British Mission¹

By 1940, British scientists believed a uranium bomb was feasible. Research by Rudolf Peierls and Otto Frisch theoretically proved that a chain reaction might be sustained using uranium-235. The work of Peierls and Frisch resulted in the establishment of the Committee for the Scientific Survey of Air Warfare, soon to be known as the MAUD Committee. The MAUD Committee completed a pair of reports in the Summer of 1941 entitled "Use of Uranium for a Bomb" and "Use of Uranium as a Source of Power."

The Frisch-Peierls Memo

The 1939 discovery of fission evoked similar, but extremely limited reactions in the United States. Albert Einstein’s letter to President Roosevelt resulted only in the establishment of a basic reactor research program. In late 1940, the British sent a group to the US to offer information on the United Kingdom's atomic project. By then, the United Kingdom had been at war with Germany for more than a year. Their desperate struggle to fend off Hitler’s aerial armadas and the completion of the Frisch-Peierls memorandum gave a sense of urgency to the British atomic program that was not shared by America, which was still at peace. The British contingent, headed by Sir Henry Tizard and Professor J.D. Cockcroft, discovered the US had a similar atomic program, though it was not as well-organized. The visit laid the groundwork for future cooperation between the two nations.

The MAUD Reports

The British furnished Lyman J. Briggs, chairman of the American Uranium Advisory Committee, with a copy of the MAUD reports, but Briggs kept the reports literally under lock and key. Upon discovering the reports, Vannevar Bush, the National Defense Research Committee (NDRC) chairman, commissioned a study on its findings by the National Academy of Sciences (NAS). Though far less optimistic than the British, the NAS endorsed the MAUD report’s basic conclusions. Bush’s endorsement of the MAUD report provided the necessary catalyst to accelerate the atomic program in the U.S.

The Quebec Agereement

Even after America entered the war, cooperation with the British on atomic matters remained sporadic. Though the MAUD reports demonstrated British competency in atomic science, many U.S. officials, such as Manhattan Project leader General Leslie R. Groves, saw little value in collaboration. Although the British could offer the services of skilled scientists, Groves believed they did not bring any vital or original knowledge to the project. When President Roosevelt and British Prime Minister Winston Churchill forged the Quebec Agreement in August 1942, the pact ensured that the United Kingdom and the United States would cooperate on atomic bomb research and production. Immediately following the accord, the British assembled a team of scientists to send to Los Alamos.

The British Mission Arrives in Los Alamos

Sir James Chadwick was appointed leader of the British Mission. He, along with Peierls and the Australian physicist M.L.E. Oliphant, arrived in America in late 1943 and began making preparations for the larger contingent of scientists to follow. Nineteen British scientists ultimately ended up at Los Alamos, including Peierls, who assumed responsibility for implosion research. Otto Frisch, a German expatriate, led the team responsible for first demonstrating the critical mass of uranium-235. Perhaps the important British contribution came from James Tuck, who suggested using explosive lenses in the assembly of the implosion bomb. The British also brought with them Klaus Fuchs, a German Communist, who provided detailed information to the Soviets.

A Great Constribution

The British contribution to the Manhattan Project cannot be overlooked. These scientists served diligently at Los Alamos throughout the war, and some even remained after its conclusion. Hans Bethe, chief of the Theory Division, stated:

"For the work of the Theoretical Division of the Los Alamos Project during the war the collaboration of the British Mission was absolutely essential. . . It is very difficult to say what would have happened under different conditions. However, at least, the work of the Theoretical Division would have been very much more difficult and very much less effective without the members of the British Mission, and it is not unlikely that our final weapon would have been considerably less efficient in this case."

Although General Groves consistently lauded the efforts of the British, he was always quick to add that the US would have produced an atomic bomb without British assistance. In addition their valuable technical contributions, the British also offered many intangibles to the project. The diverse array of scientists - to Germans, Poles, and Brits - gave the project a larger sense of purpose. Even more critical, the European contingent offered new insights from a different perspective. The international nature of scientific research, so crucial to the field of physics in particular, had been desperately lacking since war broke out. The arrival of the British hearkened back to an era of excitement and free exchange. This indispensable contribution, so often overlooked, will remain the lasting legacy of the British Mission.

¹ Based on Dennis C. Fakley’s article, "The British Mission," from Los Alamos Science 40th Anniversary Edition.