Ions and electrons from the solar wind plasma, a local pick-up ion plasma or a plasma trapped in a planetary magnetosphere can impinge on an atmosphere. This can cause heating of the thermo- sphere and loss of atmosphere. To describe this quantitatively elastic and inelastic collision cross sections are needed. Since in many cases these are not measured we carry out semi-classical or classical molecular dynamics calculations to the required cross sections.
Johnson, R. E., and Strobel, D. F., "Charge Exchange in the Io Torus and Exosphere," J. Geophys. Res., 87 (1982), p. 385.
McGrath, M. A., and Johnson, R. E., "Charge Exchange Cross Sections for the Io's Plasma Torus," J. Geophys. Res. 94 (1989) p. 2677-2683.
Johnson, R.E. "Formation of Na-containing Molecular Ions at Io" Icarus 111 (1994) p.65-72.
Luna, H., M. Michael, M.B. Shah, R.E. Johnson, C.J. Latimer, and J.W. McConkey, "Dissociation of N2 in capture and ionization collisions with fast H+ and N+ ions and modeling of positive ion formation in the Titan atmosphere" JGR 108, NO E4, 5033, doi:10.1029/2002JE001950 (2003). [pdf]
Tully, C. and R.E.Johnson, "Low Energy Collisions Between Ground State Oxygen Atoms", Planet & Space Sci. 49(6) (2001) 533-537.
Tully, C. and R.E.Johnson, "Semiclassical calculation of collisional dissociation cross section for N+N2" J. Chem. Phys. 117 (2002) 6556-6561. [pdf]
Tully, C., R.E. Johnson, "Erratum : 'Semiclassical calculation of collisional dissociation cross section for N+N2' [ J. Chem. Phys. 117, 6556 (2002)]", J. Chem. Phys. 119, 10452-10453 (2003). [pdf]