Surface- and volume-plasmon excitations in electron inelastic scattering on metal clusters - art. no. 043201

In this work we treat inelastic scattering of fast electrons on metal clust ers in the range of transferred energies above the ionization threshold. We demonstrate that in this energy range many-electron collective excitations , namely, the volume plasmons, provide dominating contribution to the diffe rential cross section resulting in its resonance behavior. The volume-plasm on resonances excited in the cluster during the collision decay via the ion ization process. We determine the resonance frequency and the autoionizatio n width of the volume plasmon excitations. In order to elucidate the role o f plasmon excitations, we calculate the differential cross section of the p rocess using two different approaches. We calculate the cross section in th e random-phase approximation using the Hartree-Fock wave functions as a bas is and accounting simultaneously for all single-particle and collective exc itations in the cluster. We compare the results of this approach with those obtained in the plasmon resonance approximation.