IMB
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IMB is an acronym for a neutrino observatory once located in salt mine on the shore of Lake Erie. It was run by a group of American institutions headed by the University of California at Irvine, the University of Michigan, and the Brookhaven National Laboratory (hence the acronym).
IMB consisted of a roughly cubical tank about 20 meters on a side, full of ultrapure water which was surrounded by 2,048 photomultiplier tubes. IMB detected neutrinos by picking up the Cerenkov radiation generated when a neutrino collides with either a proton or an electron (both of which are plentiful in water) and was thus able to estimate the direction of the neutrino by analysing the spatial arrangement of the tubes that detected visible radiation.
The efficiency of IMB was quite low: if 100 trillion neutrinos pass through the detector, on average only one will be detected. This was not so much a reflection of the nature of the device's sensitivity (which was quite high), but rather the "aloof" nature of the largely non-interacting neutrino itself, which is only capable of interacting with normal matter via the electroweak force and gravity.
IMB is famous for having detected 8 of the <math>10^{58}<math> neutrinos emitted by Supernova 1987a.