229-572: The Los Alamos Laboratory , also known as Project Y , was a secret laboratory established by the Manhattan Project and operated by the University of California during World War II . Its mission was to design and build the first atomic bombs . Robert Oppenheimer was its first director, serving from 1943 to December 1945, when he was succeeded by Norris Bradbury . In order to enable scientists to freely discuss their work while preserving security,
458-550: A German atomic bomb project would develop one first, especially among scientists who were refugees from Nazi Germany and other fascist countries. In August 1939, Hungarian-born physicists Leo Szilard and Eugene Wigner drafted the Einstein–Szilard letter , which warned of the potential development of "extremely powerful bombs of a new type". It urged the United States to acquire stockpiles of uranium ore and accelerate
687-733: A neutron moderator . The S-1 Committee recommended pursuing all five technologies. This was approved by Bush, Conant, and Brigadier General Wilhelm D. Styer , who had been designated the Army's representative on nuclear matters. Bush and Conant then took the recommendation to the Top Policy Group with a budget proposal for $ 54 million for construction by the United States Army Corps of Engineers , $ 31 million for research and development by OSRD and $ 5 million for contingencies in fiscal year 1943. They sent it on 17 June 1942, to
916-413: A nuclear fusion reaction between deuterium and tritium . Teller proposed scheme after scheme, but Bethe rejected each one. The fusion idea was set aside to concentrate on producing fission bombs. Teller also raised the speculative possibility that an atomic bomb might "ignite" the atmosphere because of a hypothetical fusion reaction of nitrogen nuclei, but Bethe calculated that this could not happen, and
1145-543: A sawmill , ice house , barns , carpentry shop, stables and garages , all totalling 29,560 square feet (2,746 m). At the nearby Anchor Ranch there were four houses and a barn. Construction work was supervised by the Albuquerque Engineer District until 15 March 1944, when the Manhattan Engineer District assumed responsibility. Willard C. Kruger and Associates of Santa Fe, New Mexico ,
1374-607: A AAA rating whenever it was required. Nelson initially balked but quickly caved in when Groves threatened to go to the President. Groves promised not to use the AAA rating unless it was necessary. It soon transpired that for the routine requirements of the project the AAA rating was too high but the AA-3 rating was too low. After a long campaign, Groves finally received AA-1 authority on 1 July 1944. According to Groves, "In Washington you became aware of
1603-516: A chair in 1927. Heisenberg set Peierls a research project on ferromagnetism . It was known that this was caused by the spin of the electrons in the metal aligning; but the reason for this was unknown. Heisenberg suspected that it was caused by a quantum mechanical effect, caused by the Pauli exclusion principle . Peierls was unable to develop the theory, but work on Hall effect was more productive. The anomalous Hall effect could not be explained with
1832-609: A compromise whereby the laboratory was operated by the University of California. Financial and procurement activities were the responsibility of the University of California under a 1 January 1943 letter of intent from the OSRD. This was superseded by a formal contract with the Manhattan District on 20 April 1943, which was backdated to 1 January. Financial operations were directed by the resident business officer, J. A. D. Muncy. The intent
2061-464: A critical mass. The metal needs to travel only a very short distance, so the critical mass is assembled in much less time than it would take with the gun method. At the time, the idea of using explosives in this manner was quite novel. To facilitate the work, a small plant was established at the Anchor Ranch for casting explosive shapes. Throughout 1943, implosion was considered a backup project in case
2290-447: A day. The Provisional Engineer Detachment (PED), 4817th Service Command Unit, was activated at Camp Claiborne, Louisiana , on 10 April 1943. These men performed jobs around the post such as working in the boiler plant, the motor pool and the mess halls. They also maintained the buildings and roads. It reached a peak strength of 465 men, and was disbanded on 1 July 1946. The 1st Provisional Women's Army Auxiliary Corps (WAAC) Detachment
2519-504: A family in Canada. In February and March 1940, Peierls and Frisch co-authored the Frisch–Peierls memorandum , which Peierls typed. This short paper was the first to establish that an atomic bomb could be created from a small amount of fissile uranium-235 . Based on the information at hand, they calculated that less than 1 kg would be required. The true figure for the critical mass
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#17328450124422748-534: A few months; he was succeeded as head of the British Mission by Rudolf Peierls. The original idea, favored by Groves, was that the British scientists would work as a group under Chadwick, who would farm out work to them. This was soon discarded in favor of having the British Mission fully integrated into the laboratory. They worked in most of its divisions, only being excluded from plutonium chemistry and metallurgy. With
2977-707: A fission bomb was theoretically possible. The properties of pure uranium-235 were relatively unknown, as were those of plutonium, which had only been isolated by Glenn Seaborg and his team in February 1941. The scientists at the July 1942 conference envisioned creating plutonium in nuclear reactors where uranium-238 atoms absorbed neutrons that had been emitted from fissioning uranium-235. At this point no reactor had been built, and only tiny quantities of plutonium were available from cyclotrons . Even by December 1943, only two milligrams had been produced. There were many ways of arranging
3206-732: A fission bomb was theoretically possible. There were still many unknown factors. The properties of pure uranium-235 were relatively unknown; even more so those of plutonium , a chemical element that had only recently been discovered by Glenn Seaborg and his team in February 1941, but which was theoretically fissile . The scientists at the Berkeley conference envisioned breeding plutonium in nuclear reactors from uranium-238 atoms that absorbed neutrons from fissioning uranium-235 atoms. At this point no reactor had been built, and only microscopic quantities of plutonium were available that had been produced by cyclotrons . There were many ways of arranging
3435-502: A general expression for diamagnetism in metals at low temperatures. This provided an explanation of the hitherto mysterious properties of bismuth , in which diamagnetic properties were more pronounced than in other metals. Due to Adolf Hitler's rise to power in Germany, he elected to not return home in 1933, but to remain in Britain. He declined an offer from Otto Stern of a position at
3664-467: A great deal of valuable scientific equipment. Wilson's group dismantled the cyclotron at Harvard University and had it shipped to Los Alamos; McKibben's brought two Van de Graaff generators from Wisconsin; and Manley's brought the Cockcroft–Walton accelerator from the University of Illinois . Communications with the outside world went through a single Forest Service line until April 1943, when it
3893-627: A hole in the theory of electrons in solids ". In 1932, Peierls was awarded a Rockefeller Fellowship to study abroad, which he used to study in Rome under Enrico Fermi , and then at the Cavendish Laboratory at the University of Cambridge in England under Ralph H. Fowler . In Rome, Peierls completed two papers on electronic band structure , in which he introduced the Peierls substitution , and derived
4122-856: A liaison office in Washington, D.C., but established his temporary headquarters at 270 Broadway in New York, where he could draw on administrative support from the Corps of Engineers' North Atlantic Division . It was close to the Manhattan office of Stone & Webster , the principal project contractor, and to Columbia University. He had permission to draw on his former command, the Syracuse District, for staff, and he started with Lieutenant Colonel Kenneth Nichols , who became his deputy. Because most of his task involved construction, Marshall worked in cooperation with
4351-768: A lieutenant colonel on 19 January 1943, and was promoted to colonel on 15 February. Los Alamos officially became a military establishment on 1 April 1943, and he moved to Los Alamos on 19 April. He was succeeded by Lieutenant Colonel C. Whitney Ashbridge, a graduate of the Los Alamos Ranch School, in May 1943. In turn, Ashbridge was succeeded by Lieutenant Colonel Gerald R. Tyler in October 1944, Colonel Lyle E. Seaman in November 1945, and Colonel Herb C. Gee in September 1946. The post commander
