CHICAGO, Jan. 16 (Xinhua) -- Researchers at Northwestern University (NU) and Argonne National Laboratory have developed a new material that opens doors for a new class of neutron detectors.
In a study, the researchers discovered the right combination of materials to make a working device that also keeps lithium stable. The new material, lithium-indium-phosphorous-selenium, is layered in structure and enriched with the lithium-6 isotope.
"The crystal structure is special," said NU's Mercouri Kanatzidis, who led the research. "The lithium is inside the layers, so water cannot reach it. That's a big, important feature of this material."
The resulting semiconductor neutron detector can detect thermal neutrons from even a very weak source and can do so within nanoseconds. It also can discriminate between neutrons and other types of nuclear signals, such as gamma rays, which prevents false alarms.
Furthermore, the material contains a very high amount of lithium. So a smaller fraction of the material can absorb the same amount of neutrons as a giant device. This leads to devices small enough to fit in one's hand.
"It's important to have all sizes of neutron detectors and as many kinds as possible, such as our new semiconductor," Kanatzidis said. "You want ones that are as big as a wall, where you can pass a truck right by it. But you also want small ones that can be portable for inspections out in the field."
Classic types of thermal neutron detectors have been in use since the 1950s. Currently, there are two classes of detectors which either use helium gas or flashes of light. These detectors are very large, sometimes the size of a wall.
The study was published on Thursday in the journal Nature.
