Evidence for age-related performance degradation of 241Am foil sources commonly used in UK schools
Autor: | P Cole, Robert Page, Ralph Whitcher |
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Rok vydání: | 2014 |
Předmět: |
Americium
Schools Detector Public Health Environmental and Occupational Health Reproducibility of Results Equipment Design General Medicine Alpha Particles Sensitivity and Specificity United States Specimen Handling Equipment Failure Analysis Radiation Monitoring Reference Values Age related Materials Testing Statistics Environmental science Waste Management and Disposal FOIL method Half-Life Degradation (telecommunications) |
Zdroj: | Journal of Radiological Protection. 34:347-361 |
ISSN: | 1361-6498 0952-4746 |
Popis: | The characteristics of alpha radiation have for decades been demonstrated in UK schools using small sealed (241)Am sources. There is a small but steady number of schools who report a considerable reduction in the alpha count rate detected by an end-window GM detector compared with when the source was new. This cannot be explained by incorrect apparatus or set-up, foil surface contamination, or degradation of the GM detector. The University of Liverpool and CLEAPSS collaborated to research the cause of this performance degradation. The aim was to find what was causing the performance degradation and the ramifications for both the useful and safe service life of the sources. The research shows that these foil sources have greater energy straggling with a corresponding reduction in spectral peak energy. A likely cause for this increase in straggling is a significant diffusion of the metals over time. There was no evidence to suggest the foils have become unsafe, but precautionary checks should be made on old sources. |
Databáze: | OpenAIRE |
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