Atomic Collision Processes in Dense Plasmas

In the present work a detailed investigation of various atomic collision processes important to the determination of the structure and evolution of dense plasmas is presented. In volume 1 a study of general collisional processes in dense plasmas is given, while in volume 2 specific mechanisms by which energy is transferred among the constituents of a dense plasma is studied. Specifically, in chapter I, attention will be focused upon ion-ion recombination processes in dense plasmas, which involves the full set of multicomponent BBGKY equations appropriate for a three component gas composed of positive and negative ions, and neutral particles. This yields a set of coupled Boltzmann-type equations to be solved for the full phase-space evolution of the plasma, valid for arbitrary neutral gas density. In the limit of low (neutral) gas densities the theory in chapter I naturally tends to the exact quasi-equilibrium treatment of ion-ion recombination of Bates and Moffett, and Bates and Flannery. It also provides a firm basis for developing a fully general theory of recombination in dense plasmas subject to external electromagnetic fields as well as for dense plasmas with arbitrary ion densities. In chapter II symmetric resonance charge transfer processes Rg('+) + Rg (--->) Rg + Rg('+) for Rg = Ne, Ar, Kr, and Xe are studied via a quantal phase shift analysis. Accurate ab-initio and density functional potentials for the Rg(,2)('+), dimer are to be used, with the effects of spin-orbit coupling included, in order to compute elastic, charge-transfer, diffusion, and viscosity cross sections in the thermal energy region. In chapters III, IV of volume 2 the electron-impact excitation of excited hydrogen and helium atoms, respectively, are studied via the multichannel eikonal theory (MET) of Flannery and McCann. The MET is modified to account, asymptotically, for the strong dipole couplings present between the excited states of hydrogen and helium, thereby allowing accurate computation of differential and integral cross sections and the relevant orientation and alignment parameters.