Fifty thousand tons of ultrapure water in a mine a kilometer underground, ringed by thirteen thousand golden eyes, built to catch a proton dying and instead catching the universe's most evasive particle.
Documented
The tank by the numbers
Super-Kamiokande is a stainless tank 39.3 meters across and 41.4 tall holding 50,000 tons of water, watched by about 13,000 photomultiplier tubes, buried 1,000 meters down in Gifu's Kamioka mine; construction began in 1991 and observation started April 1, 1996. Its predecessor Kamiokande, built 1983, existed to watch for proton decay, the '-nde' in its name; it never saw one, which itself ruled out entire grand-unification models.
Assessment: Documented by the collaboration's own records: the specs, the mission, and the null result that kept paying.
Stories
The day the eyes ate each other
On November 12, 2001, while the tank was being refilled after maintenance, a single photomultiplier tube imploded and its shockwave cracked its neighbors, which imploded in turn: about 6,600 of the 11,000-plus tubes destroyed in one chain reaction. The detector limped back with redistributed tubes, then acrylic shock shields, and was fully restored by 2006.
Assessment: Stories: the most sensitive instrument on Earth was nearly destroyed by a pop, a crack, and physics. One bulb's failure became two-thirds of the detector gone in seconds.
Interesting claims
Failure as founding myth
The proton-decay hunt that built the machine produced nothing; the bycatch, solar neutrinos, a supernova burst, atmospheric oscillations, produced two Nobel Prizes. Big-science instruments are sold on one question and answer another, and the funding documents never predict which.
Assessment: Interesting: the detector's real discovery was that the best use of a perfect instrument is unknowable in advance.
Sources and further reading
Super-Kamiokande official outline: 39.3 m x 41.4 m tank, 50,000 tons, ~13,000 PMTs, 1,000 m underground, observations from April 1, 1996
CERN Courier: the November 12, 2001 chain-reaction implosion of ~6,600 photomultiplier tubes and the acrylic-shield rebuild
Kamiokande's founding purpose: the Kamioka Nucleon Decay Experiment, 1983, and the proton-decay null result that killed entire GUT models
Worth asking
When an instrument fails its founding mission and rewrites physics anyway, was the mission ever the point?