Paul Johns and Juan Nino, from the University of Florida and Pacific Northwest National Laboratory, researched new ways to enhance global nuclear security by improving radiation detectors with the aim being to enhance the safety of trafficking of nuclear materials.
In their study, published in the Journal of Applied Physics, Johns and Nino believe that identification of better sensor materials, as well as the development of smarter algorithms to process detector signals, are needed to improve radiation detectors.
“The end users of radiation detectors don’t necessarily have a background in physics that allows them to make decisions based on the signals that come in,” Johns said. “The algorithms used to energy-stabilize and identify radioactive isotopes from a gamma ray spectrum are therefore key to making detectors useful and reliable.”
“When sensors can provide better signal resolution,” he continued, “algorithms are able to more accurately inform users about the radiation sources in their environment.”
Designing the perfect radiation detector is no easy feat. Specific size, signal resolution, weight, and cost are all factors in designing each detector. Johns and Nino chose a compound for a room temperature semiconductor detector, which doesn’t need to cool sensors down to cryogenic temperatures to function. They considered cost, practicality, and efficiency of each possible compound before narrowing down their search.
Johns and Nino chose hybrid organic-inorganic perovskite — a mineral consisting mainly of calcium titanate — which they say has the strongest potential among other emerging compounds. Hybrid perovskites can be synthesized and grown via solution over several hours to a couple of days, compared to conventional sensors that take weeks or months to grow.
Furthermore, once their stability is improved, their cost efficiency, yield, and output rate will put these compounds at the forefront of room temperature semiconductor detector research.
Radiation sensors must be updated to avoid nuclear terrorism and acquisition and use of weapons of mass destruction.
“Preventing radioactive materials from being used for harmful purposes is a global nuclear security challenge,” Johns said. “Equipping law enforcement and first responders with the best possible radiation detectors is key to detecting, identifying and, ultimately, prohibiting radioactive threats.”
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