Self-oscillations in solid methane irradiated by electrons

Abstract

The formation of self-oscillations of temperature and concentration of radicals in an electron-irradiated methane film at low temperatures has been investigated experimentally and theoretically. Self-oscillations arise due to the activation nature of diffusion and radical recombination processes. Self-oscillations were studied experimentally by measuring the desorption of particles from an irradiated sample and theoretically by solving the kinetic equations for defects in a methane sample. Concentration self-oscillations of two types of particles have been found and investigated; namely, hydrogen atoms and CH3 radicals formed during the irradiation of methane by electrons. It is shown that with an increase in the irradiation intensity, the oscillation periods decrease, and the calculation value are of the order of magnitude observed in the experiment. A model of a manifestation of the self-oscillation of hydrogen molecule concentration during desorption is presented.