This detector began operating in 1996, more than half a mile underground in a
zinc mine in Kamioka, Japan. Japanese and American scientists erected a huge
tank of water 138 feet tall to hunt for neutrinos. The walls, ceiling, and
floor of the 12.5-million-gallon tank are lined with 11,242 light-sensitive
phototubes. These pick up and measure bluish streaks of light called Cherenkov
radiation, which is left behind as neutrinos travel through the water.
Super-Kamiokande detects neutrinos that nuclear interactions in the sun and
atmosphere produce. In 2001, after several promising discoveries related to
potential neutrino mass, the Super-Kamiokande was crippled when several
thousand of its light detectors exploded. Repairs on the detector should be
completed in 2007.