A Time-Measurement System Based on Isotopic Ratios.
- Peter J.
- Duncan W.
- Jonathan L.
A time-measurement system can be built based on the ratio of gamma-ray peak intensities from two radioactive isotopes. The ideal system would use a parent isotope with a short half-life decaying to a long half-life daughter. The activities of the parent-daughter isotopes would be measured using a gamma-ray detector system. The time can then be determined from the ratio of the activities. The best-known candidate for such a system is the {sup 241}Pu-{sup 241}Am parent-daughter pair. However, this {sup 241}Pu-{sup 241}Am system would require a high-purity germanium detector system and sophisticated software to separate and distinguish between the many gamma-ray peaks produced by the decays of the two isotopes. An alternate system would use two different isotopes, again one with a short half-life and one with a half-life that is long relative to the other. The pair of isotopes {sup 210}Pb and {sup 241}Am (with half-lives of 22 and 432 years, respectively) appears suitable for such a system. This time-measurement system operates by measuring the change in the ratio of the 47-keV peak of {sup 210}Pb to the 60-keV peak of {sup 241}Am. For the system to work reasonably well, the resolution of the detector would need to be such that the two gamma-ray peaks are well separated so that their peak areas can be accurately determined using a simple region-of-interest (ROI) method. A variety of detectors were tested to find a suitable system for this application. The results of these tests are presented here.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 978014
- Report Number(s):
- LA-UR-07-3782; TRN: US1003781
- Resource Relation:
- Conference: Proceeding of the 48th Annual Meeting of The Institute of Nuclear Materials Management, Tucson, Arizona, USA, July 8-12, 2007.
- Country of Publication:
- United States
- Language:
- English
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