Accession Number : ADD002402
Title : Activated Aluminum Tracer Tag.
Descriptive Note : Patent,
Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C
Personal Author(s) : Murray,Kenneth M
Report Date : 02 Dec 1975
Pagination or Media Count : 4
Abstract : The patent concerns a method of treating a piece of aluminum and detecting the presence of the treated aluminum in an assembly without disassembly of the parts. The small piece of aluminum is made radioactive by irradiation with x-rays of at least 23 MeV to produce the reaction 27Al(gamma, alpha n)22Na. The presence of the aluminum part is determined by isotope decay which emits a positron. The positron subsequently annihilates emitting two 180 degree correlated 0.511006 MeV gamma rays. These gamma rays are detected in coincidence by use of a pair of detectors and associated coincidence and counting electronics. Part of a primer of a naval shell contains an aluminum shear pin which is to be detected. A counting system is used to detect positrons from the 22Na activity in the shear pin.
Descriptors : *Aluminum, *Tracer studies, *Detection, *Patents, Irradiation, Electromagnetic radiation, Naval guns, Ammunition, Pins
Subject Categories : Metallurgy and Metallography
Radioactiv, Radioactive Wastes & Fission Prod
Ammunition and Explosives
Distribution Statement : APPROVED FOR PUBLIC RELEASE