Accession Number : AD0663113

Title :   MEASUREMENT OF POSITRON ANNIHILATION INTERACTIONS WITH A GE(LI) DETECTOR,

Corporate Author : NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Personal Author(s) : Hotz,Henry P. ; Mathiesen,James M. ; Hurley,John P.

Report Date : 15 DEC 1967

Pagination or Media Count : 29

Abstract : It was observed that the annihilation radiation photopeak in a Ge(Li) detector is considerably broader than that of a gamma-ray of the same energy. It seems reasonable to assume that the increased width is the result of the Doppler broadening of the annihilation photopeak, i.e., the longitudinal Doppler shift of the radiations is measured, while the transverse shift is measured in the usual angular correlation experiments. By using a computer stripping program to remove the distortion produced by the finite energy resolution of the detector, momentum distributions are obtained which are in agreement with those which have been published. Only one detector is necessary for these measurements and all momenta channels are detected at once. However detector energy resolution severely limits the momentum resolution. Arguments are presented which indicate that no very large improvement in Ge(Li) detector resolution can be expected. (Author)

Descriptors :   (*ANNIHILATION RADIATION, DOPPLER EFFECT), (*RADIATION MEASURING INSTRUMENTS, ANNIHILATION RADIATION), (*CRYSTAL COUNTERS, ANNIHILATION RADIATION), POSITRONS, ANNIHILATION REACTIONS, MOMENTUM, POLYETHYLENE PLASTICS, SILVER, BERYLLIUM, SEMICONDUCTOR DEVICES, GALLIUM, IMPURITIES, LITHIUM

Subject Categories : Nuclear Instrumentation
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE