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We present the results of quasiclassical trajectory simulation of dissociation of CsBr molecules in collisions with Xe atoms (at collision energies ranging from 3 to 12 eV) on two diabatic potential energy surfaces differing in the parameters of the potential well and of the repulsive wall for the pairwise interaction potential between the xenon atom and the bromide anion. The dynamical characteristics of both the dissociation channels (of the formation of the atomic ions and of that of the ionic complex XeCs+) are practically independent of the interaction potential between Xe and Br–. [ABSTRACT FROM AUTHOR]

A method for recording time-of-flight spectra of hyperthermal gas-dynamic seeded molecular beams of alkali and alkaline earth metal halides is described. This method is free of the need to determine and adjust spectra taking hardware time delays into account. The method is based on registering ions, which are formed in the collision-induced dissociation (CID) of molecules with ionic bonds, by two secondary-electron multipliers located at different distances from the beam chopper along the beam passage. [ABSTRACT FROM AUTHOR]

Within the framework of the quasiclassical trajectory method on semiempirical diabatic potential energy surfaces, we have considered the existence regions for direct three-body recombination Cs+ + Br– + R → CsBr + R (R = Kr, Xe, Hg) in the case where the encounters of the Cs+ and Br– ions are central and the delay parameter vanishes. The recombination regions are determined using a much more precise procedure than in the previous works. Particular attention is paid to the recombination opacity functions and to the role of the orientation angles in the outcome of a three-body collision. The performed calculations demonstrate a great complexity of the structure of the recombination regions. [ABSTRACT FROM AUTHOR]

Within the framework of the quasiclassical trajectory method and using semiempirical diabatic potential energy surfaces, we have studied statistical dynamics of two reactions of direct three-body recombination, Cs+ + X– + Kr → CsX + Kr (X– = F–, I–), with non-central encounters of the ions. The collision energies range between 1 and 10 eV, while the so-called delay parameter, which characterizes the delay in the arrival of the krypton atom with respect to the time instant when the distance between the recombining cesium and halide ions attains its minimum, is equal to 0 or 0.2. We have found the excitation functions of recombination, the opacity functions, the vibrational energy distributions of the CsX product (which turn out to be strongly non-equilibrium), and the CsX rotational energy distributions (which are almost equilibrium). A comparison with the calculation results for the reactions Cs+ + X– + Ar and Cs+ + X– + Xe published earlier shows that, on the whole, for both the recombining ion pairs Cs+ + F– and Cs+ + I–, the heavier the third body, the more effective it is as an acceptor of excess energy of the ion pair. [ABSTRACT FROM AUTHOR]

We propose a hard sphere model of bimolecular recombination RM+ + X– → MX + R, where M+ is an alkali ion, X– is a halide ion, and R is a neutral rare gas or mercury atom. Calculations are carried out for M+ = Cs+, X– = Br–, R = Ar, Kr, Xe, Hg, for collision energies in the range from 1 to 10 eV, and for distributions of the RM+ complex internal energy corresponding to temperatures of 500, 1000, and 2000 K. The excitation functions and opacity functions of bimolecular recombination in the hard sphere approximation are found, and the classification of the collisions according to the sequences of pairwise encounters of the particles is considered. In more than half of all the cases, recombination occurs due to a single impact of the Br– ion with the R atom. For the recombination XeCs+ + Br–, the hard sphere model enables one to reproduce the most important characteristics of the collision energy dependence of the recombination probability obtained within the framework of quasiclassical trajectory calculations. [ABSTRACT FROM AUTHOR]

The design of a source of a seeded supersonic beam of alkali halide molecules or other vaporized solids is described. At a carrier gas (hydrogen or helium) stagnation pressure of 0.5–5 atm, a stagnation temperature of 1000 K, and a partial seed species pressure of 10–2 Torr, the intensity of the salt beam was 1014 sr–1 s–1 and the energy of molecules in the beam varied from 5.5 to 7.5 eV for a mixture with helium and from 7.5 to 15.5 eV for a mixture with hydrogen. The modular design of the source provides the easy replacement of its functional units. [ABSTRACT FROM AUTHOR]

We compare the dynamics of two elementary reactions of recombination of atomic ions, namely, of the termolecular process of two ions and the third body (1) and of the bimolecular interaction of an ion with the diatomic cluster (2) consisting of the second ion and the neutral atom. It is shown that, despite the fact that both processes yield the same products, the main dynamical characteristics of these processes differ. First of all this concerns the excitation function which confines recombination for (2) by a collision energy up to 2 eV. The opacity functions of both processes have different structures. The distributions of the product vibrational energy in both the processes exhibit a non-equilibrium character, while the rotational energy distributions are equilibrium. [ABSTRACT FROM AUTHOR]