LEFT-RIGHT ASYMMETRIES IN ELASTIC AND INELASTIC-SCATTERING OF POLARIZED ELECTRONS FROM ARGON, KRYPTON AND XENON ATOMS

Polarized electrons were scattered from unpolarized argon, krypton and xenon atoms with scattering angles ranging from 30 degrees to 125 deg rees. For xenon elastic left-right asymmetries were measured at energi es ranging from 1.5 to 10 eV. Inelastic scattering asymmetries were ob served for argon, krypton and xenon at energies between 10 and 40 eV. For inelastic scattering from argon and krypton it could be shown that exchange, in conjunction with the spin-orbit coupling within the targ et atom, is the dominant mechanism for scattering asymmetries. For the heavy xenon, on the other hand, this simple mechanism is not sufficie nt to describe the observed spin effects. A comparison with theoretica l data shows good agreement for elastic scattering from xenon, whereas , in the case of inelastic scattering, the theoretical predictions are rather unsatisfactory.