4580-491: A major contribution to the understanding of the Rayleigh–Taylor instability . This instability at the interface between two fluids of different densities occurs when the lighter fluid is pushing the heavier, and was vital to the interpretation of experiments with explosives, predicting the effects of an explosion, the design of the neutron initiators , and the design of the atomic bomb itself. Chadwick remained only for
4809-477: A meeting called by Stimson, which established a Military Policy Committee, responsible to the Top Policy Group, consisting of Bush (with Conant as an alternate), Styer and Rear Admiral William R. Purnell . Tolman and Conant were later appointed as Groves' scientific advisers. On 19 September, Groves went to Donald Nelson , the chairman of the War Production Board, and asked for broad authority to issue
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#17328450124425038-410: A nuclear reactor was too great due to the presence of plutonium-240 and would cause a predetonation , a nuclear chain reaction before the core was fully assembled. Oppenheimer then reorganized the laboratory and orchestrated an all-out and ultimately successful effort on an alternative design proposed by John von Neumann , an implosion-type nuclear weapon , which was called Fat Man . A variant of
5267-543: A nursing home near Farmoor , Oxfordshire . He liked to read scientific papers in enlarged script on a computer screen. During 1995, his health continued to decline, and he required regular kidney dialysis sessions at Churchill Hospital , where he died on 19 September 1995. Peierls was knighted in the 1968 Birthday Honours . He was awarded the Rutherford Memorial Medal in 1952, the Royal Medal in 1959,
5496-573: A paper on what is now known as the Bohr–Peierls–Placzek relation . The Second World War broke out before it could be published; but drafts were circulated for comment, and it became one of the most cited unpublished papers of all time. After the outbreak of the Second World War in September 1939, Peierls started working on nuclear weapons research with Otto Robert Frisch , a fellow refugee from Germany. Ironically, they were excluded from
5725-457: A paper with Bethe on the neutrino . The University of Manchester awarded him a D.Sc. degree. Moving back to Cambridge, he worked with David Shoenberg at the Mond Laboratory on superconductivity and liquid helium . To allow him to lecture, in accordance with its rules, St John's College, Cambridge , awarded him an ex officio M.A. degree. In 1936, Mark Oliphant was appointed
5954-530: A passport and exit visa. They finally left for Zürich that summer. They had four children: Gaby Ellen (b.1933), Ronald Frank (b.1935), Catherine (Kitty; b.1948), and Joanna (b.1949). Peierls assisted Egon Orowan in understanding the force required to move a dislocation which would be expanded on by Frank Nabarro and called the Peierls–Nabarro force . In 1929, he studied solid-state physics in Zurich under
6183-496: A physicist at the Metallurgical Laboratory, was assigned to assist Oppenheimer by contacting and coordinating experimental physics groups scattered across the country. Oppenheimer and Robert Serber of the University of Illinois examined the problems of neutron diffusion—how neutrons moved in a nuclear chain reaction—and hydrodynamics —how the explosion produced by a chain reaction might behave. To review this work and
6412-572: A plant, much less four of them for $ 90 million." A single TNT plant that Nichols had recently built in Pennsylvania had cost $ 128 million. Nor were they impressed with estimates to the nearest order of magnitude, which Groves compared with telling a caterer to prepare for between ten and a thousand guests. A survey team from Stone & Webster had already scouted a site for the production plants. The War Production Board recommended sites around Knoxville, Tennessee , an isolated area where
6641-455: A plutonium-239 nucleus absorbing a neutron. What had not been suspected was its high spontaneous fission rate. Segrè's group measured it at 1.6 million fissions per gram per hour, compared with just 40 per gram per hour for plutonium-239. This meant that reactor-bred plutonium was unsuitable for use in a gun-type weapon. The plutonium-240 would start the chain reaction too quickly, causing a predetonation that would release enough energy to disperse
6870-499: A possible source of bombs with a destructiveness vastly greater than anything now known." In February 1940, the U.S. Navy awarded Columbia University $ 6,000, most of which Fermi and Szilard spent on graphite . A team of Columbia professors including Fermi, Szilard, Eugene T. Booth and John Dunning created the first nuclear fission reaction in the Americas, verifying the work of Hahn and Strassmann. The same team subsequently built
7099-422: A procedure for plutonium purification independent of Seaborg's group. When they got hold of a sample in February, this procedure was tested. That month the Metallurgical Laboratory announced that it had determined that there were two different fluorides: the light colored plutonium tetrafluoride (PuF 4 ) and the dark plutonium trifluoride (PuF 3 ). The chemists soon discovered how to make them selectively, and
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7328-470: A ranch. On 16 November 1942, Oppenheimer, Groves, Dudley and others toured the vicinity of the Los Alamos Ranch School . Oppenheimer expressed a strong preference for the site, citing its natural beauty, which, it was hoped, would inspire those working on the project. The engineers were concerned about the poor access road, and whether the water supply would be adequate, but otherwise felt that it
7557-462: A reaction becomes self-sustaining became known as "going critical". Compton reported the success to Conant in Washington, D.C., by a coded phone call, saying, "The Italian navigator [Fermi] has just landed in the new world." In January 1943, Grafton's successor, Major Arthur V. Peterson , ordered Chicago Pile-1 dismantled and reassembled at the Argonne Forest site, as he regarded the operation of
7786-531: A reactor as too hazardous for a densely populated area. The new site, still operated by the Metallurgical Laboratory, became known as ' Site A '. Chicago Pile-3 , the first heavy water reactor, also went critical at this site, on 15 May 1944. After the war, operations at Site A were moved about 6 miles (9.7 km) to DuPage County , the current location of the Argonne National Laboratory . By December 1942 there were concerns that even Oak Ridge
8015-400: A report co-authored with Teller showed that "no self-propagating chain of nuclear reactions is likely to be started". Oppenheimer's deft handling of the July conference impressed his colleagues; his insight and ability to handle even the most difficult people came as a surprise even to those who knew him well. In the wake of the conference, Oppenheimer saw that while they had come to grips with
8244-660: A series of prototype nuclear reactors (or "piles" as Fermi called them) in Pupin Hall at Columbia but were not yet able to achieve a chain reaction. The Advisory Committee on Uranium became the National Defense Research Committee (NDRC) on Uranium when that organization was formed on 27 June 1940. On 28 June 1941, Roosevelt signed Executive Order 8807, which created the Office of Scientific Research and Development (OSRD), under director Vannevar Bush . The office
8473-533: A simpler gun-type design called Little Boy was developed that used uranium-235 . Three methods were employed for uranium enrichment : electromagnetic , gaseous , and thermal . In parallel with the work on uranium was an effort to produce plutonium. After the feasibility of the world's first artificial nuclear reactor, the Chicago Pile-1 , was demonstrated in 1942 at the Metallurgical Laboratory in
8702-455: A small amount of fissile uranium-235 . Until then it had been assumed that such a bomb would require many tons of uranium, and consequently was impractical to build and use. The paper was pivotal in igniting the interest of first the British and later the American authorities in nuclear weapons. He was also responsible for the recruitment of his compatriot Klaus Fuchs to work on Tube Alloys, as
8931-525: A special account not subject to the usual auditing and controls was used to hold Trust monies. Between 1944 and his resignation from the Trust in 1947, Groves deposited a total of $ 37.5 million. Groves appreciated the early British atomic research and the British scientists' contributions to the Manhattan Project but stated that the United States would have succeeded without them, although not in time for
