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