Absolute doubly differential cross sections for ejection of secondary electrons from gases by electron impact. I. 100- and 200-eV electrons on helium
We have measured absolute values of the cross sections for ejection of electrons from helium gas by 100- and 200-eV electrons. These cross sections were measured for emission angles from 10/sup 0/ to 150/sup 0/ and for electron energies from 3 eV to a value equal to the primary energy minus the ionization potential. The measurements were made using a static-gas target and an electrostatic analyzer. The resulting cross sections agree reasonably well with those of Opal, Peterson, and Beaty near 90/sup 0/, but show the need for an adjustment of their angular distributions. Comparison with Born-approximation calculations of Manson et al. at 2 keV indicate that the cross sections of Opal et al. should be divided by 0.53 + 0.47 sintheta. A somewhat larger correction is needed to bring their data into agreement with the results of this experiment. The adjustment in the angular distributions also affects the cross sections integrated over all angles.
- Research Organization:
- Behlen Laboratory of Physics, University of Nebraska, Lincoln, Nebraska 68588
- OSTI ID:
- 7219652
- Journal Information:
- Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 16:1; 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
ATOM COLLISIONS
COLLISIONS
CROSS SECTIONS
CRYOGENIC FLUIDS
DIFFERENTIAL CROSS SECTIONS
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ELEMENTS
EMISSION
ENERGY RANGE
EV RANGE
EV RANGE 100-1000
FLUIDS
HELIUM
IONIZATION
NONMETALS
RARE GASES
SECONDARY EMISSION