9160-559: A sphere of pure uranium-235, and found that not only could a chain reaction occur, but it might require as little as 1 kilogram (2.2 lb) of uranium-235 to unleash the energy of hundreds of tons of TNT . Their superior, Mark Oliphant , took the Frisch–Peierls memorandum to Sir Henry Tizard , the chairman of the Committee for the Scientific Survey of Air Warfare (CSSAW), who in turn passed it on to George Paget Thomson , to whom
9389-555: A spontaneous fission rate of 40 fissions per gram per hour, which was high but acceptable, the error margin was unacceptably large. In April 1944 they received a sample from the X-10 Graphite Reactor. Tests soon indicated 180 fissions per gram per hour, which was unacceptably high. It fell to Bacher to inform Compton, who was visibly shaken. Suspicion fell on plutonium-240 , an isotope that had not yet been discovered, but whose existence had been suspected, it being simply created by
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9618-533: A student from India. With Kapur he derived the dispersion formula for nuclear reactions originally given in perturbation theory by Gregory Breit and Eugene Wigner , but now included generalising conditions. This is now known as the Kapur–Peierls derivation. It is still used, but in 1947 Wigner and Leonard Eisenbud developed a more widely used alternative method. In 1938, Peierls paid visits to Copenhagen, where he collaborated with Bohr and George Placzek on
9847-484: A superintendent, it enjoyed an excellent teacher:pupil ratio. Numerous technical buildings were constructed. Most were of a semi-permanent type, using gypsum board . They were heated from a central heating plant. Initially this was Boiler House No. 1, which had two coal-fired boilers . This was replaced by Boiler House No. 2, which had six oil-fired boilers. In addition to the main site at Los Alamos, some 25 outlying sites were developed for experimental work. The growth of
10076-528: A wider variety of jobs than the PED; some were cooks, drivers and telephone operators, while others served as librarians, clerks and hospital technicians. Some performed highly specialized scientific research inside the Technical Area. The Special Engineer Detachment (SED) was activated in October 1943 as part of the 9812th Technical Service Unit. It was made up of men with technical skills or advanced education, and
10305-494: A year on sabbatical, Peierls took his place. The position was finally filled permanently by Brian Flowers . Peierls resigned from Harwell in 1957 due to what he saw as a lack of openness in security vetting at the request of the Americans, which he felt indicated a lack of trust in him on the part of senior staff; but he was invited to rejoin in 1960, and did so in 1963, remaining as a consultant for another 30 years. Peierls became
10534-455: Is about four times as large; but until then it had been assumed that such a bomb would require many tons of uranium, and consequently was impractical to build and use. They went on to estimate the size of the explosion, and its physical, military and political effects. The Frisch–Peierls memorandum was pivotal in igniting the interest of first the British and later the American authorities in atomic weapons. In 1941 its findings made their way to
10763-475: Is likely to be started." In Serber's account, Oppenheimer mentioned the possibility of this scenario to Arthur Compton , who "didn't have enough sense to shut up about it. It somehow got into a document that went to Washington" and was "never laid to rest". The Chief of Engineers , Major General Eugene Reybold , selected Colonel James C. Marshall to head the Army's part of the project in June 1942. Marshall created
10992-737: The Belgian Government in Exile was in London. Britain agreed to give the United States most of the Belgian ore, as it could not use most of the supply without restricted American research. In 1944, the Trust purchased 3,440,000 pounds (1,560,000 kg) of uranium oxide ore from companies operating mines in the Belgian Congo. To avoid briefing US Secretary of the Treasury Henry Morgenthau Jr. ,
11221-851: The Berkeley Radiation Laboratory , Compton at the Metallurgical Project in Chicago, and Urey at the SAM Laboratories in New York—Oppenheimer did not have a Nobel Prize , raising concerns that he might not have the prestige to deal with distinguished scientists. There were also security concerns; many of Oppenheimer's closest associates were active members of the Communist Party , including his wife Kitty , girlfriend Jean Tatlock , brother Frank , and Frank's wife Jackie. In
11450-456: The Boltzmann equations for phonons and the umklapp process . He submitted a paper on the subject for his habilitation , acquiring the right to teach at German universities. Physics Today noted that "His many papers on electrons in metals have now passed so deeply into the literature that it is hard to identify his contribution to conductivity in magnetic fields and to the concept of
11679-682: The Bulletin of the Atomic Scientists , was President of the Atomic Scientists' Association in the UK , and was involved in the Pugwash movement , and FREEZE, now known as Saferworld . Genia died on 26 October 1986. Peierls remained active, although his eyesight deteriorated. In 1994, he suffered a combination of health problems, including heart, kidney and lung problems, and relocated himself to Oakenholt,
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#173284501244211908-504: The Bulletin of the Atomic Scientists , was President of the Atomic Scientists' Association in the UK , and was involved in the Pugwash movement . Rudolf Ernst Peierls was born in the Berlin suburb of Oberschöneweide , the youngest of three children of Heinrich Peierls an electrical engineer, from a family of Jewish merchants. His father was the managing director of a cable factory of Allgemeine Elektricitäts-Gesellschaft (AEG), and his mother
12137-561: The Carnegie Institution of Washington and later the Naval Research Laboratory . Murphree also headed an unsuccessful separation project using gas centrifuges . Meanwhile, there were two lines of investigation into nuclear reactor technology : Harold Urey researched heavy water at Columbia, while Arthur Compton organized the Metallurgical Laboratory in early 1942 to study plutonium and reactors using graphite as
12366-526: The Chief of Staff of the Army , General George C. Marshall . Roosevelt chose the Army to run the project rather than the Navy, because the Army had more experience with managing large-scale construction. He agreed to coordinate the effort with the British and on 11 October sent a message to Prime Minister Winston Churchill , suggesting that they correspond on atomic matters. The S-1 Committee meeting on 18 December 1941
12595-562: The Clinton Engineer Works (CEW) in early 1943. While Stone & Webster concentrated on the production facilities, the architectural and engineering firm Skidmore, Owings & Merrill developed a residential community for 13,000. The community was located on the slopes of Black Oak Ridge, from which the new town of Oak Ridge got its name. The Army presence at Oak Ridge increased in August 1943 when Nichols replaced Marshall as head of
12824-968: The Lorentz Medal in 1962, the Max Planck Medal in 1963, the Guthrie Medal and Prize in 1968, the Matteucci Medal in 1982, and the Enrico Fermi Award from the United States Government for exceptional contribution to the science of atomic energy in 1980. In 1986, he was awarded the Copley Medal , and delivered the Rutherford Memorial Lecture , and in 1991 he was awarded the Dirac Medal and Prize . On 2 October 2004,
13053-427: The Los Alamos Laboratory in February 1944; Skyrme followed in July, and Fuchs in August. At Los Alamos, the British Mission was fully integrated into the laboratory, and British scientists worked in most of its divisions, being excluded only from plutonium chemistry and metallurgy. When Oppenheimer appointed Bethe as the head of the laboratory's prestigious Theoretical (T) Division, he offended Edward Teller , who
13282-504: The Manhattan Project on 23 September 1942. He visited Berkeley to look at Lawrence's calutrons , and met with Oppenheimer, who gave him a report on bomb design on 8 October. Groves was interested in Oppenheimer's proposal to establish a separate bomb design laboratory. When they met again in Chicago on October 15, he invited Oppenheimer to discuss the issue. Groves had to catch the 20th Century Limited train back to New York, so he asked Oppenheimer to accompany him so that they could continue
