Kamiokande II

neutrino detector

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July 16, 2026

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Kamiokande-II was a large, underground water tank used as a neutrino detector. Located in Japan, it contained 3,000 tons of water and was equipped with photomultiplier tubes to detect faint light. When a neutrino collided with a water molecule, it produced an electron that traveled faster than light in water, generating Cherenkov radiation. This allowed scientists to observe neutrinos from events like Supernova 1987A and those produced by cosmic rays. Crucially, data from Kamiokande-II, and its successor Super-Kamiokande, provided evidence for neutrino oscillations, suggesting that neutrinos have mass, a discovery that earned physicists the Nobel Prize.12

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Koshiba Masatoshi
Called Kamiokande II, it was an enormous water tank surrounded by electronic detectors to sense flashes of light produced when neutrinos interacted with atomic nuclei in water molecules. Koshiba was able to confirm Davis’s results—that the Sun produces neutrinos and that fewer neutrinos were found than…
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Called Kamiokande II, it was an enormous water tank surrounded by electronic detectors to sense flashes of light produced when neutrinos interacted with atomic nuclei in water molecules. Koshiba was able to confirm Davis’s results—that the Sun produces neutrinos and that fewer neutrinos were found than…
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Kajita Takaaki
…where he worked on the Kamiokande-II neutrino experiment, a tank containing 3,000 tons of water located deep underground in the Kamioka mine near Hida. Most neutrinos passed right through the tank, but on rare occasions a neutrino would collide with a water molecule, creating an electron. Those electrons travelled faster…
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…where he worked on the Kamiokande-II neutrino experiment, a tank containing 3,000 tons of water located deep underground in the Kamioka mine near Hida. Most neutrinos passed right through the tank, but on rare occasions a neutrino would collide with a water molecule, creating an electron. Those electrons travelled faster…
Read More