The British Mission by Dennis C. Fakley*

ews of the discovery in early , accompanied by Professor J. basis, and the Directorate of —a 1939 of -induced fission D. Cockcroft, led a mission to Washington. title chosen as a cover name—was formed in immediately The programme was within the Department of Scientific and N prompted ideas in the United described and was found to parallel the Industrial Research under the technical lead- Kingdom and elsewhere not only of a con- United States programme, although the lat- ership of W. A. Akers, recruited from Im- trolled fission chain reaction but also of an ter was being conducted with somewhat less perial Chemical Industries, and the policy uncontrolled, explosive chain reaction. Al- urgency. It was agreed that cooperation guidance of Sir John Anderson, Lord Presi- though official British circles viewed with a between the two countries would be mutually dent of the Council. high degree of skepticism the possible advantageous, and the necessary machinery Meanwhile, in the United States Dr. Van- significance of uranium fission for military was established. Even at this early stage the nevar Bush, head of the National Defense application, some research was initiated at British increasingly recognised that, with Research Committee, had asked the presi- British universities on the theoretical aspects their limited resources, they would have to dent of the National Academy of Sciences in of achieving an explosive reaction. Progress look to the immense production capacity of April 1941 to appoint a committee of was slow, the initial results were discourag- America for the expensive development physicists to review the uranium problem. ing, and, following the outbreak of World work; before long the MAUD Committee This committee, which was given copies of War II, the effort was reduced and resources was discussing the possibility of shifting the the MAUD reports, reached conclusions in were moved to more pressing and more main development work to America. November 1941 which were remarkably promising defence projects. The turning By the Spring of 1941, the MAUD Com- similar to those of the MAUD Committee, point came in March 1940 with the inspired mittee itself was convinced that a bomb was but it was less optimistic about the effective- memorandum by O. R. Frisch and R. E. feasible, that the quantity of uranium-235 ness of a uranium bomb, the time it would Peierls, then both of Birmingham University, required was small, and that a practical take to make one, and the costs. Surpris- in which they predicted that a reasonably method of producing uranium enriched in ingly, despite the discoveries made at small mass of pure uranium-235 would sup- uranium-235 could be developed. It had also Berkeley, the committee did not refer to the port a fast chain reaction and outlined a decided that there were no fundamental possibility of a weapon. On the method by which uranium-235 might be obstacles in the way of designing a uranium basis of the report of the National Academy assembled in a weapon. bomb. However, the possibility of a pluto- of Sciences, President Roosevelt ordered an The importance of the Frisch-Peierls nium bomb had been pushed into the back- all-out development programme under the memorandum was recognised with surpris- ground partly because of doubts about feasi- administration of the newly created Office of ing rapidity, and a uranium subcommittee of bility and partly because large resources Scientific Research and Development and the Committee for the Scientific Survey of appeared to be needed for the development endorsed a complete exchange of informa- Air Warfare was set up. This subcommittee, of a plutonium production route. The British tion with Britain. were unaware of the work on plutonium soon to assume an independent existence as *Assistant Chief Scientific Advisor (Nuclear), the MAUD Committee,** commissioned a already carried out by Professor E. O. Ministry of Defence, . The author is series of theoretical and experimental re- Lawrence at Berkeley. indebted to Professor , Official search programmed at Liverpool, Bir- The MAUD Committee produced two Historian of the United Kingdom Atomic Energy Authority, from whose book Britain and Atomic mingham, Cambridge, and Oxford univer- reports on its work at the end of July 1941. Energy 1939-1945 this outline history has been sities and at Imperial Chemical Industries. These reports, “Use of Uranium for a drawn and to Lord Penney who was kind enough By the end of 1940, nothing had disturbed Bomb” and “Use of Uranium as a Source of to edit the text. the original prediction of Frisch and Peierls Power,” were formally processed through **The story of the choice of title for this commit-- that a bomb was possible, the separation of the Ministry of Aircraft Production, the tee bears retelling. When Denmark was occupied by the Germans, sent a telegram to uranium-235 had been shown to be in- high-level Scientific Advisory Committee, Frisch, who had worked in Bohr’s Copenhagen dustrially feasible, and a route for producing and the Chiefs of Staff to Prime Minister laboratory, asking him at the end of the message plutonium-239 as a potentially valuable Churchill, but, as a result of a great deal of to “tell Cockcroft and Maud Ray . ”Maud Ray Kent was assumed to be a cryptic reference bomb material had been identified. unofficial lobbying, Churchill had made the to or possibly uranium disintegration, and The first official contact between decision that the bomb project should MAUD was chosen as a for the American and British nuclear research fol- proceed before the official recommendations uranium committee. Only after the war was Maud Ray identified as a former governess to Bohr’s lowing the outbreak of the war in Europe reached him. It was recognised that the children who was then living in the county of took place in the Fall of 1940 when Sir project had to be set up on a more formal Kent.

