- Person
- Frederick Reines
- Lived
- 1918–1998
- Field
- Neutrino physics
- From
- American
The story
Frederick Reines was born in Paterson, New Jersey, in 1918 to Jewish emigrants from Russia; the founder of religious Zionism, Rabbi Isaac Jacob Reines, was a relative on his father’s side. After a doctorate at New York University he joined the Manhattan Project at Los Alamos in 1944.
In 1930 Wolfgang Pauli had proposed an uncharged, almost massless particle to account for energy that seemed to vanish in radioactive decay. Enrico Fermi named it the neutrino. It interacts so weakly that in 1934 Hans Bethe and Rudolf Peierls concluded there was no practical way to observe it. In 1951 Reines decided to try anyway, because, as he later put it, everybody said you couldn’t do it.
With his Los Alamos colleague Clyde Cowan he designed a detector that would recognise a unique signature. When an antineutrino from a nuclear reactor strikes a proton in a tank of liquid scintillator, it creates a positron and a neutron. The positron annihilates at once, giving a flash of gamma rays; moments later the neutron is captured by cadmium dissolved in the liquid, giving a second flash. Their first attempt, at the Hanford reactor in Washington State in 1953, was swamped by cosmic-ray background. In 1955 they moved to the powerful new Savannah River reactor in South Carolina, placing the detector 11 metres from the core and 12 metres underground. In June 1956 they sent Pauli a telegram announcing that the neutrino had been found.
Reines spent the rest of his career on neutrinos. Cowan died in 1974, and in 1995 Reines received the Nobel Prize in Physics for the detection of the neutrino.
Their detection method lives on. Detectors that catch reactor antineutrinos in the same way have been developed to monitor nuclear reactors from outside: because the antineutrino flow reflects a reactor’s power and fuel, a compact detector operated automatically at the San Onofre plant in California from 2003 to 2006 could track the reactor’s output, an approach studied as a tool for international nuclear safeguards.
Why it matters
Reines and Cowan proved the neutrino was real and gave science a way to catch it, opening neutrino physics and astronomy and leading to detectors that can monitor nuclear reactors from outside.
About Frederick Reines
New Jersey physicist who, with Clyde Cowan, first detected the neutrino, then founded neutrino astronomy; his reactor method now underpins tools to monitor nuclear reactors. Nobel Prize 1995.
More about Frederick Reines
Sources
- Frederick Reines, Biographical NobelPrize.org
- Frederick Reines Wikipedia
- Reactor monitoring and safeguards using antineutrino detectors arXiv (Bowden et al.)
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.