CROSS-SECTIONS FOR ELECTRON-SCATTERING BY GROUND-STATE BA - ELASTIC-SCATTERING AND EXCITATION OF THE ... 6S6P(1)P1 LEVEL

Differential cross sections for elastic and inelastic (6s6p P-1(1)) el ectron scattering from ground state Ba atom have been measured at 5 eV , 10 eV, 15 eV and 20 eV impact energies in the angular range from 0-d egrees to 130-degrees. Extrapolation to larger angles has been perform ed using theoretical calculations as a guide, and integral and momentu m transfer cross sections were derived. Theoretical calculations based on two-channel close coupling and relativistic and non-relativistic d istorted wave methods have been compared with the present results. Goo d agreement between experiment and various theoretical results is foun d at small scattering angles but significant deviations exist at large r scattering angles.