Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Influence of defects on positron transmission and annihilation in the lithium fluoride crystal

Journal Article · · Sov. Phys. - Solid State (Engl. Transl.); (United States)
OSTI ID:6465832
The positron implantation profile and the angular distribution of annihilation ..gamma.. quanta were determined for a lithium fluoride crystal under ..beta../sup +/ and ..gamma.. irradiation (/sup 22/Na source). The positron absorption coefficient of the irradiated crystal was ..cap alpha.. = 76.2 +- 1.5 cm/sup -1/. The angular distribution had a strong narrow component. After thermal bleaching of the crystal, ..cap alpha.. = 91.9 +- 1.5 cm/sup -1/, the narrow component made a smaller contribution to the angular distribution, and its half-width increased. The positron mobility was found to be ..mu.. = 18 +- 8 cm/sup 2/ x V/sup -1/ x sec/sup -1/. It is suggested that defects influence in two ways the fate of positrons in the lithium fluoride crystal: free positrons may be trapped by some defects (cationic vacancies) or annihilated in collisions with others (F centers). The defect concentration is estimated.
Research Organization:
State Pedagogical Institute, Birsk
OSTI ID:
6465832
Journal Information:
Sov. Phys. - Solid State (Engl. Transl.); (United States), Journal Name: Sov. Phys. - Solid State (Engl. Transl.); (United States) Vol. 26:5; ISSN SPSSA
Country of Publication:
United States
Language:
English