Calculation of excitation cross sections for the lowest five dipole-allowed transitions in scattering
Zhifan Chen; Alfred Z Msezane; Zhifan Chen; Center for Theoretical Studies of Physical Systems, and Department of Physics, Clark Atlanta University, Atlanta, GA 30314, USA; Alfred Z Msezane; Center for Theoretical Studies of Physical Systems, and Department of Physics, Clark Atlanta University, Atlanta, GA 30314, USA
Журнал:
Journal of Physics B: Atomic, Molecular and Optical Physics
Дата:
1996-04-28
Аннотация:
Two methods have been used in the calculation of the integral excitation cross sections (ICSs) for the first time for the lowest five dipole-allowed transitions in e - scattering in the energy range from 200 to 1000 eV. The first method uses the universal extrapolation function together with the differential cross sections (DCSs) data, while the other uses Lassettre's equation and the Bethe theory. Good agreement has been obtained between the two methods at 500 eV. The calculation demonstrates that a significant contribution to the ICS comes from small scattering angles () where the experimental data are not available. Therefore a good extrapolation function is necessary in the calculation of the ICS from the DCS measurement in order to avoid the large uncertainties in the region of small scattering angles.
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