Total-cross-section measurements for positron and electron scattering by O/sub 2/, CH/sub 4/, and SF/sub 6/

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.38.1207· OSTI ID:7159514

Dababneh, M S; Hsieh, Y; Kauppila, W E; Kwan, C K; Smith, S J; Stein, T S; Uddin, M N

Total cross sections (Q/sub T/'s) have been measured for 1--500-eV positrons and electrons scattered by O/sub 2/, CH/sub 4/, and SF/sub 6/ using a beam-transmission technique. The positron Q/sub T/'s are compared with the corresponding electron Q/sub T/'s for each target gas. It is found that the positron Q/sub T/'s are, in general, lower than the electron results. There are no prominent structures observed for positron scattering at low energies that would be comparable to the narrow shape resonances observed for electrons scattering from various molecules, such as SF/sub 6/. The positron Q/sub T/ curve for CH/sub 4/ reveals a significant increase in the vicinity of its positronium formation threshold, while the O/sub 2/ and SF/sub 6/ curves are monotonically increasing in this vicinity. At the highest energies investigated, there are indications of a tendency toward merging of the positron and electron Q/sub T/'s for these gases. Interesting similarities are found in a comparison of the present positron and electron Q/sub T/ curves for CH/sub 4/ with prior comparison measurements for argon.

• Research Organization: Department of Physics, Yarmouk University, Irbid, Jordan
• OSTI ID: 7159514
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 38:3; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKANES
ATTENUATION
COLLISIONS
CROSS SECTIONS
DATA
ELECTRON COLLISIONS
ELECTRON-MOLECULE COLLISIONS
ELEMENTS
ENERGY RANGE
EV RANGE
EXPERIMENTAL DATA
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
INFORMATION
MEASURING METHODS
METHANE
MOLECULE COLLISIONS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN
POSITRON COLLISIONS
POSITRON-MOLECULE COLLISIONS
SULFUR COMPOUNDS
SULFUR FLUORIDES
TOTAL CROSS SECTIONS