Frederick Reines

Born on 16 March 1918 in Paterson, New Jersey, Frederick Reines was a Nobel Prize–winning physicist who discovered the neutrino. The son of Russian immigrants, Reines earned his BS and MA at Stevens Institute of Technology in Hoboken, New Jersey, then his PhD in physics at New York University. In 1944 he was recruited by Richard Feynman to work on the Manhattan Project at Los Alamos in New Mexico. While there, Reines collaborated with his colleague Clyde Cowan to conduct a series of experiments to look for neutrinos , wispy particles whose existence was first proposed by Wolfgang Pauli in 1930. Reines and Cowan used a nuclear reactor to produce the theorized particles and a tank filled with water and cadmium chloride to detect them. When neutrinos entered the liquid solution, they occasionally interacted with hydrogen nuclei to create positrons and neutrons. Both of the newly produced particles emitted photons that were then recorded by scintillation detectors; recordings of flashes from both particles represented the unique signature of the neutrino. Reines and Cowan wrote about their 1956 discovery the following year in Physics Today. For his part in the detection of the neutrino, Reines won a share of the 1995 Nobel Prize in Physics . In 1966 Reines accepted a post as founding dean of physical sciences at the new University of California campus at Irvine, where he remained until he retired. His scientific team’s research on neutrinos from supernova 1987A won the Bruno Rossi Prize in 1989 from the American Astronomical Society. Reines passed away in 1998 at age 80. (Photo credit: Los Alamos Photo Laboratory, courtesy AIP Emilio Segrè Visual Archives)

Date in History: 16 March 1918