Welcome to the incredible + surreal Super-Kamiokande at the Kamioka Observatory, Institute for Cosmic Ray Research(ICRR), University of Tokyo. This thing is like a cross between something out of Event Horizon, Sunshine, + Evangelion – and so I kind of love it. The purpose of the project is 3-fold : Cosmic Ray Physics, Experimental Inspection of the Grand Unified Theories, + the Research of Dark Matter – basically their trying to find out what makes the universe tick.
The detector consists of an inner volume and an outer volume which contain 32,000 tons and 18,000 tons of pure water respectively. The outer detector is used to veto entering cosmic ray muons and is used as a buffer to keep radiation emitted by the surrounding rock and walls from entering the inner volume. The inner detector has 11,200 photomultiplier tubes (PMTs) attached to the bottom, top and sides facing inward. The PMTs collect the pale blue light called Cerenkov light which is emitted by particles traveling fast as light in the water. By measuring the direction and intensity of this light,information about particle interactions such as neutrino interactions or proton decay can be determined. Compared to Kamiokande, Super-Kamiokande has ten times the volume and twice the density of PMTs. Construction of the detector was completed in 1995 and observation began on April 1, 1996 [via the Super-Kamiokande website].
My ninjas, please – this thing is just incredible to look at, AND its job is to help study the origins of our universe. That’s pretty siiick.
And for the record, the image above does indeed show two guys in a little rubber raft, floating around this thing – and the image below is an engineer below the pool in the bottom of this giant cylinder [the crawlspace shown in the axon above].