Photomagnetic positron annihilation effects
The annihilation characteristics of positrons in phosphorescent substances can be altered by illumination with uv light. This phenomenon and its quantitative aspects agree with the idea that some positrons capture an electron to form ortho- or para-positronium, and that the interaction with the excited triplet states of the illuminated phosphor molecules quenches positronium through spin conversion. Photomagnetic positronium spin conversion cross sections are very large, approximately 10/sup 4/..pi.. ..cap alpha../sup 2//sub 0/. They correspond to interaction ranges of about 30 A and are symptomatic of the wave mechanical behavior of positronium in matter. Analysis suggests that the photomagnetic effect proceeds by a process labeled spin flip in which ortho- and para-positronium interconvert under the simultaneous quenching of the excited triplet state to the singlet molecular ground state. 5 figures, 5 tables.
- Research Organization:
- New York Univ., NY
- OSTI ID:
- 6790629
- Report Number(s):
- CONF-770510-P4
- Journal Information:
- Adv. Chem. Ser.; (United States), Journal Name: Adv. Chem. Ser.; (United States) Vol. 175; ISSN ADCSA
- Country of Publication:
- United States
- Language:
- English
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Positronium quenching via collisions with triplet states of photomagnetic molecules
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Related Subjects
400500 -- Photochemistry
640303* -- Atomic
Molecular & Chemical Physics-- Positronium
Muonium
& Muonic & Mesic Atoms & Molecules
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR MOMENTUM
ANNIHILATION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BASIC INTERACTIONS
CROSS SECTIONS
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
INTERACTIONS
LEPTONS
LIFETIME
MULTIPLETS
PARTICLE PROPERTIES
PHOSPHORS
POSITRONIUM
POSITRONS
RADIATIONS
SCINTILLATION QUENCHING
SPIN
TRIPLETS
ULTRAVIOLET RADIATION