An analysis of the modern theory of associative ionization (AI) is performed, and ways of its further development are discussed. The threshold behavior of the cross section of endothermic AI reactions is considered and it is shown that, in the quantum case, its dependence on the above-threshold energy E is strictly linear, i.e., significantly different from the E(3/2) law ensuing from the semiclassical theory. This has a simple explanation, since the matrix elements of the scattering operator are finite at E = 0 due to the tunneling effect. The possibility of describing the dynamics of an elementary AI event within the framework of the diffusion approximation is substantiated, and the conditions of applicability of the theory of "quantum chaos" to treating the spectrum of highly excited Rydberg molecules are examined. The quantum properties of the exothermic processes of AI and Penning ionization in the case of the states of the interacting atoms being autoionizing are discussed in detail. A comparison with the semiclassical theory is presented.
- metastable and Rydberg states of atoms and ionization in slow collisions of atoms
- the intermediate Rydberg complex
- TEMPERATURE DISSOCIATIVE RECOMBINATION
- DYNAMIC COUPLING PHENOMENA
- MOLECULAR EXCITED-STATES