Radiation Detection Technology for Homeland Security

An analysis of gamma-ray data collected at traffic intersections in Northern Virginia

“…It is interesting to compare the detection frequency for each medical isotope with the frequency of use for each. [30], (ii): [7], (iv): [31] Table 2 shows the percent of radiopharmaceutical procedures that used each medical isotope [7], and the percent of anomalies that were identified as belonging to that isotope class (percent in the table includes only the medical isotope classes: Tc-99m, F-18, I-131, I-123, In-111, Lu-177, Tl-201). There are some intriguing discrepancies in this table that help underscore the complexity of this comparison.…”

“…Medical and industrial sources are unique within the radiation background because they are often manifested as discrete sources and not necessarily fixed or distributed. This also places these sources into a category of so-called nuisance sources when considered within the context of radiation monitoring for security applications [7].…”

“…Historically, efforts to characterize the radiation background have focused primarily on environmental measurements, and characterizations of nuisance sources have typically started from medical and/or industrial source usage statistics [7]. Each of these methods yields valuable and insightful information, however, neither produce a complete picture of what one might actually encounter in the field.…”