Reines, Frederick (1918–1998)

US physicist who was awarded the Nobel Prize for Physics in 1995 for experimentally detecting the neutrino, one of the fundamental particles which make up all matter. He shared the award with Martin Perl.

The existence of the neutrino was postulated in 1930 by Austrian physicist Wolfgang Pauli to explain the energy losses that occur during beta decay, a type of radioactivity. However, the experimental detection of the neutrino proved difficult since neutrinos pass easily through solid material.

In the late 1950s Reines and Clyde Cowan detected neutrinos produced by a nuclear reactor at the Savannah River nuclear plant, in the southeastern USA. In the experiment neutrinos produced by the reactor passed through a tank of water. Some of the neutrinos reacted with protons in the water, producing flashes which could be detected by a photomultiplier or ‘electric eye’. Nowadays, neutrinos from space are routinely detected by using underground ‘telescopes’ which are similar to the Reines and Cowan set-up.

Reines was born in Paterson, New Jersey, USA, and gained his doctorate in physics from New York University 1944. He was professor of physics at the University of California.