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CORVALLIS, Ore. - New radiation detection technology being developed at Oregon State University could assist in the tracking of nuclear weapons testing by identifying the presence of radioactive gases in the atmosphere within 24 hours of an underground detonation.

A new three-year, $1.25 million grant from the National Nuclear Security Administration will help David Hamby, a professor in the Department of Nuclear Engineering and Radiation Health Physics, develop a stand-alone device that could be placed near the borders of countries suspected of detonating nuclear weapons.

These devices, which will be capable of identifying trace amounts of airborne radioactive isotopes associated with nuclear fission, will ultimately include a compact weather station, a scintillating detector called a "phoswich" and a small computer system for digital data analysis and transmission. The technology builds on earlier detection methods, but provides more detailed information from each data reading than other devices, Hamby said.

"We are combining various ideas to look at blast detection in different ways," said Hamby, who is coordinating this research in collaboration with OSU doctoral candidate Abi Farsoni. "New to this application is the capability for digital pulse analysis. We can direct the phoswich data through a circuit to create a digital pulse, which we can then identify as a specific radiation and energy type. Each signal pulse carries a unique signature."

According to Hamby, a covert nuclear weapons test is most likely to occur underground, with two common results: the release of energy and the production of radioactive isotopes. This includes the noble gas xenon, which is a key isotope for detection because of the speed in which it vents into the air, its discernable differences from other gases and its limited presence in the Earth's atmosphere. Once in open air, radioactive xenon is picked up by wind currents and could be analyzed by the detection system.

With reasonable wind speeds and proper placement of the device, the detection system could recognize the presence of xenon within 12-24 hours of an underground nuclear detonation, Hamby said.

After confirmed detection, the blast data could be reported back to governmental bodies or the Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization. This is an international organization to enforce the Comprehensive Nuclear Test Ban Treaty, which seeks to ban nuclear weapon testing, drastically limit the improvement of current nuclear weapons and restrict the development of new nuclear weapons.

"This could provide a service for the global community," Hamby said. "Use of the phoswich detector could help assure compliance with the test ban treaty and have a definitive impact on the use and testing of nuclear weapons."

This work on phoswich detectors has been published most recently in Nuclear Instruments and Methods in Physics Research, a professional journal.