Xz. Guo et al., Differential cross sections for electron-impact excitation of krypton at low incident energies: I. Excitation of the 4p(5)5s configuration, J PHYS B, 33(10), 2000, pp. 1895-1919
Citations number
52
Categorie Soggetti
Physics
Journal title
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
The electron-impact excitation of the individual levels that constitute the
4p(5)5s configuration of Kr is experimentally and theoretically investigat
ed at incident electron energies of 20.0, 15.0, 13.5 and 12.0 eV, for scatt
ering angles ranging from 10 degrees to 135 degrees. High resolution electr
on energy-loss spectroscopy is used to obtain spectral intensities for the
excitation of each of the four 4p55s levels from the ground state. The inte
nsities lead to three differential cross section ratios. Absolute electron-
impact excitation cross sections are then determined by normalization to el
astic scattering cross sections using the conventional inelastic to elastic
normalization method. The present theoretical cross sections are calculate
d using two different methods, namely the R-matrix method and the unitarize
d first-order many-body theory. Comparisons between the experimental and th
e theoretical results show some good agreement, but reveal areas where sign
ificant improvement of the present models is needed. Additionally, it is sh
own that in the present case, just as in general for the rare gases, differ
ential cross section ratios provide a sensitive test of theoretical models
as well as unique insights concerning relativistic effects in the scatterin
g process. Comparisons with existing models and other experimental data are
also presented.