The kind of neutrinos emitted in nuclear beta decay—namely electron antineutrinos (νe)—are helping scientists implement a diverse range of intriguing applications beyond fundamental particle-physics research. Like all neutrinos, they’re very difficult to detect because they interact so feebly with matter. Nevertheless, they have in recent years begun providing valuable clues about the origin and thermal history of Earth (see PHYSICS TODAY, September 2011, page 14). They are also providing critical information about the fuel cycle in nuclear reactors and, hopefully soon, new insight on heavy-element production in supernovae.
Two kiloton-sized νe detectors are now monitoring Earth’s interior to help geologists determine the abundance and distribution of uranium and thorium—the planet’s principal heat-producing radioactive elements. A third big detector will soon join them (see figure 1). They and much smaller detectors can also monitor nuclear reactors far and near. Under consideration is a next generation...