13511-413: The National Bureau of Standards . The division was initially organized into five groups, with original group leaders being McMillan of the E-1 (Proving Ground) Group, Kenneth Bainbridge of the E-2 (Instrumentation) Group, Robert Brode of the E-3 (Fuse Development) Group, Critchfield of the E-4 (Projectile, Target, and Source) Group and Neddermeyer of the E-5 (Implosion) Group. Two more groups were added in
13740-399: The Quebec Agreement on 19 August 1943 merged Tube Alloys with the Manhattan Project. Akers had already cabled London with instructions that Chadwick, Peierls, Oliphant and Simon should leave immediately for North America to join the British Mission to the Manhattan Project , and they arrived the day the agreement was signed. Simon and Peierls were attached to the Kellex Corporation , which
13969-526: The Tennessee Valley Authority could supply ample electric power and the rivers could provide cooling water for the reactors. After examining several sites, the survey team selected one near Elza, Tennessee . Conant advised that it be acquired at once and Styer agreed but Marshall temporized, awaiting the results of Conant's reactor experiments. Of the prospective processes, only Lawrence's electromagnetic separation appeared sufficiently advanced for construction to commence. Marshall and Nichols began assembling
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#173284501244214198-459: The University of Berlin , where he listened to lectures by Max Planck , Walther Bothe and Walther Nernst . Fellow students included Kurt Hirsch and Käte Sperling . The physics laboratory classes were overcrowded, so the first year students were encouraged to take theoretical physics courses instead. Peierls found that he liked the subject. In 1926 Peierls decided to transfer to the University of Munich to study under Arnold Sommerfeld , who
14427-426: The University of Birmingham had made a breakthrough investigating the critical mass of uranium-235 in June 1939. Their calculations indicated that it was within an order of magnitude of 10 kilograms (22 lb), small enough to be carried by contemporary bombers. Their March 1940 Frisch–Peierls memorandum initiated the British atomic bomb project and its MAUD Committee , which unanimously recommended pursuing
14656-625: The University of Chicago , the project designed the X-10 Graphite Reactor and the production reactors at the Hanford Site , in which uranium was irradiated and transmuted into plutonium. The Fat Man plutonium implosion-type weapon was developed in a concerted design and development effort by the Los Alamos Laboratory. The project was also charged with gathering intelligence on the German nuclear weapon project . Through Operation Alsos , Manhattan Project personnel served in Europe, sometimes behind enemy lines, where they gathered nuclear materials and documents, and rounded up German scientists. Despite
14885-438: The University of Hamburg . Granted leave to remain in Britain, he worked at the Victoria University of Manchester with funding from the Academic Assistance Council , which had been set up to help academic refugees from Germany and other fascist countries. Most of his immediate family also left Germany; his brother and his family settling in Britain, and his sister and her family, along with his father and stepmother, moved to
15114-617: The University of Munich under Arnold Sommerfeld , the University of Leipzig under Werner Heisenberg , and ETH Zurich under Wolfgang Pauli . After receiving his DPhil from Leipzig in 1929, he became an assistant to Pauli in Zurich. In 1932, he was awarded a Rockefeller Fellowship , which he used to study in Rome under Enrico Fermi , and then at the Cavendish Laboratory at the University of Cambridge under Ralph H. Fowler . Because of his Jewish background, he elected to not return home after Adolf Hitler's rise to power in 1933, but to remain in Britain, where he worked with Hans Bethe at
15343-569: The University of Wisconsin , Felix Bloch's group from Stanford University and Marshall Holloway 's from Purdue University . He also secured the services of Hans Bethe and Robert Bacher from the Radiation Laboratory at MIT , Edward Teller , Robert F. Christy , Darol K. Froman , Alvin C. Graves and John H. Manley and his group from the Manhattan Project's Metallurgical Laboratory, and Robert R. Wilson and his group, which included Richard Feynman , that had been performing Manhattan Project research at Princeton University . They brought with them
15572-439: The Victoria University of Manchester , then at the Mond Laboratory at Cambridge. In 1937, Mark Oliphant , the newly appointed Australian professor of physics at the University of Birmingham recruited him for a new chair there in applied mathematics. In March 1940, Peierls co-authored the Frisch–Peierls memorandum with Otto Robert Frisch . This short paper was the first to set out that one could construct an atomic bomb from
15801-435: The War Department "for so long as the military necessity continues". The need for land for a new road, and later for a right of way for a 25-mile (40 km) power line, eventually brought wartime land purchases to 45,737 acres (18,509.1 ha), but only $ 414,971 was ultimately spent. The big ticket items were the school, which cost $ 350,000, and the Anchor Ranch, which cost $ 25,000. Both hired lawyers to negotiate deals with
16030-427: The Wykeham Professor of Physics at the University of Oxford in 1963. He remained there until he retired in 1974. He wrote several books including Quantum Theory of Solids (1955), The Laws of Nature (1955), Surprises in Theoretical Physics (1979), More Surprises in Theoretical Physics (1991) and an autobiography, Bird of Passage (1985). Concerned with the nuclear weapons he had helped to unleash, he worked on
16259-534: The discovery of nuclear fission by chemists Otto Hahn and Fritz Strassmann in 1938, and its explanation (and naming) by physicists Lise Meitner and Otto Frisch soon after, opened up the possibility of a controlled nuclear chain reaction using uranium . At the time, few scientists in the United States thought that an atomic bomb was practical, but the possibility that a German atomic bomb project would develop atomic weapons concerned refugee scientists from Nazi Germany and other fascist countries, leading to
16488-407: The mean free path of neutrons in the core and tamper were the same. Bethe's T Division, particularly Serber's T-2 (Diffusion Theory) Group and Feynman's T-4 (Diffusion Problems) Groups, would spend the next few months working on improved models. Bethe and Feynman also developed a formula for the efficiency of the reaction. No formula could be more accurate than the values put into it; the values for
16717-638: The 670 workers in the laboratory, hospital and school were women in October 1944. Most worked in administration, but many women such as Lilli Hornig , Jane Hamilton Hall , and Peggy Titterton worked as scientists and technicians. Charlotte Serber headed the A-5 (Library) Group. A large group of women worked on numerical calculations in the T-5 (Computations) Group. Dorothy McKibbin ran the Santa Fe office, which opened at 109 East Palace Avenue on 27 March 1943. New staff members at
16946-472: The April 1943 conferences as a means of assembling pieces of fissionable material together to form a critical mass. Neddermeyer took a different tack, attempting to crush a hollow cylinder into a solid bar. The idea was to use explosives to crush a subcritical amount of fissile material into a smaller and denser form. When the fissile atoms are packed closer together, the rate of neutron capture increases, and they form
17175-655: The Army allowed the crops to be harvested, but this was not always possible. The land acquisition process dragged on and was not completed before the end of the Manhattan Project in December 1946. The dispute did not delay work. Although progress on the reactor design at Metallurgical Laboratory and DuPont was not sufficiently advanced to accurately predict the scope of the project, a start was made in April 1943 on facilities for an estimated 25,000 workers, half of whom were expected to live on-site. By July 1944, some 1,200 buildings had been erected and nearly 51,000 people were living in
17404-540: The Army's component the Manhattan District; Reybold officially created this district on 13 August. Informally, it was known as the Manhattan Engineer District, or MED. Unlike other districts, it had no geographic boundaries, and Marshall had the authority of a division engineer. Development of Substitute Materials remained as the official codename of the project as a whole but was supplanted over time by "Manhattan". Marshall later conceded that, "I had never heard of atomic fission but I did know that you could not build much of
