A Hard Sphere Model for Direct Three-Body Recombination of Heavy Ions

We describe a hard sphere model of direct three-body recombination of the Cs+ and Br- ions in the presence of neutral atoms Hg, Xe, Kr, or Ar as the third bodies. Calculations are carried out for the ion approach energy and the third body energy in the range from 1 to 10 eV under the assumption of non-central approach of the ions. The calculation results include the dependences of the total recombination probability on these energies as well as the opacity functions for two impact parameters and the dependences of the recombination probability on the angles determining the mutual orientation of the velocities of the reagents. The classification of the three-body collisions according to the sequences of pairwise encounters of the particles is considered. The most widespread mechanism of energy removal from the ionic pair is a single impact of the third body with the Br- ion.