ELECTRON ATTACHMENT TO THE SF₆ MOLECULE
Smirnov B.M., Kosarim A.V.

Received: January 21, 2015

DOI: 10.7868/S0044451015090011

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Various models for transition between electron and nuclear subsystems are compared in the case of electron attachment to the SF₆ molecule. Experimental data, including the cross section of electron attachment to this molecule as a function of the electron energy and vibrational temperature, the rate constants of this process in swarm experiments, and the rates of the chemionization process involving Rydberg atoms and the SF₆ molecule, are collected and treated. Based on the data and on the resonant character of electron capture into an autodetachment ion state in accordance with the Breit-Wigner formula, we find that intersection of the molecule and negative ion electron terms proceeds above the potential well bottom of the molecule with the barrier height 0.05-0.1 eV, and the transition between these electron terms has both the tunnel and above-barrier character. The limit of small electron energies for the electron attachment cross section at room vibrational temperature takes place at meV, while in the range 2 meV\ll \varepsilon \ll 80 meV, the cross section is inversely proportional to . In considering the attachment process as a result of the interaction between the electron and vibrational degrees of freedom, we find the coupling factor f between them to be f=aT at low vibrational temperatures T with K^-1. The coupling factor is independent of the temperature at T>400 K.