Accession Number:
ADD002402
Title:
Activated Aluminum Tracer Tag.
Descriptive Note:
Patent,
Corporate Author:
DEPARTMENT OF THE NAVY WASHINGTON D C
Personal Author(s):
Report Date:
1975-12-02
Pagination or Media Count:
4.0
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 27Algamma, alpha n22Na. 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:
Subject Categories:
- Metallurgy and Metallography
- Radioactivity, Radioactive Wastes and Fission Products
- Ammunition and Explosives