14 DAY TRIAL // A gamma-ray detector that can identify the presence of nuclear materials is nothing new these days, so researchers from the University of Michigan thought to do something even more advanced, and they created a detector that can also pinpoint and give the exact location and type of gamma rays.
The device is called Polaris and it was presented this week at the International Workshop on Room-Temperature Semiconductor Detectors, held jointly with the 2010 IEEE Nuclear Science Symposium and Medical Imaging Conference in Knoxville, Tennessee.
Polaris contains 18 cubes of the semiconductor cadmium zinc telluride, and each cube measures and records the energy emitted by gamma-ray photons, as well as their 3D positioning, determining the direction each photon comes from.
The detector is connected to a computer that uses the energy information to identify what kind of material emits it, every material appearing in a different color.
The device locates the source by using the photon direction and position information.
Zhong He, a professor in the Department of Nuclear Engineering and Radiological Sciences said that “other gamma ray detectors can tell you perhaps that nuclear materials are near a building, but with our detector, you can know the materials are in room A, or room B, for example.
“This is the first instrument for this purpose that can give you a real-time image of the radiation source.
“Not only can we tell you what material is there, but we can tell you where it is, and you can find it and walk towards it.”
He said that Polaris will also be more convenient and portable to use in the field, unlike the current equipment, because it can operate at room temperature and it does not need to be cooled to -200 degrees Celsius like the high-purity germanium gamma ray detectors.
Gamma rays are high-energy photons, or light particles that are usually emitted by nuclear material that could be used for nuclear weapons.
The research was funded by the Department of Defense's Defense Threat Reduction Agency, the Department of Energy, and the Domestic Nuclear Detection Office of the Department of Homeland Security.
Watch the video presentation of the device: