POSITRON LIFETIMES AGAINST ANNIHILATION IN METALS AND ALKALI HALIDES (thesis). Technical Report No. 43

Technical Report · Wed Mar 01 04:00:00 EST 1961

OSTI ID:4029610

Pollak, B L.D.

Experimental determinations of positron lifetimes in metals and alkali halides were carried out in order to check existing theories and to study the electronic aspects of the annihilation process. The lifetimes against annihilation were-determined in Cu, Ag, Mg, LiF, NaF, NaCl, NaBr, NaI, KCl, KBr, Kl, CsBr, and CsI. Previous work, both experimental and theoretical, is summarized. The positron source used was Na/sub 22/ which emits positrons with an 0.542Mev endpoint and almost simultaneously gives off a gamma ray of approximately 1.28-Mev energy. The time delay between the appearance of the 1.28- Mev gamma ray and the annihilation radistion (0.511 Mev) gave the positron lifetime. Curves of the time distribution of positron annhilations for the metals and alkali halides are given. The shortness of the observed positron lifetimes in the alkali halides supported the assumption that the positron is bound to the halogen ion. (M.C.G.)

• Research Organization: Washington Univ., St. Louis
• NSA Number: NSA-15-024207
• OSTI ID: 4029610
• Report Number(s): NP-10371
• Country of Publication: United States
• Language: English

Related Subjects

ALKALI METALS
ANNIHILATION
CESIUM BROMIDES
CESIUM IODIDES
COPPER
DIAGRAMS
DISTRIBUTION
GAMMA RADIATION
HALIDES
LIFETIME
LITHIUM FLUORIDES
MAGNESIUM
PARTICLE SOURCES
PHYSICS
POSITRONS
POTASSIUM BROMIDES
POTASSIUM CHLORIDES
POTASSIUM IODIDES
SILVER
SODIUM 22
SODIUM BROMIDES
SODIUM CHLORIDES
SODIUM FLUORIDES
SODIUM IODIDES