Neutrino Detectors

The ³⁷Cl neutrino detector is a tank containing 100,000 gallons of perchloroethylene (cleaning fluid) in a cavity 4,850 feet below ground in the Homestake Mine in Lead, S.D.

This experiment has been operating since 1967, but has consistently found only half the neutrinos expected from the Sun.

Two possible resolutions:

• The theory of stellar structure is wrong and the core is not as hot as we think
• The theory of subatomic particles is wrong and neutrinos are not exactly what we think

Super Kamiokande is 50,000 tons of purified water in a tank underneath a mountain. 13,000 light detectors are used to look for radiation produced when a neutrino strikes a nucleus in the water.

The solution to the solar neutrino problem appears to be "neutrino mixing." Electron neutrinos that come out of the core of the Sun have a chance of changing into another form of neutrino that is not detected by our experiments.