Accession Number : AD0635169

Title :   A MULTIPLE DETECTOR SYSTEM ADAPTED FOR TOTAL ABSORPTION GAMMA-RAY SPECTROMETRY.

Corporate Author : ARMY NUCLEAR DEFENSE LAB EDGEWOOD ARSENAL MD

Personal Author(s) : SACCENTI, John C. ; Brady,Robert E. ; McNeilly,John H.

Report Date : JUN 1966

Pagination or Media Count : 24

Abstract : A total absorption gamma-ray spectrometer system utilizing anticoincidence shielding is described. The multi-detector system consists of a 9.50-inch diameter, 10.0-inch high NaI(T1) crystal annulus which serves as the anticoincidence guard. A 3.31-inch-diameter cylindrical cavity extends completely through, and is symmetric with, the crystal axis. Two additional NaI(T1) crystals are positioned within the annulus cavity; one is removable for inserting samples. With the anticoincidence shielding, a factor of 6 reduction in the magnitude of the Compton portion of the cesium-137 spectrum can be achieved. For cobalt-60, the maximum reduction factor achievable is 25. For gamma energies less than 3 MeV, background is reduced by a factor of 3.3. Design flexibility permits coincidence, anticoincidence, and sumcoincidence operation. The system has effectively been used as an anticoincidence total absorption spectrometer, in coincidence for positron annihilation studies, and as an integral bias sum spectrometer. (Author)

Descriptors :   (*NUCLEAR RADIATION SPECTROMETERS, *CRYSTAL DETECTORS), ABSORPTION SPECTRA

Subject Categories : Nuclear Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE