Vibrational to translational energy transfer

Vibrational to Translational Energy Transfer Experimental Results... 

Direct reaction (6-59) consumes vibrational energy of molecular nitrogen, whereas the reverse reaction consumes translational energy. For this reason the pair of two-temperature quasiequilibrium reactions (6-59), similarly to VT relaxation, leads also to intensive energy transfer from vibrational to translational degrees of freedom. Compare the rates of vibrational to translational energy transfer in these two mechanisms at conventional conditions of plasma-chemical NO synthesis. 

The rate of vibrational to translational energy transfer between a colliding atom and a molecule becomes more efficient with increase of their relative translational energies. Note the contrast with the collision efficiency factor used in the rate constant (5.31), that increases when the temperature is lowered. The rate constant k has a much stronger temperature dependence than the rate of energy transfer. 

E.E.Nikitin and S.YaUmanski, Vibrational to translational vs vibronic to translational energy transfer in molecular collisions. Comm. At. Mol. Phys. 3, 195 (1972)... 

A recent study of the vibrational-to-vibrational (V-V) energy transfer between highly-excited oxygen molecules and ozone combines laser-flash photolysis and chemical activation with detection by time-resolved LIF [ ]. Partial laser-flash photolysis at 532 mn of pure ozone in the Chappuis band produces translationally-... 

The photofragmentation that occurs as a consequence of absorption of a photon is frequently viewed as a "half-collision" process (16)- The photon absorption prepares the molecule in assorted rovibrational states of an excited electronic pes and is followed by the half-collision event in which translational, vibrational, and rotational energy transfer may occur. It is the prediction of the corresponding product energy distributions and their correlation to features of the excited pes that is a major goal of theoretical efforts. In this section we summarize some of the quantum dynamical approaches that have been developed for polyatomic photodissociation. For ease of presentation we limit consideration to triatomic molecules and, further, follow in part the presentation of Heather and Light (17). 

If both A and B are polyatomic relaxing gases, there will also be two collision processes, corresponding to (1) and (2), for vibration-translation energy transfer from B in homomolecular and heteromolecular collisions. In addition there can be a vibration-vibration transfer between A and B, making five transfer processes in all... 

Rotational quanta are much smaller than vibrational quanta, and rotational energy is therefore much more easily degraded to translational energy. For most molecules the collision number for rotation-translation transfer is less than 10, corresponding to relaxation times smaller than 10 9 sec at one atmosphere pressure. 

The first system we consider is the solute iodine in liquid and supercritical xenon (1). In this case there is clearly no IVR, and presumably the predominant pathway involves transfer of energy from the excited iodine vibration to translations of both the solute and solvent. We introduce a breathing sphere model of the solute, and with this model calculate the required classical time-correlation function analytically (2). Information about solute-solvent structure is obtained from integral equation theories. In this case the issue of the quantum correction factor is not really important because the iodine vibrational frequency is comparable to thermal energies and so the system is nearly classical. 

Data for vibrational-translational energy transfer are usually presented as a relaxation-time-pressure product pr, where r refers to the e-folding time... 

The electronic quenching process (eq. 13) may occur through an exoergic electronic-to-electronic (E-E) energy transfer, an electronic-to-vibrational (E-V) energy transfer, an electronic-to-rotation (E-R) transfer, an electronic-to-translation (E-T) transfer, or a chemical reaction. Studies of E-E transfer,... 

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