Collision Density and Chemical Kinetics of Energetic Atoms. III

The gas-phase bimolecular reaction H + D2→HD + D of energetic hydrogen atoms scavenged by molecular iodine and moderated by argon at 1000°K is studied by stochastic and analytical methods. A differential form of the Boltzmann equation for this system is discussed and coefficients of the differential equation are derived. Solutions for the collision density obtained from the differential equation and from an independent stochastic computer program are found to be in satisfactory agreement. The effect on the collision density of changing the moderator species from argon to helium is investigated and rate constants for both the argon- and helium-moderated systems are given.