Share A radiation portal monitor screens a truck at Jersey City, New Jersey’s docks. Stephen Chernin/Getty Images New type of imager could help spot smuggled nuclear materials May. 19, 2021 , 2:00 PM Much as a smoke detector gives only a vague idea of where a fire is, current methods to detect smuggled nuclear materials are slow and imprecise. But a new technique that images nuclear materials based on the neutrons and gamma rays they shed can locate these dangers in record time, scientists report. “It’s an elegant method,” says Alexander Glaser, a physicist at Princeton University who works on nuclear weapons verification and was not involved with the new study. If it proves itself in real-world scenarios, he says, the new approach could strengthen border security and help map radioactive contamination at disaster sites like Chernobyl and Fukushima.