Positron annihilation in gaseous hydrogen and hydrogen-neon mixtures. II. Positronium

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

DOI:https://doi.org/10.1103/PhysRevA.20.357· OSTI ID:6248366

McNutt, J D; Sharma, S C; Franklin, M H; Woodall, II, M A

The annihilation rate of positrons bound in o-Ps atoms and the fraction of positrons which form Ps have been measured for H/sub 2/ gas at 293, 250, and 77 K at densities in the range 5.9--429 amagat, and for 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. Large deviations from the annihilation rates expected for free o-Ps atoms are observed and are attributed to the formation of localized cavity states. The results obtained with H/sub 2/-Ne mixtures strongly support o-Ps-induced cavity formation. Complex density and temperature dependencies are observed for the Ps fraction in H/sub 2/, and the addition of partial densities of Ne enhances positronium formation. The annihilation of slow positrons in H/sub 2/ is discussed in paper I of this series.

• Research Organization: Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019
• OSTI ID: 6248366
• 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
CROSS SECTIONS
CRYOGENIC FLUIDS
ELECTROMAGNETIC INTERACTIONS
ELEMENTS
FLUIDS
HYDROGEN
INTERACTIONS
LOW TEMPERATURE
MOLECULE COLLISIONS
NEON
NONMETALS
POSITRON COLLISIONS
POSITRON-MOLECULE COLLISIONS
POSITRONIUM
RARE GASES
TEMPERATURE DEPENDENCE