Cowan–Reines Neutrino Experiment

Discovered by: Clyde Cowan and Frederick Reines. Cowan died in 1974 and Reines was honored with the 1995 Nobel Prize for his work on neutrino physics.

What is it? The experiment exploited a huge flux of (hypothetical) electron antineutrinos emanating from a nearby nuclear reactor and a detector consisting of large tanks of water. Neutrino interactions with the protons of the water were observed, verifying the existence and basic properties of this particle for the first time.

Why is it important? Neutrinos are extremely difficult to detect as they barely interact with matter. In the vicinity of the Earth, about 65 billion solar neutrinos per second pass through every square centimetre perpendicular to the direction of the Sun.