(Watchman is a shortening of Water Cherenkov Monitor of Antineutrinos.) Mixed in the water will be the element gadolinium, which will absorb the neutron generated in the collision, emitting a second flash of Cherenkov light. In 1987, several large neutrino detectors detected a few handfuls of neutrinos and antineutrinos from the explosion of a star more than 160,000 light-years away. For neutrino scientists, Watchman will also finance the development of improved technology to record the Cherenkov flashes. These are to be deployed in a second phase of Watchman and then could be used in other neutrino experiments.

Source: New York Times March 27, 2018 21:45 UTC