Raymond Davis, Jr.
Raymond Davis Jr. ( born October 14, 1914 in Washington, DC; † 31 May 2006 Blue Point, New York) was an American chemist who in 2002 with the Nobel Prize in Physics " for pioneering contributions to astrophysics, in particular was awarded for the detection of cosmic neutrinos ".
Life
Raymond Davis was the son of a photographer and his wife Ida Rogers Younger on 14 October 1914 in Washington DC born. Through the influence of his father, who worked at the National Institute of Standards and Technology and later Head of Photographic technique was, though he had not finished high school, he began early to develop their own experiments and equipment.
After attending public schools in Washington, he completed his studies in chemistry at the University of Maryland in 1938 with a diploma. After a year at Dow Chemical in Midland, Michigan, he returned to the University of Maryland, 1942, he received his doctorate from Yale University in Physical Chemistry and entered as a reserve officer in the army. He spent the following years, especially in the Dugway Proving Ground in Utah with the observation of tests with chemical weapons. After his discharge from the Army in 1945, he worked at Monsanto Chemical in Miamisburg (Ohio ) on radiochemical methods which were for the Atomic Energy Commission of interest. In the spring of 1948 he went to Brookhaven National Laboratory ( BNL ), which had been re-established for the development of civil applications of nuclear energy. There he met his wife Anna Torrey, who was employed in the biology department of BNL, the two were married the end of 1948. They have five children, Andrew, Martha Kumler, Nancy Klemm, Roger and Alan. He said goodbye to 1984 of BNL and was a professor at the Department of Physics and Astronomy of the University of Pennsylvania in Philadelphia.
Work
Davis got the BNL assigned a specific job, but he was able to choose an area of his choice - he chose the neutrino physics. Neutrinos existed at that time only as a theoretical postulate, experimental work, there was not - it was thus an ideal field to bring his experience in radiochemistry.
His first experiment was the realization of an idea by Bruno Pontecorvo in 1946 for the detection of the resulting in a nuclear reactor neutrinos with the reaction 37Cl ν → 37AR e To this end, he built at the research reactor of the BNL a 1000 -gallon tank with carbon tetrachloride, 1955 in the vicinity of a larger reactor in the Savannah River Site. These experiments went negative. Later it turned out that the favored at this time postulate the identity of neutrinos and antineutrinos was wrong - it could therefore succeed no proof, since antineutrinos are produced in the reactor, while the detection reaction is sensitive to neutrinos. It is worth noting, however, that Davis had reached a 20 -fold higher sensitivity for the neutrino flux as it constitutes an experimental proof of the reactor neutrinos by Frederick Reines, who for the Nobel Prize in Physics 1995 was awarded, and Clyde L. Cowan were necessary in 1956.
Following the Savannah experiments he turned to the problem of solar neutrinos, a theme that would occupy him throughout his life. To this end, he built a pilot plant in the Barberton Limestone Mine near Akron, Ohio. In the 1960s he built in the Homestake Gold Mine in Lead (South Dakota), South Dakota, about 1400 meters depth a 100,000 -gallon tank with perchlorethylene. Although the first measurements were fruitless, he refined the measurement techniques so far that he was able to demonstrate solar neutrinos in 1970 for the first time. However, the measured flux was only about a third of postulated by John N. Bahcall river - the solar neutrino problem should for years to deal with the theorists and experimentalists and to be solved by the discovery of neutrino oscillations.
Appreciation
Davis was a life-long single fighter who has set by his work, the foundations of modern neutrino physics. He achieved less through its results, than by his uncompromising struggle to measure the " unmeasurable ". He convinced the experts, by the demonstration of a reliable measurability also of reaction rates with few events per month. Only through his measurements also won other researchers confidence in the feasibility and designed experiments such as SNO, GALLEX and Super Kamiokande. Thus, the gate could be opened to a "new " physics beyond the accepted standard model.
For his achievements he was awarded in 2002 with Masatoshi Koshiba with half of the Nobel Prize in physics, the other half went to Riccardo Giacconi.
Davis was at the time of the award 88 years old, making it the hitherto oldest person who has ever received a Nobel Prize.
Awards
- Boris Pregel Award, New York Academy of Sciences ( NYAS ), 1957
- Comstock Prize in Physics, United States National Academy of Sciences (NAS ), 1978
- Tom W. Bonner Prize for Nuclear Physics, American Physical Society (APS ), 1988
- Honorary Doctorate, University of Pennsylvania ( Penn ), 1990
- Panofsky Prize, American Physical Society (APS ), 1992
- Beatrice M. Tinsley - Prize, American Astronomical Society (AAS ), 1995
- George Ellery Hale Prize, American Astronomical Society (AAS ), 1996
- Honorary Doctorate, Laurentian University, 1997
- Bruno Pontecorvo Prize, Joint Institute for Nuclear Research ( JINR ), Dubna, 1999
- Wolf Prize, Wolf Foundation, 2000
- Honorary Doctorate, University of Chicago, 2000
- National Medal of Science, 2001
- Nobel Prize in Physics, 2002