Electron impact ionization of L-shell in barium atoms

The bremsstrahlung and characteristic L-emission spectra excited by collisions of fixed energy electrons (3 to 45 keV) with free Ba atoms were studied. The X-ray emission was registered by the Si(Li) detector. The L-emission excitation cross sections have been made absolute by normalization on the simultaneously measured bremsstrahlung intensity using the known theoretical data concerning bremsstrahlung cross sections in the modified Bethe-Haitler formula. Ionization cross sections for the L1-, L2- and L3-subshells were deduced using the known values of the fluorescence yields, transition probabilities and the Coster-Kronig factors. (author)