Product velocity distribution

As an example, figure A3.7.5 shows a polar contour plot of the HE product velocity distribution at a reactant... 

Rakitzis T P, Kandel S A and Zare R N 1997 Determination of differential-cross-section moments from polarization-dependent product velocity distributions of photoinitiated bimolecular reactions J. Chem. Phys. 107 9382-91... 

Various methods have been proposed for measuring the product velocity distributions from the Doppler absorption profile of the laser-induced fluorescence from the products. In one case, it has been suggested [115] that the velocity distribution of the H atom from... 

Rectangular velocity or energy spectra are not often observed because slow statistical dissociations of polyatomics form the products in a distribution of the translational energies, or because nonstatistical and direct dissociations generally are not characterized by isotropic product velocity distributions. 

Measurement of product velocity distributions was not feasible in the D + H2 study however, even in experiments where the recoil velocity. distribution is accurately measured, it is diflBcult to extract a c.m. cross section due to the diflBculty of estimating a resolution that depends on beam shapes, detector geometry, and electron density gradients in the ionizer. 

Finally, mention must be made of the type of control experiment which has often been considered sufficient in the past, namely the reproduction of an accepted rate constant for a standard reaction, usually CH4 (CH4,CH3)CH5 . Such reproduction establishes that detection efficiencies of reactant and product ions are equal for this reaction, but this may not be so for other reactions where the initial product velocity distributions differ. Second, it may well not reveal the presence of errors which cancel one another (see Section 3.2.2). Third, this particular reaction is unsuitable as a standard since its rate constant is rather insensitive to Ef, accordingly, it cannot be used to establish the homogeneity of the field within the chamber, a necessary condition if [Eq. (11)] is to be identified with k(Vf) [Eq. (15)]. 

Two other techniques should be mentioned in connection with beam methods. They are essentially single-chamber and double-chamber spectrometric techniques, but since they can provide information concerning product velocity distributions, their results are relevant here. 

Product velocity distribution. Is the collision energy channelled into product translation and/or internal excitation ... 

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