Inner Shell Excitations of Lithium Studied by Fast Electron Impact

Electron energy loss spectra for the inner shell excitations of atomic lithium are measured at an incident electron energy of 2500eV and scattering angles of 0°, 2°, 4° and 6°. Two optically forbidden transitions of (1s2s²)²S and (1s2s³S)3s²S are observed. The generalized oscillator strength ratios for
1s(2s2p³P)²P⁰ to 1s(2s2p¹P)²P⁰ were determined, and they are independent of the momentum transfer.