Steady state hot atom kinetic theory

The enhanced velocities possessed by hot atoms dramatically shorten the time scales associated with nonthermal collisions. Approximate recoil F mean thermalization times, , corresponding to simulated MNR conditions have been calculated (4) using the local equilibrium steady-state hot atom kinetic theory (21,22,41). The values can be compared with the mean reactive lifetimes for thermal Reaction 5, , obtained from absolute and MNR sample composition data. At readily accessible moderator concentrations, the were shown to be tenfold or more larger than the , even for very reactive R species. A calculated [/] ratio of 160 was obtained for C2H6 present at 5.0 X lO" mol fraction in C2F6, showing that hot atom moderation is effectively completed prior to the onset of Reaction 5 in this system. 

This more conventional use of the term steady state, which simply connotes time-independence for N(E), is fundamentally different from the dynamical definition that arises in the steady state hot atom kinetic theory (i5.ll)-). 

In order to elucidate the dynamical features of a hot atom reaction, the microscopic time dependent collision cascade must be modeled. Provided that the required reactive and nonreactive cross section data are available, this can be accomplished using the steady state hot atom kinetic theory ( ). This section contains a brief introduction to.the mathematical apparatus. 

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