-Coster-Kronig transition. The theoretical results are in good agreement with experiment.