| Autor: |
Jenkins, Kelly, Woodring, Mitchell, Walters, William, Moore, Angela, Simpson, Cheslan, Lintereur, Azaree |
| Předmět: |
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| Zdroj: |
Journal of the Institute of Nuclear Materials Management; 2022, Vol. 50 Issue 3, p5-21, 17p |
| Abstrakt: |
The United States National Nuclear Security Administration's (NNSA) Office of Nuclear Smuggling Detection and Deterrence (NSDD) has developed sophisticated testing protocols for radiation detection instrumentation that may be used in programmatic deployments. These protocols include measurements to quantify how this instrumentation will respond to some of the most commonly encountered medical radioisotopes, including Mo-99/Tc-99m, Ga-67, and I-131, as these sources can have low energy gamma-ray emissions similar to special nuclear material (SNM). However, research into alternative nuclear medicine treatments has resulted in the use of approximately 200 other isotopes, some of which also emit gamma-rays with energy signatures similar to SNM. Therefore, it is necessary to consider the potential impact of these alternative medical isotopes on detection systems commonly used in nuclear security to find illicit material. This study provides preliminary insight into the potential identification capabilities of both HPGe and NaI(Tl) detectors to two examples of emerging medical radiotherapies, Lu-177 and Ra-223. The detector responses were simulated using the Gamma Detector Response and Analysis Software (GADRAS). The two sources were modeled within a standard human phantom, and the detectors' ability to produce a correct identification was determined using three different analysis techniques available in GADRAS as a function of different source-to-detector distances. HPGe has better energy resolution than NaI(Tl) and is thus better able to resolve peak energies. However, other factors such as dead-time and weak signatures at large distances also affected the results. Further, the analysis technique used was found to affect the identification accuracy. The results indicate there is a need for further research into the evolving global medical use of radioisotopes, with experimental evaluation of commercial systems and algorithms due to the high probability of false identification, and thus nuisance alarms, observed in this study. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
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