Angle-resolved electron energy loss study on the inner-shell excited states of Ne

Electron energy loss spectra in the region below and above the Ne Is ioniza tion threshold have been measured at several scattering angles between 2.4 degrees and 24.4 degrees and at a fixed scattered electron energy of 1.6 ke V, while the impact energy has been scanned from 2.46 to 2.52 keV. Singly a nd doubly excited core states, corresponding to 1s --> nl and 1s2p --> nln' l' transitions, respectively, have been observed. The generalized oscillato r strengths for both types of excitations have been derived from the angula r variation of the double differential cross section and ab initio calculat ions have been performed using two methods based on a configuration-interac tion approach.