Time-dependent nonthermal rate

Figure 2. Time (curve A) and Ta (curve B) dependent nonthermal rate coefficients for the + Hi reaction at 300°K ambient temperature...

Table IV. Properties of Time Dependent Nonthermal Reaction Rate Distributions at 300°K and 10°K Ambient Temperatures,...

Koura (l ) has investigated the possible formation of high temperature steady states in the nonthermal + Hg system using a Monte Carlo numerical procedure for solving the time dependent Boltzmann equation. Reactive cross section data reported from this laboratory were employed together with an energy dependent hard sphere model. Time dependent momentum relaxation, reaction rate and yield results were obtained for a variety of assumed initial hot atom momentum distributions. 

To the extent that K(t) is constant throu out a time interval that is comparable to then the correct time dependent rate expression can be replaced by an approximate quasi steady state analog. Even in the absence of a true steady state, certain features of an average rate coefficient formulation will continue to be applicable (23.25.27,51,32). This conclusion is insensitive to the present assumptions concerning nonreactive scattering. It would be strengthened by the inclusion of a more realistic representation of the energy dependent nonreactive cross section, since a relative reactivity increase would lead to ccmipression of the time and ranges sampled by nonthermal reaction. 

The nonthermal reaction rates exhibit significant time dependence variations associated with the presence of inert moderators. From Figs, 8 and 9 the addition of 99 mole ... 

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