17633-612: The August 1945 bombing of Hiroshima. The British wartime participation was crucial to the success of the United Kingdom's independent nuclear weapons program after the war when the McMahon Act of 1946 temporarily ended American nuclear cooperation. The day after he took over the project, Groves went to Tennessee with Colonel Marshall to inspect the proposed site there, and Groves was impressed. On 29 September 1942, United States Under Secretary of War Robert P. Patterson authorized
17862-781: The Australian physicist Mark Oliphant , flew to the US in late August 1941 and discovered that data provided by the MAUD Committee had not reached key American physicists. Oliphant set out to find out why the committee's findings were apparently being ignored. He met with the Uranium Committee and visited Berkeley, California , where he spoke persuasively to Ernest O. Lawrence . Lawrence was sufficiently impressed to commence his own research into uranium. He in turn spoke to James B. Conant , Arthur H. Compton and George B. Pegram . Oliphant's mission
18091-722: The British nuclear weapons project was called, which resulted in Peierls falling under suspicion when Fuchs was exposed as a spy for the Soviet Union in 1950. After the war, Peierls returned to the University of Birmingham, where he worked until 1963, and then was the Wykeham Professor of Physics and a Fellow of New College at the University of Oxford until he retired in 1974. At Birmingham he worked on nuclear forces , scattering , quantum field theories , collective motion in nuclei , transport theory and statistical mechanics , and
18320-531: The CSSAW had delegated responsibility for uranium research. CSSAW created the MAUD Committee to investigate. In its final report in July 1941, the MAUD Committee concluded that an atomic bomb was not only feasible, but might be produced as early as 1943. In response, the British government created a nuclear weapons project known as Tube Alloys . There was still little urgency in the United States, which unlike Britain
18549-609: The Corps of Engineers to acquire 56,000 acres (23,000 ha) of land by eminent domain at a cost of $ 3.5 million. An additional 3,000 acres (1,200 ha) was subsequently acquired. About 1,000 families were affected by the order, which came into effect on 7 October. Protests, legal appeals, and a 1943 Congressional inquiry were to no avail. By mid-November U.S. Marshals were posting notices to vacate on farmhouse doors, and construction contractors were moving in. Some families were given two weeks' notice to vacate farms that had been their homes for generations. The ultimate cost of
18778-469: The Los Alamos Laboratory soon discovered that it melted at around 635 °C (1,175 °F). The chemists then turned to techniques for removing light element impurities from the plutonium; but on 14 July 1944, Oppenheimer informed Kennedy that this would no longer be required. The notion of spontaneous fission had been raised by Niels Bohr and John Archibald Wheeler in their 1939 treatment of
19007-502: The M. M. Sundt Company of Tucson, Arizona , with work commenced in December 1942. Groves initially allocated $ 300,000 for construction, three times Oppenheimer's estimate, with a planned completion date of 15 March 1943. It soon became clear that the scope of Project Y was far greater than expected, and by the time Sundt finished on 30 November 1943, over $ 7 million had been spent. The Zia Company took over responsibility for maintenance in April 1946. Oppenheimer initially estimated that
19236-642: The MAUD Committee, but the absurdity of this was soon recognised, and they were made members of its Technical Subcommittee. This did not mean that they were cleared for radar work. When Oliphant made the services of his secretary available for typing up the Peierl's and Frisch's papers for the MAUD Committee in September 1940, they were not allowed to enter the Nuffield Building where she worked, so Peierls submitted them for typing by dictaphone on wax cylinders. Frisch and Peierls thought at first that uranium enrichment
19465-475: The Manhattan District (the military component of the Manhattan Project) surveyed sites around Gallup , Las Vegas , La Ventana, Jemez Springs , and Otowi , and recommended the one near Jemez Springs. On 16 November, Oppenheimer, Groves, Dudley and others toured the site. Oppenheimer feared that the high cliffs surrounding the site would make people feel claustrophobic, while the engineers were concerned with
19694-596: The Manhattan Engineer District. One of his first tasks was to move the district headquarters to Oak Ridge, although the name of the district did not change. In September 1943 the administration of community facilities was outsourced to Turner Construction Company through a subsidiary, the Roane-Anderson Company. Chemical engineers were part of "frantic efforts" to make 10% to 12% enriched uranium 235, with tight security and fast approvals for supplies and materials. The population of Oak Ridge soon expanded well beyond
19923-801: The Manhattan Project conducted weapons testing at Bikini Atoll as part of Operation Crossroads , developed new weapons, promoted the development of the network of national laboratories , supported medical research into radiology and laid the foundations for the nuclear navy . It maintained control over American atomic weapons research and production until the formation of the United States Atomic Energy Commission (AEC) in January 1947. The discovery of nuclear fission by Otto Hahn and Fritz Strassmann in 1938, and its theoretical explanation by Lise Meitner and Otto Frisch , made an atomic bomb theoretically possible. There were fears that
20152-513: The Manhattan Project's emphasis on security, Soviet atomic spies penetrated the program. The first nuclear device ever detonated was an implosion-type bomb during the Trinity test , conducted at White Sands Proving Ground in New Mexico on 16 July 1945. Little Boy and Fat Man bombs were used a month later in the atomic bombings of Hiroshima and Nagasaki , respectively. In the immediate postwar years,
20381-403: The Metallurgical Laboratory, was assigned to assist Oppenheimer by coordinating experimental physics groups scattered across the country. Oppenheimer and Robert Serber of the University of Illinois examined the problems of neutron diffusion—how neutrons moved in a nuclear chain reaction—and hydrodynamics —how the explosion produced by a chain reaction might behave. To review this work and
20610-694: The Netherlands to meet Hans Kramers , and to Copenhagen to meet Niels Bohr . In August 1930 Pauli and Peierls attended a physics congress in Odessa and met a young physics graduate, Eugenia (Genia) Nikolaievna Kannegiesser, who, like Landau, came from Leningrad . Since he did not speak Russian and she did not speak German, they conversed in English. During a subsequent visit by Peierls to lecture in Leningrad they were married on 15 March 1931. However, she had to wait for
20839-550: The Peierls family for a time. Peierls had a Russian wife, as did his brother, and he maintained close contact with colleagues in the Soviet Union before and after the Second World War. While not a communist like Fuchs, Peierls was known to have left-wing political views, and had colleagues with similar views. He was denied a visa to visit the United States to attend a Nuclear Physics Conference in Chicago in 1951. A similar request
21068-411: The President, who approved it by writing "OK FDR" on the document. Compton asked theoretical physicist J. Robert Oppenheimer of the University of California to take over research into fast neutron calculations —key to calculations of critical mass and weapon detonation—from Gregory Breit , who had quit on 18 May 1942 because of concerns over lax operational security. John H. Manley , a physicist at
21297-661: The Quebec Agreement, the Americans' progress and expenditures amazed the British. Chadwick pressed for British involvement in the Manhattan Project to the fullest extent and abandoned hopes of an independent British project during the war. With Churchill's backing, he attempted to ensure that every request from Groves for assistance was honored. The British Mission that arrived in the United States in December 1943 included Niels Bohr , Otto Frisch, Klaus Fuchs , Rudolf Peierls, and Ernest Titterton . More scientists arrived in early 1944. While those assigned to gaseous diffusion left by
21526-529: The Technical Area without proper clearance. In the interest of efficiency, Groves approved an abbreviated process by which Oppenheimer vouched for senior scientists, and three other employees were sufficient to vouch for a junior scientist or technician. The Los Alamos Laboratory was reinforced by a British Mission under James Chadwick. The first to arrive were Otto Frisch and Ernest Titterton ; later arrivals included Niels Bohr and his son Aage Bohr , and Sir Geoffrey Taylor , an expert on hydrodynamics who made
