Elastic processes involving vibrationally excited molecules in cold hydrogen plasmas

We describe here a comprehensive quantum mechanical study of elastic scattering of protons by vibrationally excited hydrogen molecules and of hydrogen atoms by vibrationally excited hydrogen molecular ions, in the range of collision energies from a fraction of an eV to 6 eV. The problem was solved within a treatment considering all inelastic processes between the vibrational states, including excitation, charge transfer and dissociation. This was realized by expanding the problem in vibrational bases of H 2 and H 2 + which, in addition to all bound states, contained a large number of discretized vibrational continuum states, and solving the resulting set of coupled channel equations. The sudden approximation was applied with regard to rotations of the target molecule, and particular attention has been paid to convergence of the elastic cross sections with the number of partial waves of the projectile. Important plasma transport related moments of the elastic scattering cross section, the momentum transfer and viscosity cross sections, are also reported here and compared with inelastic cross sections for various vibrationally excited states.