Raymond Davis, Jr., research professor of physics, is a winner of the 2002 Nobel Prize in physics, the Nobel Foundation, sharing the honor with Masatoshi Koshiba of the University of Tokyo and Riccardo Giacconi of Associated Universities Inc. in Washington.
The Nobel Prize to Dr. Davis and Dr. Koshiba was awarded in recognition of their ground-breaking research into the emission of neutrinos produced by nuclear fusion reactions in the center of the sun. The observation of these neutrinos demonstrated conclusively that the sun is powered by the fusion of hydrogen nuclei into helium nuclei.
Starting in 1967, Dr. Davis detected solar neutrinos by observing the neutrino-induced conversion of chlorine atoms into argon atoms. The observed rate was one argon atom produced every two days in a 615-ton neutrino detector Dr. Davis constructed a mile underground in the Homestake Gold Mine in Lead, S.D. The subterranean location served to screen out cosmic radiation that would otherwise produce too many distracting signals. Since neutrinos rarely interact with matter, they passed easily through the Earth to reach the detector, essentially a 100,000-gallon tank filled with perchloroethylene, a common, chlorine-rich dry cleaning fluid that could be manufactured cheaply in large quantities.
The number of neutrinos Dr. Davis detected reaching the Earth was only one-third that predicted by detailed models of nuclear reactions within the sun. One of the explanations for this discrepancy was that some electron neutrinos produced in solar fusion reactions convert into other neutrino species--specifically, muon and tau neutrinos--during the eight-minute flight from the solar core to the Earth.
Dr. Davis was born in 1917 and received a B.S. in 1937 and an M.S. in 1939, both from the University of Maryland. In 1942 he earned a Ph.D. from Yale University. He served in the U.S. Army during World War II and worked at Monsanto Chemical Company for two years before joining Brookhaven National Laboratory in 1948. At Brookhaven, he served as a research collaborator in chemistry for 37 years, from 1948-1985. Since 1985, he has been a research professor at the University of Pennsylvania. In addition to the Nobel Prize, Dr. Davis also received the 2001 National Medal of Science from President George W. Bush and is also a member of the National Academy of Sciences and the American Academy of Arts and Sciences. Dr. Davis is a resident of Blue Point, N.Y.15, 1988, Dr. Damadian received the National Medal of Technology, the nation's highest honor in technology, presented by President Ronald Reagan, and was inducted into the National inventors Hall of Fame of the U.S. Patent Office in 1989., He is also a member of the National Medal of Technology Foundation, Biophysical Society, and International Society for Magnetic Resonance in Medicine. His other honors include a National Engineer's Special Recognition Award for the Father of MRI Scanning, the Lawrence Sperry Award, Sweden's Olle Olson Award for Radiology, a Montpelier Medal, and teh ellis island Medal of Honor.