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Although information exchange continued would use the bomb against or disclose it to Oliphant had taken up indefinite residence in until the middle of 1942, the British were a third party without mutual consent, and America. Chadwick was occupied mostly in ambivalent about complete integration of the recognition of the United States’ right to Washington with diplomatic and ad- bomb project and expressed reservations limit whatever postwar commercial advan- ministrative functions but spent some time in which, with hindsight, make strange reading. tages of the project might accrue to Great Los Alamos; Peierls worked initially on By August 1942, when Sir John Anderson Britain. A mission to Washington by but later at Los Alamos; offered written proposals for cooperation Anderson reached agreement on provisions and Oliphant, with three colleagues, worked beyond a mere information exchange, the for establishment of a General Policy Com- at Berkeley with Lawrence’s electromagnetic American project had been transferred from mittee and for renewal of information ex- team; a further two scientists were attached the scientists to the U.S. Army under Gen- change. These provisions together with the to Los Alamos. eral L. R. Groves. Britain was probably no points in the draft agreement were in- The exodus of British scientists to longer regarded by the Americans as being corporated in the , which America accelerated in the early months of able to make any useful contribution, and the was signed by Roosevelt and Churchill on 19 1944. However, those who joined the question of integration was deferred. August 1943. gaseous diffusion programme did not stay Further, the imposition of a rigid security There were still some minor hurdles to be long, and all were withdrawn by the Fall of system by the U.S. Army led to such severe surmounted before the Quebec Agreement 1944. The British team which joined Law- restrictions on the information exchange that could be implemented in detail, but they were rence at Berkeley built up rapidly to about the only real traffic related to the gaseous overcome more rapidly than might have 35 and was completely integrated into the diffusion process for producing enriched been expected by anyone who had ex- American group; most stayed until the end uranium and to the use of as a perienced the difficult days in the first half of of the war. The British team assembled at reactor moderator. 1943. The increased cordiality of Anglo- Los Alamos finally numbered 19,* and, as at The change in the United States’ attitude American relations was due almost entirely Berkeley, the scientists were assigned to toward cooperating with Britain came as a to personal relations built up at the working existing groups in the Laboratory (although great shock to the British. Prime Minister level. Of pre-eminent importance was the not to those groups concerned with the Churchill took up the issue with President rapport established between General Groves preparation of plutonium and its chemistry Roosevelt in early 1943 without any early and Professor , senior tech- and metallurgy). sensible effect. Meanwhile, the British nical adviser to the British members of the The first British scientists to go to Los studied the implications of a wholly inde- Combined Policy Committee. Alamos were mainly nuclear physicists. pendent programme and reached what With the resumption of cooperation, the They included Frisch, who led the Anglo- would now appear to be the self-evident first task was an updating one. The British American group that first demonstrated the conclusion that such a programme could not handed over a pile of reports on the progress of uranium-235, and E. lead to results which could influence the of their work, and General Groves supplied a Bretscher, who found a niche in the group outcome of the war in Europe. copy of the progress report he had just already thinking about fusion weapons. As A breath of fresh air blew over the scene submitted to the President. The British were the team built up, most of the British scien- when Bush, now director of the Office of amazed by the progress made in America tists were allocated to work on implosion Scientific Research and Development, and and staggered by the scale of the American weapon problems and to bomb assembly in U.S. Secretary of War Henry Stimson visited effort: the estimate of the total project cost general. Implosion was considered before the London in July 1943. At a meeting with was already in excess of one thousand British arrived at Los Alamos, but Dr. J. L. Churchill, a number of misunderstandings million dollars compared with the British Tuck made a significant contribution with on both sides were satisfactorily resolved, expenditure in 1943 of only about half a his suggestion of explosive lenses for the and it was agreed that the British should million pounds. Chadwick was in no doubt achievement of highly symmetrical im- draft an agreement defining the terms for that the first duty of the British was to assist plosions. During 1944 Dr. W. G. (now Lord) future collaboration on the bomb project. the Americans with their project and aban- Penney was recruited to assist with the The draft agreement included a statement of don all ideas of a wartime project in Eng- *E. Bretscher, B. Davison, A. P. French, O. R. the necessity for the bomb project to be a land. He concluded that this would best be Frisch, K. Fuchs, J. Hughes, D. J. Littler, W. G. completely joint effort, a pledge that neither achieved by sending British scientists to Marley, D. G. Marshall, P. B. Moon, R. E. country would use the bomb against the work in the United States. Before the end of Peierls, W. G. Penney, G. Placzek, M. J. Poole, J. Rotblat, H. Sheard, T. H. R. Skyrmes, E. W. other, a further pledge that neither country 1943, Chadwick, Peierls, and M. L. E. Titterton, J. L. Tuck.

