Factorized distorted-wave approximation for the (e,2e) reaction on atoms: Coplanar symmetric
The coplanar symmetric (e,2e) cross section has been studied in the intermediate-energy region for the valence states of the inert gases He, Ar, and Ne. Experimental measurements at 200, 400, 800, and 1200 eV for He, and at 400, 800, and 1200 eV for Ne and Ar, are compared with calculations based on the factorized half-off-shell distorted-wave impulse approximation. Calculations are carried out using partial-wave-expanded optical-model wave functions which describe elastic scattering for the distorted waves, the eikonal approximation, and the plane-wave approximation. The latter two significantly overestimate the cross sections at small angles and the valence s-orbital cross section relative to the valence p-orbital one. They also predict the small-angle peak in the p-orbital cross section to be at an angle significantly smaller than is observed. Of the two, the eikonal approximation provides the better description of the data. The full calculation, on the other hand, underestimates the cross sections at small angles and the cross section for the more tightly bound s-orbital relative to the small-angle p-orbital cross section. It also underestimates the ratio of the large- to small-angle peak heights in the p-orbital cross section. All three approximations improve as the energy is increased. The full calculation shows that the factorized distorted-wave impulse approximation cannot provide an adequate description of the reaction.
- Research Organization:
- Institute for Atomic Studies, The Flinders University of South Australia, Bedford Park, South Australia 5042, Australia
- OSTI ID:
- 5162948
- Journal Information:
- Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 17:2; ISSN PLRAA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOM COLLISIONS
BEAMS
BORN APPROXIMATION
COLLISIONS
CROSS SECTIONS
CRYOGENIC FLUIDS
DWBA
ELECTRON BEAMS
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ELEMENTS
ENERGY RANGE
EV RANGE
EV RANGE 100-1000
FLUIDS
HELIUM
IONIZATION
KEV RANGE
KEV RANGE 01-10
LEPTON BEAMS
NEON
NONMETALS
PARTICLE BEAMS
RARE GASES