21755-493: The United States through the report of the MAUD Committee , an important trigger in the establishment of the Manhattan Project and the subsequent development of the atomic bomb. With the Frisch-Peierls memorandum and the MAUD Committee report, the British and American scientists were able to begin thinking about how to create a bomb, not whether it was possible. As enemy aliens, Frisch and Peierls were initially excluded from
21984-540: The United States, where he visited Urey and Fermi in New York, Arthur H. Compton in Chicago, Robert Oppenheimer in Berkeley , and Jesse Beams in Charlottesville, Virginia . When George Kistiakowsky argued that a nuclear weapon would do little damage as most of the energy would be expended heating the air, Peierls, Fuchs, Geoffrey Taylor and J. G. Kynch worked out the hydrodynamics to refute this. The signing of
22213-444: The United States, where his uncle Siegfried lived. Peierls collaborated with Bethe on photodisintegration and the statistical mechanics of alloys when challenged by James Chadwick . Their results still serve as the basis for mean-field theories of structural phase changes in complete alloys . Although most of his work continued to be about the electron theory of metals, he also looked at Dirac's hole theory , and co-wrote
22442-566: The Water Boiler, an aqueous homogeneous reactor that was the third reactor in the world to become operational. It also researched the Super, a hydrogen bomb that would use a fission bomb to ignite a nuclear fusion reaction in deuterium and tritium . The Fat Man design was tested in the Trinity nuclear test in July 1945. Project Y personnel formed pit crews and assembly teams for the atomic bombings of Hiroshima and Nagasaki and participated in
22671-475: The academic scientists working on the project. Groves' orders placed him directly under Somervell rather than Reybold, with Colonel Marshall now answerable to Groves. Groves established his headquarters in Washington, D.C., in the New War Department Building , where Colonel Marshall had his liaison office. He assumed command of the Manhattan Project on 23 September 1942. Later that day, he attended
22900-503: The area. The site acquired an irregular shape due to abutting the Bandelier National Monument and a Native American sacred burial ground. An important consideration in the acquisition of the site was the existence of the Los Alamos Ranch School. This consisted of 54 buildings, of which 27 were houses, dormitories or other quarters providing 46,626 square feet (4,331.7 m) of accommodation. The remaining buildings included
23129-514: The autumn of 1943, the E-7 (Delivery) Group under Norman Ramsey and the E-8 (Interior Ballistics) Group under Joseph O. Hirschfelder . A proving ground was established at the Anchor Ranch. The gun would be an unusual one, and it had to be designed in the absence of crucial data about the critical mass. The design criteria were that the gun would have a muzzle velocity of 3,000 feet per second (910 m/s); that
23358-543: The available accommodation and personnel were temporarily lodged in Frijoles Canyon. The houses at Clinton Engineer Works in Oak Ridge, Tennessee and Hanford Engineer Works in Washington state were basic but of a higher standard (as specified by Nichols ) than the houses at Los Alamos (as specified by Groves ), but Nichols said to Los Alamos scientists that housing there was Groves' problem not his. Rents were set based on
23587-670: The bomb design team at Los Alamos needed them, despite the risk of revealing weapon design secrets. In August 1943 Churchill and Roosevelt negotiated the Quebec Agreement , which established the Combined Policy Committee to coordinate the efforts of the US and UK; Canada was not a signatory, but the Agreement provided for a Canadian representative on the Combined Policy Committee in view of Canada's contribution to
23816-492: The bombing as weaponeers and observers. After the war ended, the laboratory supported the Operation Crossroads nuclear tests at Bikini Atoll . A new Z Division was created to control testing, stockpiling and bomb assembly activities, which were concentrated at Sandia Base . The Los Alamos Laboratory became Los Alamos Scientific Laboratory in 1947. The discovery of the neutron by James Chadwick in 1932, followed by
24045-632: The branch office in Santa Fe, where she met new arrivals and issue them with passes. An Army-OSRD council on 25 June 1942 decided to build a pilot plant for plutonium production in the Argonne Forest preserve , southwest of Chicago. In July, Nichols arranged for a lease of 1,025 acres (415 ha) from the Cook County Forest Preserve District , and Captain James F. Grafton was appointed Chicago area engineer. It soon became apparent that
24274-421: The chairman of the National Defense Research Committee (NDRC). On 19 October, Groves approved the establishment of a bomb laboratory. While Oppenheimer seemed the logical person to direct the new laboratory, which became known as Project Y, he had little administrative experience; Bush, Conant, Lawrence and Harold Urey all expressed reservations about this. Moreover, unlike his other project leaders—Lawrence at
24503-544: The church. Peierls commenced school a year late because he needed glasses, and his parents did not trust him not to lose them or break them. After two years at the local preparatory school, he entered his local gymnasium , the Humboldt Gymnasium [ de ] , where he spent the next nine years, passing his abitur examinations in 1925. He wanted to study engineering, but his parents, who doubted his practical abilities, suggested physics instead. He entered
24732-459: The classical theory of metals, and Heisenberg sensed an opportunity to demonstrate that quantum mechanics could explain it. Peierls was able to do so, resulting in his first published paper. Heisenberg left in 1929 to lecture in America, China, Japan and India, and on his recommendation Peierls moved on to ETH Zurich , where he studied under Wolfgang Pauli . Pauli set him a problem of investigating
24961-402: The construction camp. As area engineer, Matthias exercised overall control of the site. At its peak, the construction camp was the third most populous town in Washington state. Hanford operated a fleet of over 900 buses, more than the city of Chicago. Like Los Alamos and Oak Ridge, Richland was a gated community with restricted access, but it looked more like a typical wartime American boomtown:
25190-611: The conventional gun. Nor did it require rifling or recoil mechanisms. Pressure curves were computed under Hirschfelder's supervision at the Geophysical Laboratory prior to his joining the Los Alamos Laboratory. While they waited for the guns to be fabricated by the Naval Gun Factory , various propellants were tested. Hirschfelder sent John L. Magee to the Bureau of Mines ' Experimental Mine at Bruceton, Pennsylvania to test
25419-426: The critical mass before enough plutonium reacted. A faster gun was suggested but found to be impractical. So too was the possibility of separating the isotopes, as plutonium-240 is even harder to separate from plutonium-239 than uranium-235 from uranium-238. Work on an alternative method of bomb design, known as implosion, had begun by Neddermeyer's E-5 (Implosion) group. Serber and Tolman had conceived implosion during
25648-427: The cross sections were dubious, and had not yet been determined for plutonium. Measurement of these values would be a priority, but the laboratory possessed just 1 gram of uranium-235, and only a few micrograms of plutonium. This task fell to Bacher's P Division. Williams P-2 (Electrostatic Generator) Group carried out the first experiment in July 1943, when it used the larger of the two Van de Graaff generators to measure
25877-503: The damage could be increased if the bomb was detonated at an altitude comparable to the damage radius, approximately 1 to 2 kilometers (3,300 to 6,600 ft). Parsons was appointed the head of Ordnance and Engineering Division in June 1943 on the recommendation of Bush and Conant. To staff the division, Tolman, who acted as a coordinator of the gun development effort, brought in John Streib, Charles Critchfield and Seth Neddermeyer from
26106-471: The deuterium concentration in the water from 2.3% to 99.8%. For this process, Hugh Taylor of Princeton developed a platinum-on-carbon catalyst for the first three stages while Urey developed a nickel- chromia one for the fourth stage tower. The final cost was $ 2.8 million. The Canadian Government did not officially learn of the project until August 1942. Trail's heavy water production started in January 1944 and continued until 1956. Heavy water from Trail
