Special nuclear materials---the plutonium and uranium that are the main ingredients in nuclear weapons---aren't easy to detect and then find. But a new tool created by engineering professor Zhong He could give an inspector gamma-ray vision, allowing him to see the precise location of any dangerous nuclear materials.
Gamma rays are high energy photons that special nuclear materials emit. The gamma ray detectors used today can only tell you that there's more radiation in a particular area. They can't tell you where it's coming from.
He's new detector, called Polaris, is the first to give a real-time image of gamma ray emissions, so it could lead an inspector directly to any special nuclear materials giving off high concentrations. The research has received millions in government funding. It's being tested right now by the Department of Defense.
Polaris has, for the first time, allowed humans to actually see the Earth's natural background radiation, He says: "We can see radiation from building concrete wall, which is higher intensity than gamma rays emitted in the air, for example."
Another nice thing about it is that it works at room temperature. Today's typical gamma ray detectors have to be cooled to a frosty -200 degrees Celsius to work. That makes them kind of cumbersome to use in the field.
He is a professor in the University of Michigan Department of Nuclear Engineering and Radiological Sciences. He is working on this technology with Ph.D. students Chris Wahl and Weiyi Wang. Here's the whole press release.