Two-photon mechanism of formation of a continuous optical emission spectrum of metal sputtering products

A two-photon mechanism of formation of a continuous spectrum of photons emitted by metal sputtering products according to which after strong interatomic interactions in the sputtering act the electron in the atom knocked out of the deeply layed shell gets into the excited level (nl)sup(*) located opposite to the filled part of the conductivity zone, and then spontaneously transfers into the nl state with radiation of two photons, is proposed. This mechanism qualitatively explains the experimentally observed effect of the electron shell structure of sputtered atoms on the possibility of formation of the continuous spectrum and the intensity of corresponding radiation, and, in particular, the causes of the fact that the radiation under consideration is emitted only by metals with open d- and f- shells and that radiation of lanthanides essentially exceeds radiation of transition metals. The estimated probabilities of formation of the continuous spectrum, its ultraviolet boundaries and widths of the spatial radiation distribution are in good agreement with the experimental data as well