September, 1941
Enrico Fermi muses to Edward Teller whether a fission explosion could ignite a fusion reaction in deuterium. After some study, Teller concludes that it is impossible.
Enrico Fermi muses to Edward Teller whether a fission explosion could ignite a fusion reaction in deuterium. After some study, Teller concludes that it is impossible.
Enrico Fermi and his team at Manhattan, NY begin assembling a subcritical experimental pile containing 30 tons of graphite and 8 tons of uranium oxide. It gives a projected k value of 0.83, indicating that purer materials are needed.
The MAUD Committee approves its final report and disbands. The report describes atomic bombs in some technical detail, provides specific proposals for developing them, and includes cost estimates. Although the contents of The MAUD Report reach Vannevar Bush at The Office of Scientific Research and Development immediately, he decides to wait for the report to be transmitted officially before taking any further action on fission development. In short, the report concludes that an atomic bomb is indeed feasible.
Emilio Segre and Glenn Seaborg measure the fast fission cross-section of plutonium-239, finding a high value.
The Office of Scientific Research and Development (OSRD) is established. Vannevar Bush is put in charge.
Nazi Germany invades the Soviet Union.
Emilio Segre and Glenn Seaborg determine that the slow cross-section of plutonium-239 is 170% of that of uranium-235, proving it to be an even better prospect for a nuclear explosive.
Tokutaro Hagiwara at the University of Kyoto delivers a speech in which he discusses the possibility of a fusion explosion being ignited by an atomic bomb, apparently the first such mention.
After months of growing pressure from scientists in Britain and the U.S. (particularly University of California at Berkeley's Ernest O. Lawrence), Vannevar Bush at The National Defense Research Committee decides to review the prospects of nuclear energy further and engages Arthur H. Compton and the National Academy of Sciences for the task. The report is issued May 17 and treats military prospects favorably for power production, but does not address the design or manufacture of a bomb in any detail.
Joseph Kennedy, Glenn Seaborg and Emilio Segre show that the plutonium sample undergoes slow fission, which implies it is a potential bomb material.