ELASTIC ELECTRON-SCATTERING BY LASER-EXCITED BA-138(...6S6P P-1(1)) ATOMS

The results of a combined experimental and theoretical study of elasti c electron scattering by laser-excited Ba-138(...6s6p P-1(1)) atoms ar e presented. From these studies, we extracted differential scattering cross sections and parameters for elastic scattering both by coherentl y prepared P-1(1) Pa atoms and by Ba atoms in an isotropic, incoherent state of the P-1(1) level. This is the first time that results of thi s type have been reported for elastic scattering by excited atoms. Goo d agreement was found between the limited experimental results and tho se obtained from our convergent close-coupling (CCC) theoretical calcu lations. It was demonstrated that elastic scattering can create alignm ent with significant probability.