Positron annihilation in gaseous hydrogen and hydrogen-neon mixtures. I. Low-energy positrons

Journal Article · Sun Jul 01 04:00:00 EDT 1979 · Phys. Rev., A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.20.347· OSTI ID:6128946

McNutt, J D; Sharma, S C; Brisbon, R D

Annihilation lifetime spectra have been measured for positrons in H/sub 2/ gas at 293, 250, and 77 K at densities in the range 5.9--429 amagat, and in H/sub 2/-Ne gas mixtures at 77 K having H/sub 2/ partial densities in the range 1.9--286 amagat and with Ne concentrations in the range 0.02--0.98. The annihilation rate of slow positrons with H/sub 2/ has a complex dependence on gas density and temperature. Particularly at low H/sub 2/ densities, the presence of various partial densities of Ne can dramatically affect the positron-H/sub 2/ annihilation process. The slow-positron annihilation rates are discussed in terms of positron-H/sub 2/ collision complexes and the self-trapping of positrons within clusters of H/sub 2/ molecules. The annihilation in H/sub 2/ of positrons bound in Ps atoms is discussed in paper II of this series.

• Research Organization: Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019
• OSTI ID: 6128946
• Journal Information: Phys. Rev., A; (United States), Journal Name: Phys. Rev., A; (United States) Vol. 20:1; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640303 -- Atomic
Molecular & Chemical Physics-- Positronium
Muonium
& Muonic & Mesic Atoms & Molecules
640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ANNIHILATION
BASIC INTERACTIONS
COLLISIONS
CRYOGENIC FLUIDS
ELECTROMAGNETIC INTERACTIONS
ELEMENTS
FLUIDS
HYDROGEN
INTERACTIONS
LIFETIME
LOW TEMPERATURE
MOLECULE COLLISIONS
NEON
NONMETALS
POSITRON COLLISIONS
POSITRON-MOLECULE COLLISIONS
POSITRONIUM
RARE GASES
TEMPERATURE DEPENDENCE