The size effect in desorption of excited atoms and molecules out of inert element clusters by electron bombardment

New desorption channels of excited atoms and molecules out of argon, krypton and xenon clusters first were revealed for the first time by the emission vacuum ultraviolet spectroscopy method under electron bombardment. A maximum yield of particles was registered within an average size range 50-100 atom/cluster. Regularities and features of the desorption of excited particles are found out, permitting a new desorption mechanism named a 'nonradiative excimer dissociation' mechanism to be established. It is shown that the main stages of this mechanism are as follows: (i) the formation of molecule centers of the high-excitation two-atom excimer molecules type in inert element clusters due to the self-trapping of high-energy p-excitons (n = 1); (ii) the nonradiative dissociation into excited atoms and ground-state ones with high kinetic energies. It is found, that the appearance of the new desorption channels of exited atoms and molecules out of inert element clusters at electron bombardment is connected with the features of the physical properties of clusters within the average size range 50-100 atom/cluster, in particular, with the features of the energy spectrum, the vibrational frequency spectrum of atoms and the relaxation of exciton energy