Vibrational distribution excitation regimes

Non-Equilibrium Vibrational Distribution Functions Regime of Weak Excitation... 

This plateau-Boltzmann transitional energy corresponds to the equahty of probabilities of the VT relaxation and the resonant W exchange. The vibrational distribution function in the regime of strong excitation in non-thermal plasma is illustrated in Fig. 3-7. 

Figure 3-7. Non-equilibrium vibrational energy distribution functions in diatomie molecular gases strong and intermediate excitation regimes.

Vibrational distribution similar to that presented in Fig. 3-7 also takes place in the regime of intermediate excitation, which occurs when < Syy, but the Treanor effect is... 

The population of vibrationally excited states at the Treanor minimum E = Exr) is large in this regime, and the non-linear resonant W exchange dominates and provides a plateau at > i Tr even though < 5yy. At low levels E < E-y ), the linear non-resonant W exchange dominates over the non-linear one. It does not change the vibrational distribution function, however, because both non-resonant and resonant components of the W exchange result in the same Treanor distribution at < Ej. ... 

Figure 3-16. Influence of a chemical reactionon the vibrational distribution function in the weak excitation regime of non-equilibrium plasma Ty To).

Hyperbolic Plateau Distribution of Vibrationally Excited Molecules. Derive a relationship between the hyperbolic plateau coefficient C (3-133, 3-134) for the vibrational energy distribution function and the ionization degree in non-thermal plasma (Ke/ o)- Take into account that, in the strong vibrational excitation regime, the excitation of lower vibrational levels by electron impact is balanced by resonant non-linear VV exchange between higher vibrationally excited molecules. 

Collision-induced dissociation is a particular case of unimolecular reaction, such that in the statistical limit the unimolecular RRKM theory can be applied [11]. This theory tmderlines that the micro canoiucal distribution is preserved along the reaction path, and thus the IVR regime is supposedly achieved within the characteristic reaction time. As pointed out by Schag and Levin some years ago, the unimolecular dissociation of large molecules reflects bottlenecks to intramolecular vibrational energy distribution and the available phase space is too large to allow dissociation from a uniform distribution of the excitation [12]. As we have... 

Fig. 4 Snapshots of the probability distribution evolution for two CO molecules on a copper(lOO) surface subject to non-adiabatic coupling. The dynamics is initiated with two quanta of vibrational excitation in one of the CO molecules, here the qi mode. The labels full and fact, refer to the choice of vibrational basis to represent the reduced density matrix in eqn (19). The left panels show the system in the absence of intermode coupling and the strong intermode coupling regime is depicted in the right panels. Reproduced with permission from ref. 97.

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