26335-489: The development of an atomic bomb. In July 1940, Britain had offered to give the United States access to its research, and the Tizard Mission 's John Cockcroft briefed American scientists on British developments. He discovered that the American project was smaller than the British, and not as advanced. As part of the scientific exchange, the MAUD Committee's findings were conveyed to the United States. One of its members,
26564-408: The discussion. Groves, Oppenheimer, Colonel James C. Marshall , and Lieutenant Colonel Kenneth Nichols all squeezed into Nichol's single roomette compartment to discuss how a bomb laboratory could be created and how it would function. Groves subsequently had Oppenheimer come to Washington, D.C. , where the matter was discussed with Vannevar Bush , the director of the OSRD, and James B. Conant ,
26793-459: The drafting of the Einstein–Szilard letter to warn President Franklin D. Roosevelt . This prompted preliminary research in the United States, beginning in late 1939. Progress was slow in the United States, but in Britain, Otto Frisch and Rudolf Peierls , two refugee physicists from Germany at the University of Birmingham , examined the theoretical issues involved in developing, producing and using atomic bombs. They considered what would happen to
27022-482: The efficiency of the bomb as it exploded. As the idea of the fission bomb was theoretically settled—at least until more experimental data was available—Edward Teller pushed for discussion of a more powerful bomb: the "super", now usually referred to as a " hydrogen bomb ", which would use the force of a detonating fission bomb to ignite a nuclear fusion reaction in deuterium and tritium . Teller proposed scheme after scheme, but Bethe refused each one. The fusion idea
27251-420: The efficiency of the bomb as it exploded. Considering the idea of the fission bomb theoretically settled—at least until more experimental data was available—the Berkeley conference then turned in a different direction. Edward Teller pushed for discussion of a more powerful bomb: the "Super", usually referred to today as a " hydrogen bomb ", which would use the explosive force of a detonating fission bomb to ignite
27480-544: The effort. An agreement between Roosevelt and Churchill known as the Hyde Park Aide-Mémoire , signed in late September 1944, extended the Quebec Agreement to the postwar period and suggested that "when a 'bomb' is finally available, it might perhaps, after mature consideration, be used against the Japanese, who should be warned that this bombardment will be repeated until they surrender". When cooperation resumed after
27709-458: The elements tested except for plutonium, which they were unable to measure accurately enough because the only sample they had was five 20 μg samples created by the 60-inch cyclotron at Berkeley. They did observe that measurements taken at Los Alamos were greater than those made at Berkeley, which they attributed to cosmic rays , which are more numerous at Los Alamos, which is 7,300 feet (2,200 m) above sea level. While their measurements indicated
27938-517: The end, Groves personally issued instructions to clear Oppenheimer on 20 July 1943. The idea of locating Project Y at the Metallurgical Laboratory in Chicago, or the Clinton Engineer Works in Oak Ridge, Tennessee , was considered, but in the end it was decided that a remote location would be best. A site in the vicinity of Los Angeles was rejected on security grounds, and one near Reno, Nevada as being too inaccessible. On Oppenheimer's recommendation,
28167-529: The exacting purity requirement could be met. Only microscopic quantities of plutonium were available until the X-10 Graphite Reactor at the Clinton Engineer Works came online on 4 November 1943, but there were already some worrying signs. When plutonium fluoride was produced at the Metallurgical Laboratory, it was sometimes light colored, and sometimes dark, although the chemical process was
28396-418: The fall of 1944, the thirty-five working under Oliphant with Lawrence at Berkeley were assigned to existing laboratory groups and most stayed until the end of the war. The nineteen sent to Los Alamos also joined existing groups, primarily related to implosion and bomb assembly, but not the plutonium-related ones. The Quebec Agreement specified that nuclear weapons would not be used against another country without
28625-623: The first nuclear weapons . It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the project was directed by Major General Leslie Groves of the U.S. Army Corps of Engineers . Nuclear physicist J. Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the bombs. The Army program was designated the Manhattan District , as its first headquarters were in Manhattan ;
28854-536: The first Canadian reactor, and the first to be completed outside the United States, when it went critical in September 1945; ZEEP remained in use by researchers until 1970. A larger 10 MW NRX reactor, which was designed during the war, was completed and went critical in July 1947. The Eldorado Mine at Port Radium was a source of uranium ore. Rudolf Peierls Sir Rudolf Ernst Peierls , CBE FRS ( / ˈ p aɪ . ər l z / ; German: [ˈpaɪɐls] ; 5 June 1907 – 19 September 1995)
29083-439: The fissile material into a critical mass. The simplest was shooting a "cylindrical plug" into a sphere of "active material" with a " tamper "—dense material that would focus neutrons inward and keep the reacting mass together to increase its efficiency. They also explored designs involving spheroids , a primitive form of "implosion" suggested by Richard C. Tolman , and the possibility of autocatalytic methods , which would increase
29312-422: The fissile material into a critical mass. The simplest was shooting a "cylindrical plug" into a sphere of "active material" with a "tamper"—dense material to focus neutrons inward and keep the reacting mass together to increase its efficiency. They also explored designs involving spheroids , a primitive form of " implosion " suggested by Richard C. Tolman , and the possibility of autocatalytic methods to increase
29541-807: The following year was granted, but in 1957 the Americans expressed concerns about him, indicating that they were unwilling to share information with the Atomic Energy Research Establishment at Harwell while he remained as a consultant. Physicists were in demand after the war, and Peierls received offers from several universities. He seriously considered an offer of a position at Cambridge from William Lawrence Bragg , but decided to return to Birmingham. He worked on nuclear forces , scattering , quantum field theories , collective motion in nuclei , transport theory , and statistical mechanics . Peierls had largely left solid state physics behind when, in 1953, he began collecting his lecture notes on
29770-549: The former turned out to be easier to reduce to metal. Measurements in March 1944 indicated a density of between 19 and 20 g/cm. Eric Jette's CM-8 (Plutonium Metallurgy) Group began experimenting with plutonium metal after gram quantities were received at the Los Alamos Laboratory in March 1944. By heating it, the metallurgists discovered five temperatures between 137 and 580 °C (279 and 1,076 °F) at which it suddenly started absorbing heat without increasing in temperature. This
29999-524: The fusing systems, testing radar altimeters , proximity fuses and barometric altimeter fuses. Tests were conducted with a frequency modulated type radar altimeter known as AYD and a pulse type known as 718. The AYD modifications were made by the Norden Laboratories Corporation under an OSRD contract. When the manufacturer of 718, RCA , was contacted, it was learned that a new tail warning radar , AN/APS-13 , later nicknamed Archie ,
30228-571: The general theory of fission reactions, Oppenheimer and Fermi convened meetings at the University of Chicago in June and at the University of California in Berkeley, in July with theoretical physicists Hans Bethe , John Van Vleck , Edward Teller , Emil Konopinski , Robert Serber, Stan Frankel , and Eldred C. Nelson, the latter three former students of Oppenheimer, and experimental physicists Emilio Segrè , Felix Bloch , Franco Rasetti , John Manley, and Edwin McMillan . They tentatively confirmed that
30457-464: The general theory of fission reactions, Oppenheimer and Fermi convened meetings at the University of Chicago in June and at the University of California in July 1942 with theoretical physicists Hans Bethe , John Van Vleck , Edward Teller, Emil Konopinski , Robert Serber, Stan Frankel , and Eldred C. (Carlyle) Nelson, and experimental physicists Emilio Segrè , Felix Bloch , Franco Rasetti , Manley, and Edwin McMillan . They tentatively confirmed that
