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John R. Dunning (Manhattan Project, Key Role in Building A-Bomb)- TLS from 1961
$ 158.4
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TLS on Columbia University letterhead from 1961 complying with an autograph request signed in black fountain pen ink by John R. Dunning.(1907-1975) John Ray Dunning was an American physicist who played key roles in the Manhattan Project that developed the first atomic bombs. He specialized in neutron physics, and did pioneering work in gaseous diffusion for isotope separation. He was Dean of the School of Engineering and Applied Science at Columbia University from 1950 to 1969.
After gaining his doctorate at Columbia, Dunning continued teaching and research there, becoming an assistant professor in 1935, and an associate professor there in 1938. Dunning was a central figure at Columbia on neutron research, and went on to publish 24 papers on neutrons between 1934 and 1938. In 1936, Dunning received a Traveling Fellowship, which he used to meet and discuss his neutron physics research with many eminent European nuclear physicists including Niels Bohr, James Chadwick, Fermi, Werner Heisenberg, and Ernest Rutherford.
Dunning closely followed the work of Ernest Lawrence on the cyclotron. Dunning wanted a more powerful neutron source and the cyclotron appeared as an attractive tool to achieve this end. Government funding was not available for such projects in those days, and university budgets were tight. Nonetheless, during 1935 and 1936 he was able construct a cyclotron using many salvaged parts to reduce costs and funding from industrial and private donations. It was announced in 2007 that Columbia University has decided to junk a 70-year-old atom smasher, which is the nation's oldest artefact of the nuclear era. After being decommissioned in 1965, the machine sat in the basement of Pupin Hall, home of Columbia's physics department. It was scrapped in 2008, although some components are in the Smithsonian Institution in Washington, DC.
In December 1938, the German chemists Otto Hahn and Fritz Strassmann sent a manuscript to Naturwissenschaften reporting they had detected the element barium after bombarding uranium with neutrons. They communicated these results to Lise Meitner, who, with her nephew Otto Frisch, correctly interpreted these results as being the result of nuclear fission. Frisch then confirmed this experimentally on January 13, 1939. Even before it was published, Meitner’s and Frisch’s interpretation of the work of Hahn and Strassmann crossed the Atlantic Ocean with Niels Bohr, who was to lecture at Princeton University. Isidor Isaac Rabi and Willis Lamb, two Columbia University physicists working at Princeton, heard the news and carried it back to Columbia. Rabi said he told Fermi; Fermi gave credit to Lamb. It was soon clear to a number of scientists at Columbia that they should try to detect the energy released in the nuclear fission of uranium from neutron bombardment. On 25 January 1939, Dunning was a member of the Columbia team that conducted the first nuclear fission experiment in the United States. The Other members of the team were Herbert L. Anderson, Eugene T. Booth, Enrico Fermi, G. Norris Glasoe, and Francis G. Slack.
Bohr argued that it was the uranium-235 isotope that was responsible for fission. Dunning realized that if this was the case, then an atomic bomb would be possible. His thoughts turned to devising a process for uranium enrichment, and by 1940 he was investigating gaseous diffusion, which he felt appeared to be more effective than the electromagnetic method of Alfred Nier and offered the best route to enrichment on an industrial scale. The researchers at Columbia became the Manhattan Project's Substitute Alloy Materials (SAM) Laboratories. Dunning headed the laboratory division responsible for all aspects of the gaseous diffusion program, including engineering problems, pilot plants and research activities. Four papers co-written with James Rainwater, William W. Havens, Jr., and Chien-Shiung Wu appeared in 1947 and 1948, but much remained classified. Due to the secrecy of this work, Dunning and three of his colleagues were awarded 0,000 each in lieu of patent royalties. For his part, Dunning was awarded the Medal for Merit by President Harry S. Truman. His citation read:
for exceptionally meritorious conduct in the performance of outstanding service to the War Department, in accomplishments involving great responsibility and scientific distinction in connection with the development of the greatest military weapon of all time, the atomic bomb. As a physical researcher, he took a leading part in the initiation of the early phases of the project; then he was in charge of essential research in the SAM Laboratories for the Manhattan Engineer District, Army Service Forces, and then he served as advisor to the contractor for full scale operation of his process. A physicist of national distinction, Dr. Dunning's unselfish and unswerving devotion to duty have contributed significantly to the success of the Atomic Bomb project.
Comes with a full Letter of Authenticity from Todd Mueller Authentics if the item sells for and over.