| Dr. Raymond Davis, Jr. | |
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| Born | October 14, 1914 Washington, D.C., USA |
| Died | May 31, 2006 (aged 91) Blue Point, New York, USA |
| Fields of Study | Chemist, physicist |
| Awards | Boris Pregel Prize, New York Academy of Sciences, 1957 Cyrus B. Comstock Prize, U. S. National Academy of Sciences, 1978 American Chemical Society Award for Nuclear Applications in Chemistry, 1979 Tom W. Bonner Prize, American Physical Society, 1988 Honorary Doctor of Science, University of Pennsylvania, 1990 W. K. H. Panofsky Prize, American Physical Society, 1992 Beatrice M. Tinsley Prize, American Astronomical Society, 1995 George Ellery Hale Prize, American Astronomical Society, 1996 Honorary Doctor of Science, Laurentian University, 1997 Bruno Pontecorvo Prize, Joint Institute for Nuclear Research, Dubna, Russia, 1999 Wolf Prize, 2000 Honorary Doctor of Science, University of Chicago, 2000 U. S. National Medal of Science, 2001 Nobel Prize in Physics, 2002 Enrico Fermi Award, 2003 Franklin Institute Award, 2003 |
THE YEAR WAS 1952. ABOUT ONCE a month Raymond Davis Jr. would load a fifty-five-gallon drum onto a hand truck and out to a manicured lawn less than fifteen feet from the graphite nuclear reactor at the Brookhaven National Laboratory on Long Island, New York. Davis would deposit the tank—filled with carbon tetrachloride (CCl4), an ordinary but toxic cleaning fluid - on the lawn and walk away. There it would rest undisturbed, until Davis returned a few weeks later. He would then reload the drum onto his hand truck, take it back to the chemistry building and run a set of complicated tests on the fluid.
Now, forty-three years later, Ray Davis takes me for a tour of a successor to his fifty-five-gallon drum. I meet him, a soft-spoken, grandfatherly man wearing a hard hat and a miner's lamp, at a vast working gold mine known as Homestake in Lead, South Dakota.
To reach the full-scale experiment you board a mine elevator called the cage, a small, five-by-ten-foot space running on vertical wooden railings and hauled up and down a 4,850-foot shaft with steel cables. The cage shakes and rattles vigorously as it drops deeper than three times the height of the Empire State Building, taking at least three minutes to reach the 4,850-foot level.
Once you exit the elevator you walk about a hundred yards along a mine passageway, with train tracks cut into its rock floor. The faint twinkle of train headlights in the distance makes the length of the passage seem unmeasurable, and the soft, deep rumble of ore being loaded into train cars can always be heard in the background. A right turn at the first intersection quickly takes you beyond the air-conditioning vents, and the temperature rises above eighty degrees Fahrenheit. There in the passage is what seems to be a small chemical laboratory, old personal computers lining one wall, arrays of glass test tubes lining another.
To the left is a side passage, angling steeply downward. At its bottom, about a mile below the surface, is the tank chamber, a room the size of a two-story house, filled with a gray tank nearly forty-eight feet long and more than thirty feet in diameter, which holds 100,000 gallons of the dry-cleaning fluid tetrachloroethylene (C2Cl4). Puddles of muddy, rust-colored water lap at the base of the tank. White and red crystal formations have grown along the edges of the tank in the three decades since its construction. Every other month Ray Davis and his associates come down here to squeeze a minute quantity of argon-37, fifteen atoms on average, out of the tank.
From “The Shadow Boxer” by Robert Zimmerman, published in Sciences 5.
The name Raymond Davis, Jr. will continue to become more familiar to residents of the Black Hills as work on the DUSEL continues and as more work is done at the lab. Dr. Davis was often in the Homestake Mine in the 1960s collecting argon samples. Davis developed an interest in chemistry at an early age and while still a student visited the library to read the Smithsonian Technical Reports 3. After receiving his PhD in 1942, Davis served in the Army Air Corps during the Second World War. In 1948 he began work at the Brookhaven National Laboratory on Long Island, New York. He was a research chemist at Brookhaven until 1984 and created the first working neutrino detector while there. In 1984 he moved to the University of Pennsylvania, where he served as a research professor in astronomy. During this time he was also a research consultant at the Los Alamos National Laboratory in New Mexico.
Davis became very interested in Enrico Fermi’s neutrino theory and determined that, in spite of other scientist’s opinions, neutrinos were able to be detected. According to calculations by Bruno Pontecorvo, a chlorine atom would transform into radioactive argon when hit by a neutrino. Radioactive argon is detectable, and so therefore, are neutrinos 2. Davis experimented in a limestone quarry in Ohio using dry cleaning fluid that contained chlorine and kept in a big tank thinking that cosmic rays would be blocked out, but the quarry wasn’t deep enough. Later in the decade he tried this again in the Homestake Mine – almost a mile underground. He was unable to detect neutrinos there until he synthesized 100 argon atoms, released them into tanks, and extracted them back out.
Davis suffered from Alzheimer's disease for four years before dying of complications of the disease on May 31, 2006, at his home in Blue Point, New York. He was 91. He is survived by his wife, Anna; his sons Andrew, Roger, and Alan; his daughters Martha and Nancy; and eleven grandchildren 2.
Davis has been honored a number of times with awards including the Enrico Fermi award, the National Medal of Science, the Wolff Foundation Prize in Physics, and the Bruno Pontecorvo prize in physics 1.
In 2002, Davis shared the Nobel Prize in Physics with Japanese physicist Masatoshi Koshiba "for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos" 4. At nearly 88 years old, Davis was the oldest person to ever be awarded a Nobel Prize.
