Electron scattering from the laser-excited (...6s6p[1]P|1) [1]3S8Ba

Abstract

Electron scattering from the laser-excited ( ... 6s6p 1P 1) level in 138Ba has been investigated. These investigations have been made involving de-excitations from the laser-excited ( ... 6s6p 1P1) level to the ( ... 6s2 1 S0) ground state as well as the ( ... 6s5d 1 D2) level. Further investigations were made into collisions involving the excitation of the ( ... 5d2 1D 2), ( ... 6p5d 1D2), ( ... 6s7s 1S0), and the ( ... ... 6s6d 1D 2) levels from the laser-excited ( ... 6s6p 1P 1) level. Measurements of various scattering intensities as a function of laser orientation and polarization were used to extract the electron impact coherence parameters which describe the time-inverse related transitions. The _, P+1 , and L+? parameters were determined for the inelastic ( ... 6s2 1S0) to ( ... 6s6p 1P1) excitation at impact energies of 6, 8, 11 and 16 eV, while the L?g,P+ 1, and 'h' parameters, along with the differential cross section, were determined for the excitation of the ( ... 6s6p 1 P1) level out of an isotropic ( ... 6s5d 1D 2) level at impact energies of 10 and 40 eV. The L?g,P+ 1, and 'h' parameters were also determined for the superelastic transitions to the ( ... 6s6p 1P1) level from the ( ... 6s7s 1S0) and ( ... 6s6d 1D2) levels at impact energies of 18.74 and 18.49 eV respectively, as well as for the transition to the ( ... 6s6p 1P 1) level from the unresolved ( ... 5d2 1D 2) and ( ... 6p5d 1D2) levels at 19.38 eV.