The University of Tokyo is conducting an investigation into a major accident that occurred Monday at its Super-Kamiokande cosmic ray research facility in Gifu Prefecture, where the groundbreaking discovery that neutrinos have mass was made in 1998.
At least half of the cylinder-shaped neutrino detector's 11,000 photomultiplier tubes (PMTs) were broken Monday when loud noise and strong vibrations racked the huge, water-filled tank, dealing a major setback to research in particle physics worldwide.
Motohiko Yoshimura, director of the Institute for Cosmic Ray Research (ICRR) in the town of Kamioka, said Tuesday he suspects the tank now has a leak.