[r9etb]

We put detectors in flooded mines to detect particles from the sun. The water provided shielding. Shielding from radiation from inside instead of outside?

The water wasn't shielding. It's part of the detector. As the neutrinos interact with water molecules, they release Cherenkov Radiation. The detectors look for the tell-tale flash of blue or UV light.

If this theory was true, there'd be all sorts of detections. I don't believe there are, though.

[Robert A Cook PE]

The theory is fairly straightforward: Scintillation detector are very, very sensitive - and *\(unshielded) show light flashes for almost every high-energy particle that passes through the detector.

By going deep under many thousands of feet of (non-radioactive) rock, the cosmic rays and background gamma ray are removed from the incoming signal. Neutrinos are also removed, but they don't react very strongly (if at all) with the typical nucleus of most rock, so almost all neutrinos get to the detector and some (not all!) will react.

The physicists running and designing these underground experiment take both into account: how many background rays WILL get through, and how many target rays (particles) DO NOT get through, factoring how many of each kind they expect to react while these particles are passing through.

Problem is, in the past, numbers they find have not been what they expect - so the search continues.

[SunkenCiv]

:') I should have pointed out that this was a bump to an old topic. Sorry.