S-1 Uranium Committee
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The S-1 Uranium Committee was a Committee of the National Defense Research Committee (NDRC) that superseded the Briggs Advisory Committee on Uranium and later evolved into the Manhattan Project.
World War II begins
See also:World War II began with the German invasion of Poland on September 1, 1939, prompting Albert Einstein and Leo Szilárd to complete the letter to US President Franklin Delano Roosevelt they had been working on over the summer. Einstein signed the Einstein-Szilárd letter August 1, and it was hand delivered to Roosevelt by the economist Alexander Sachs on October 11, 1939. The letter advised Roosevelt that it was likely the Germans were working on an atomic bomb using uranium, and that the US should be concerned about locating sources of uranium as well as learning how to build such a bomb. At this time the US policy was neutral in the war and Roosevelt did not wish to favor either England or Germany.
Experiments with the fission of uranium were already going on at universities and research institutes in the United States. Alfred Lee Loomis was supporting Ernest Lawrence at Berkeley Radiation Laboratory and Enrico Fermi at Columbia. Vannevar Bush was also doing similar research at the Carnegie Institution in Washington, D.C.. After the April 29, 1940 American Physical Society Spring Meeting the New York Times reported that conferees argued "the probability of some scientist blowing up a sizable portion of the earth with a tiny bit of uranium." The idea that a uranium-235 fission chain-reaction could be used to make a bomb was rapidly becoming every day conversation.
The Briggs Advisory Committee on Uranium
As a result of the letter Roosevelt asked the director of the National Bureau of Standards, Lyman Briggs to secretly organize the Briggs Advisory Committee on Uranium. The Committee's first meeting was on October 21, 1939 in Washington, D.C. and $6,000 was budgeted for conducting neutron experiments conducted by Enrico Fermi and Leo Szilárd at Columbia University.Four aspects of uranium seem to be critical from the start:
- Finding reliable sources of uranium ore in places where the supply cannot be interfered by other countries.
- Developing mass production methods of extracting uranium-235 from ore and/or creating plutonium.
- Making uranium (fission) chain-reaction bombs
- Generating heat from controlled fission to power machines and for creating isotopes.
The MAUD committee
In England two researchers at Birmingham University, Otto Frisch and Rudolf Peierls issued the Frisch-Peierls memorandum in March 1940. The memorandum contradicted the common thinking of the time that many tons of uranium-235 would be needed to make a bomb, so something like a ship would be needed to deliver it. The calculation in the memorandum showed that a bomb might be possible using as little as 1 lb uranium-235, and could be quite practical for aircraft to carry. The researchers' professor Marcus Oliphant passed the memoranda on to Henry Tizard, chairman of the Committee on the Scientific Survey of Air Defence who requested the MAUD Committee be established secretly. The first meeting was on April 10, 1940 and the committee consisted of Sir George Paget Thomson, Chairman, Marcus Oliphant, Patrick Blackett, James Chadwick, Philip Moon and John Cockcroft. Ralph H. Fowler was also asked to send the progress reports to Lyman Briggs in America.The S-1 Uranium Committee
The MAUD Committee completed the MAUD report on July 15, 1941 and disbanded. The report had two parts, the first concluding that a uranium-235 bomb would be feasible using 26 lb. of active metal with a yield equivalent to 1,800 tons of TNT. The second concludes that the controlled fission of uranium-235 could be a source of heat energy for powering machines and a source of radio-isotopes.On April 14, 1941 Lyman Briggs received a note from Eugene Wigner stating:
- ''It may interest you that a colleague of mine who arrived from Berlin via Lisbon a few days ago, brought the following message: a reliable colleague who is working at a technical research laboratory asked him to let us know that a large number of German physicists are working intensively on the problem of the uranium bomb under direction of Heisenberg, that Heisenberg himself tries to delay the work as much as possible, fearing catastrophic results of a success. But he cannot help fulfilling the orders given to him, and if the problem can be solved, it will be solved probably in the near future. So he gave the advice to us to hurry up if U.S.A will not come too late.
In the meantime the NDRC under the leadership of Vannevar Bush was also exploring the possibility of using nuclear energy for power production. A favorable report by Arthur Compton and the National Academy of Sciences was issued May 17, 1941 and after consultation with Roosevelt, Bush created the Office of Scientific Research and Development (OSRD). On July 1, 1941 Bush assumed responsibility for all fission research and the Advisory Committee became the S-1 project of the NDRC with Lyman Briggs reporting to Bush.
Marcus Oliphant came to the United States from England in August 1941 to find out why Briggs and his committee were apparently ignoring the Maud Report. Oliphant discovered to his dismay that the reports and other documents send directly to Briggs had not been shared with the Advisory Committee. Oliphant then met with the Uranium Committee and his colleagues Ernest Lawrence, James Conant and Enrico Fermi to explain the urgency. In these meetings Oliphant spoke of a "bomb" with certainty and explained that Britain did not have the resources to undertake the project so it was up to the United States.
The S-1 project
On December 6, 1941 Vannevar Bush held a meeting to organize an accelerated uranium-235 research project managed by Arthur Compton, with Harold Urey researching gaseous diffusion for uranium enrichment and Ernest Lawrence to research electromagnetic enrichment techniques. One day later the Japanese attack Pearl Harbor and four days after that Germany declared war on the United States. The United States can no longer remain neutral in the war, and begins to mobilize. On December 18, 1941 a meeting is held where the S-1 project is dedicated to development of a uranium bomb.
As a result of the [MAUD report] the British had started a uranium bomb program referred to as the Tube Alloys program. Perceived slowness on the part of the United States had become a contentious issue between US and British scientists. Upon entry into the war, the US placed increasing importance on working cooperatively with the British program. Roosevelt wrote a note to Winston Churchill outline increased US-UK cooperation, but was rebuffed by Churchill. Apparently the British felt the US could add little to the effort at that point. This rebuff turned out to be a major blunder as the US effort quickly caught up with the British effort, and the British realised that their pioneering effort would have no value if it were not quickly capitalized. Leadership of the uranium bomb project in the US had eventually switched to General Leslie R. Groves, who in his own words had never trusted the British (or anyone else).
On June 17, 1942, Roosevelt approved a proposal by Bush to dissolve the original S-1 Section and created the S-1 Executive Committee, chaired by James B. Conant, with the membership of Briggs, Compton, Urey, Lawrence, and Edgar Murphee. The program entered into increased cooperation between the OSRD and the U.S. Army.
On August 13, 1942 the Manhattan Engineering District was created by the Army Corps of Engineers, and on September 17, 1942, command of the district is given to Groves. The S-1 Executive Committee creates two more sites; Site X which becomes the Oak Ridge laboratorywhere methods of uranium-235 separation were developed, and Site Y, a secret laboratory which was located in Los Alamos, New Mexico and put under the direction of Robert Oppenheimer to coordinate bomb research.
As the Army role in the project grew larger, the role of the OSRD became more advisory. Eventually, in May 1943, the Army took full control over the OSRD's research and development contracts, and as such the S-1 Executive Committee became essentially inactive though never formally dissolved. Bush, Conant, and other OSRD insiders continued their influence in the Manhattan Project through their participation in the Military Policy Committee.
References and external links
- Jennet Conant, Tuxedo Park, Simon and Schuster (Apr 29, 2003) ISBN 0684872889
- Thomas Powers, Heisenberg's War, Da Capo Press (Jul 17, 2000) ISBN 0306810115
- Ferenc Morton Szasz, British Scientists and the Manhattan Project, Palgrave (Apr 15, 1992), ISBN 0312061676
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