MANY-BODY TREATMENT OF ELECTRON INELASTIC-SCATTERING ON METAL-CLUSTERS

In this paper we suggest the many-body treatment for the inelastic sca ttering of fast electrons on metal clusters. The accurate many-body th eory for this process is necessary because electrons in the cluster ex perience collective excitations during the collision. We perform our c alculation in the random phase approximation with exchange using the w avefunctions of the Hartre-Fock jellium model and also in the plasmon resonance approximation. The latter approach is appropriate to treat c ollective excitations in clusters. We analyse the differential and tot al inelastic scattering cross sections and elucidate the relative impo rtance of collective electron excitations and single-electron transiti ons in the formation of the inelastic scattering cross section on meta l clusters. We perform this calculation for the magic sodium clusters Na-20, Na-40, Na-58 and Na-92. Theoretical results are also compared w ith the experimental data available for electron collisions with the N a-8, Na-20 and Na-40 clusters. We report some discrepancy between theo retical and experimental results.