Differential cross sections for electron impact excitation of Xe .1. Excitation of the five lowest levels; Experiment and theory

Experimental and theoretical differential cross sections (DCSs) for electron impact excitation of the five lowest levels of xenon are reported. The experimental data were obtained at impact energies of 10, 15, 20 and 30 eV for scattering angles in the range of 0 degrees to 135 degrees. The scattering intensities for excitation of various levels with respect to that of the combined two lowest levels (representing the corresponding DCS ratios) were measured with conventional electrostatic electron energy-loss spectrometers. Absolute DCSs for excitation of the combined two lowest levels were derived from DCS ratios for excitation of the combined two lowest levels and elastic scattering and utilizing the elastic DCSs of Register et al. These DCS ratios were obtained from scattering intensity ratios measured with conventional electrostatic electron energy-loss spectrometers after correction for instrumental effects by utilizing electron time-of-flight measurements for determining the proper value of this ratio at 90 degrees scattering angle for each impact energy. The unitarized first-order many-body theory and the unitarized distorted-wave approximation were applied to obtain the theoretical differential cross sections for impact energies of 10, 15, 20, 30, 50 and 80 eV. The present experimental and theoretical results are compared with each other and with other available experimental and theoretical DCSs.