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Members of the British Mission enter- tained their guests at the celebratory party with a skit depicting the adventures that befell Good Uncle Winnie’s “Babes in the Woods” during their attempt with Good Uncle Franklin’s forces to outwit Bad Uncles Adolph and Benito. At left a devilish security officer (J. L. Tuck) harasses an unhappy scientist (P. B. Moon), who wears his footprint as identi- fication. In the skit’s finale (below) a makeshift tower supports a gadget that was detonated with remarkable sound and light effects. Identifiable are (left to right) Winifred Moon (in pigtails), O. R. Frisch (costumed as an Indian maid), that secur- ity officer again, P. B. Moon (behind the ladder), E. W. Titterton (in background), W. G. Marley, and G. Placzek.

188 Winter/Spring 1983 LOS ALAMOS SCIENCE The British Mission

THE BRITISH MISSION

INVITES YOU TO A PARTY IN CELEBRATION OF

SATURDAY, 22ND SEPTEMBER, 1945 explosive side of the programme, as were Dr. W. G. Marley and two assistants. Eventually six British scientists (Bretscher. Frisch, P. B. Moon, Peierls, Penney, and G. Placzek) PRECEDED BY SUPPER AT 8 P.M. became the heads of joint groups and a seventh, Marley, became head of a section. Further, two highly distinguished consult- R.S.V.P TO MRS. W. F. MOON ants were made available under British aus- Room A-211 ( EXTENSION 250) pices, namely Professor Niels Bohr and Sir Geoffrey Taylor. Bohr’s visits to Los Ala- mos were inspirational; Taylor was able to The social triumph of the collaboration between the British and the Americans on the contribute significantly to the work on was a celebratory party hosted by the British Mission. All aspects hydrodynamics. of the celebration had a properly British flavor: formal invitations, a "footman” to There is no objective way of measuring announce the arrival of the guests, an entree of steak-and-kidney pie, a dessert of the contribution made by the British to the trifle, and the best port for ceremonial toasts to the King, the President, and the Grand Manhattan Project at Los Alamos and elsewhere. General Groves often acknowl- Alliance. edged the importance of the early work in the United Kingdom and the substantial amendment to the 1954 United States Agreement for Mutual Cooperation on the contribution made by her scientists in Atomic Energy Act, the developments in Uses of Atomic Energy for Mutual Defense America, but he added that the United States nuclear weapons technology over the previ- Purposes (as Amended). It is possible to could have got along without them. The ous eleven years were found to be re- identify very many of the same strengths and British presence, though small, certainly had markably similar. weaknesses that were evident in the 1940s. a beneficial effect on the morale It is also of interest to note the similarities Those who have been intimately connected of the Project. It served a function not between the wartime cooperation on the with the collaboration on nuclear defence otherwise available in that closed com- development of the first and subscribe to the view that it works in the munity—as a centre of second opinions by the cooperation which has ensued over the overall joint defence interests of the two scientists whose reputations were generally past 25 years under the 1958 U.S.-U.K. countries. ■ admired. Whatever the variations in the opinions of the British contributions to the Manhattan Project, there is no dispute that their participation benefited the British consider- ably. The course of the British nuclear programme in the postwar period would have been very different had it not been for the wartime collaboration. While United States law prohibited international coopera- tion on , the British were able to undertake a successful inde- pendent nuclear weapons programme, which, despite its small scale relative to that of the American programme, succeeded in elucidating all the essential principles of both fission and thermonuclear warheads and in producing an operational nuclear weapons capability. When the two countries came together again in 1958, following a critical

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