Behavior of ortho-positronium in low-temperature nitrogen

Journal Article · Fri Apr 15 00:00:00 EDT 1988 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.37.2855· OSTI ID:5344028

Kawaratani, T; Nakayama, Y; Mizogawa, T

Ortho-positronium (o-Ps) annihilation rates have been measured in N/sub 2/ at temperatures in the range 100--170 K. Deviations from the annihilation rates expected for free o-Ps are observed, and are analyzed by current models where applicable. A density-functional calculation using an optical potential indicates that the large deviations at higher densities are attributable to the formation of o-Ps--induced bubbles, and the o-Ps--N/sub 2/ scattering length is about 0.8 A. Analysis by the density-fluctuation model suggests, on the other hand, that the relatively small deviations observed at lower densities are due to the existing density fluctuations. A semiclassical approach is also attempted to apply to problems of the density of states and the annihilation rates of ortho-positronium in gases.

• Research Organization: Laboratory of Nuclear Radiation, Institute for Chemical Research, Kyoto University, Sakyo-Ku, Kyoto 606, Japan
• OSTI ID: 5344028
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 37:8; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640303* -- Atomic
Molecular & Chemical Physics-- Positronium
Muonium
& Muonic & Mesic Atoms & Molecules
74 ATOMIC AND MOLECULAR PHYSICS
ANNIHILATION
BASIC INTERACTIONS
BUBBLES
COLLISIONS
ELECTROMAGNETIC INTERACTIONS
ELEMENTS
FLUIDS
GASES
INTERACTIONS
KINETICS
LOW TEMPERATURE
MEASURING METHODS
MOLECULE COLLISIONS
NITROGEN
NONMETALS
POSITRON COLLISIONS
POSITRON-MOLECULE COLLISIONS
POSITRONIUM
SYMMETRY