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Time Periods

1890s-1939:
Atomic Discoveries

1939-1942:
Early
Government Support

1942:
Difficult
Choices

1942-1944:
The Uranium
Path to
the Bomb

1942-1944:
The Plutonium
Path to
the Bomb

1942-1945:
Bringing It All Together

1945:
Dawn of the
Atomic Era

1945-present:
Postscript --
The Nuclear Age


REORGANIZATION AND ACCELERATION
(1940-1941)
Events > Early Government Support, 1939-1942

Ernest Lawrence, 1935During 1939 and 1940, most of the work done on uranium isotope separation and the chain reaction pile was performed in university laboratories by academic scientists funded primarily by private foundations.  Although the federal government began supporting uranium research in 1940, the pace appeared too leisurely to the scientific community and failed to convince scientists that their work was of high priority.  Certainly few were more inclined to this view than Ernest O. Lawrence (right), director of the Radiation Laboratory at the University of California, Berkeley. Lawrence was among those who thought that it was merely a matter of time before the United States was drawn into World War II, and he wanted the government to mobilize its scientific forces as rapidly as possible.

Early in 1941, Lawrence began to toy with another idea, using the electromagnetic method to separate the uranium-235 isotope, which made action seem all the more important. He proposed converting his smaller, thirty-seven-inch cyclotron into a super mass spectrograph to produce uranium-235. Alfred O. C. Nier of the University of Minnesota had been using a mass spectrometer (spectrograph) to prepare small samples of partially separated uranium-235. The mass spectrograph depended on the principle that the lighter particles, uranium-235, in a high-speed beam of ions –- positively charged particles –- were deflected to a greater degree than the heavier ones, uranium-238, as they passed through a magnetic field. Since both Lawrence’s cyclotron and the spectrograph used a vacuum chamber and electromagnet, conversion from one to the other would be relatively uncomplicated. (He later named the result a "calutron.") Lawrence thought that this would open the way to separate larger, purer samples of uranium-235 for study and, eventually, to derive the lighter isotope on a large scale.

Mass-spectrograph components in a 37-inch cyclotron tank, November 1941.Lawrence, demonstrating his characteristic energy and impatience, launched a campaign to speed up uranium research. Lawrence took his case to Karl T. Compton and Alfred L. Loomis at Harvard University, both doing radar work for the National Defense Research Committee and benefiting from Lawrence's advice in staffing their laboratories. Infected by Lawrence's enthusiasm, Compton forwarded Lawrence's optimistic assessment on uranium research to Vannevar Bush, warning that Germany was undoubtedly making progress and that Lyman J. Briggs and the uranium committee were moving too slowly. Compton also noted that the British were ahead of their American colleagues, even though, in his opinion, they were inferior in both numbers and ability.

Vannevar Bush and Arthur Compton, 1940Bush and Lawrence met in New York City.  Though he continued to support the Uranium Committee, Bush recognized that Lawrence's assessment was not far off the mark.  Bush shrewdly decided to appoint Lawrence as an advisor to Briggs -- a move that quickly resulted in funding for plutonium work at Berkeley and for Alfred Nier's mass spectrograph at Minnesota -- and also asked the National Academy of Sciences to review the uranium research program.  Headed by Arthur Compton of the University of Chicago and including Lawrence, this committee submitted its unanimous report on May 17, 1941.  Compton's committee, however, failed to provide the practical-minded Bush with the evidence he needed that uranium research would pay off in the event the United States went to war in the near future.  Compton's group thought that increased uranium funding could produce radioactive material that could be dropped on an enemy by 1943, a pile that could power naval vessels in three or four years, and a bomb of enormous power at an indeterminate point, but certainly not before 1945.  Compton's report discussed bomb production only in connection with slow neutrons, a clear indication that much more scientific work remained to be done before an explosive device could be detonated.  

Bush reconstituted the National Academy of Sciences committee and instructed it to assess the recommendations contained in the first report from an engineering standpoint.  On July 11, the second committee endorsed the first report and supported continuation of isotope separation work and pile research for scientific reasons, though it admitted that it could promise no immediate applications.  The second report, like the first, was a disappointing document from Bush's point of view.

By the time Bush received the second National Academy of Sciences report, he had assumed the position of director of the newly-created Office of Scientific Research and Development(OSRD).  The Uranium Committee became the OSRD Section on Uranium and was codenamed S-1. The National Defense Research Committee, now headed by James B. Conant, president of Harvard University, became an advisory body responsible for making research and development recommendations to the OSRD.

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Sources and notes for this page.

The text for this page was adapted from, and portions were taken directly from the Office of History and Heritage Resources publications: F. G. Gosling, The Manhattan Project: Making the Atomic Bomb (DOE/MA-0001; Washington: History Division, Department of Energy, January 1999), 7-9, and Richard G. Hewlett and Oscar E. Anderson, Jr., The New World, 1939-1946: Volume I, A History of the United States Atomic Energy Commission (Washington: U.S. Atomic Energy Commission, 1972), 33-36. For more on the two National Academy of Sciences reports, see Hewlett and Anderson, Jr., The New World, 1939-1946, 37, 39. The photographs of Ernest Lawrence, and of Vannevar Bush and Arthur Compton are courtesy the Lawrence Berkeley National Laboratory.  The mass spectrograph diagram is reproduced from Gosling, The Manhattan Project, 7; the caption is from Hewlett and Anderson, The New World, 1939-1946, 57.

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