30686-481: The government, but Hispanic homesteaders were paid as little as $ 7 an acre (equivalent to $ 123 in 2023). Grazing permits were withdrawn, and private land was purchased or condemned under eminent domain using the authority of the Second War Powers Act . Petitions of condemnation were worded to cover all mineral, water, timber and other rights, so private individuals would have no reason whatsoever to enter
30915-399: The gun-type design known as Little Boy was developed using uranium-235 . Chemists at the Los Alamos Laboratory developed methods of purifying uranium and plutonium, the latter a metal that only existed in microscopic quantities when Project Y began. Its metallurgists found that plutonium had unexpected properties, but were nonetheless able to cast it into metal spheres. The laboratory built
31144-415: The gun-type proved impractical for some reason. Theoretical physicists like Bethe, Oppenheimer and Teller were intrigued by the idea of a design of an atomic bomb that made more efficient use of fissile material, and permitted the use of material of lower purity. These were advantages of particular attraction to Groves. But while Neddermeyer's 1943 and early 1944 investigations into implosion showed promise, it
31373-401: The head of the Corps of Engineers Construction Division, Major General Thomas M. Robbins , and his deputy, Colonel Leslie Groves . Reybold, Somervell, and Styer decided to call the project "Development of Substitute Materials", but Groves felt that this would draw attention. Since engineer districts normally carried the name of the city where they were located, Marshall and Groves agreed to name
31602-411: The highest rating he could assign was AA-3, although he was willing to provide a AAA rating on request for critical materials if the need arose. Nichols and Marshall were disappointed; AA-3 was the same priority as Nichols' TNT plant in Pennsylvania. Vannevar Bush became dissatisfied with Colonel Marshall's failure to get the project moving forward expeditiously and felt that more aggressive leadership
31831-528: The importance of top priority. Most everything proposed in the Roosevelt administration would have top priority. That would last for about a week or two and then something else would get top priority". One of Groves' early problems was to find a director for Project Y , the group that would design and build the bomb. The obvious choice was one of the three laboratory heads, Urey, Lawrence, or Compton, but they could not be spared. Compton recommended Oppenheimer, who
32060-608: The income of the occupant. Transient visitors to Los Alamos were accommodated in the Fuller Lodge , the Guest Cottage or the Big House, which had once been part of the Los Alamos Ranch School. A school was established in 1943, catering for both grade school and high school, and 140 children were enrolled; 350 by 1946. Education was free, as was a nursery school for working mothers. With 18 grade-school teachers, 13 high-school teachers, and
32289-492: The industrial manufacturing area of Ontario and Quebec, and proximity to a rail head adjacent to a large military base, Camp Petawawa . Located on the Ottawa River, it had access to abundant water. The first director of the new laboratory was Hans von Halban . He was replaced by John Cockcroft in May 1944, who was succeeded by Bennett Lewis in September 1946. A pilot reactor known as ZEEP (zero-energy experimental pile) became
32518-425: The initial plans, and peaked at 75,000 in May 1945, by which time 82,000 people were employed at the Clinton Engineer Works, and 10,000 by Roane-Anderson. The idea of locating Project Y at Oak Ridge was considered, but it was decided that it should be in a remote location. On Oppenheimer's recommendation, the search for a suitable site was narrowed to the vicinity of Albuquerque, New Mexico , where Oppenheimer owned
32747-491: The issues involved in setting up a laboratory in a remote area and should be appointed as its director. Groves personally waived the security requirements and issued Oppenheimer's clearance on 20 July 1943. The British and Americans exchanged nuclear information but did not initially combine their efforts; during 1940-41 the British project ( Tube Alloys ) was larger and more advanced. Britain rebuffed attempts by Bush and Conant in August 1941 to strengthen cooperation because it
32976-518: The laboratory was located on the isolated Pajarito Plateau in Northern New Mexico . The wartime laboratory occupied buildings that had once been part of the Los Alamos Ranch School . The development effort initially focused on a gun-type fission weapon using plutonium called Thin Man . In April 1944, the Los Alamos Laboratory determined that the rate of spontaneous fission in plutonium bred in
33205-499: The laboratory's plan for the rest of the year. Oppenheimer estimated the critical mass of a uranium-235 gadget with a formula based on diffusion theory derived at Berkeley by Stan Frankel and E. C. Nelson. This gave a value for a uranium-235 gadget with a perfect tamper of 25 kg; but this was only an approximation. It was based on simplifying assumptions, notably that all neutrons had the same speed, that all collisions were elastic , that they were scattered isotropically , and that
33434-519: The land acquisition, which was not completed until March 1945, was only about $ 2.6 million—around $ 47 an acre. When presented with a proclamation declaring Oak Ridge a total exclusion area that no one could enter without military permission, the Governor of Tennessee , Prentice Cooper , angrily tore it up. Initially known as the Kingston Demolition Range, the site was officially renamed
33663-418: The latter worked at the Clinton Engineer Works , whereas Peierls did not. There were good reasons for the postwar intelligence agencies to suspect Peierls. He not only had recruited Fuchs, and served as his "sponsor" on recruitment and security matters, but had pressed the authorities for Fuchs to be given a full security clearance without which he could not have assisted Peierls in his work. Fuchs lived with
33892-461: The making of fast neutron calculations —the key to calculations of critical mass and weapon detonation—to Gregory Breit , who was given the title of "Co-ordinator of Rapid Rupture", and Oppenheimer as an assistant. But Breit disagreed with other scientists working at the Metallurgical Laboratory , particularly Enrico Fermi , over the security arrangements, and resigned on 18 May 1942. Compton then appointed Oppenheimer to replace him. John H. Manley ,
34121-653: The mechanism of nuclear fission. The first attempt to discover spontaneous fission in uranium was made by Willard Libby , but he failed to detect it. It had been observed in Britain by Frisch and Titterton, and independently in the Soviet Union by Georgy Flyorov and Konstantin Petrzhak in 1940; the latter are generally credited with the discovery. Compton had also heard from the French physicist Pierre Auger that Frédéric Joliot-Curie had detected what might have been spontaneous fission in polonium . If true, it might preclude
34350-484: The military necessity continues". Wartime land purchases eventually came to 49,383 acres (19,985 ha), but only $ 414,971 was spent. Work commenced in December 1942. Groves initially allocated $ 300,000 for construction, three times Oppenheimer's estimate, but by the time Sundt finished on 30 November 1943, over $ 7 million had been spent. During the war, Los Alamos was referred to as "Site Y" or "the Hill". Initially it
34579-551: The military profile was lower, and physical security elements like high fences and guard dogs were less evident. Canada provided research, extraction and production of uranium and plutonium, and Canadian scientists worked at Los Alamos. Cominco had produced electrolytic hydrogen at Trail, British Columbia , since 1930. Urey suggested in 1941 that it could produce heavy water. To the existing $ 10 million plant consisting of 3,215 cells consuming 75 MW of hydroelectric power, secondary electrolysis cells were added to increase
34808-542: The month before, and the latter had calculated that neutron emitters like boron had to be restricted to one part in a hundred billion. There was some doubt about whether a chemical process could be developed that could ensure this level of purity, and Chadwick brought the matter to the S-1 Executive Committee's attention for it to be considered further. Four days later, though, Lawrence, Oppenheimer, Compton and McMillan reported to Conant that they had confidence that
35037-505: The mutual consent of the US and UK. In June 1945, Wilson agreed that the nuclear bombing of Japan would be recorded as a decision of the Combined Policy Committee. The Combined Policy Committee created the Combined Development Trust in June 1944, with Groves as its chairman, to procure uranium and thorium ores on international markets. The Belgian Congo and Canada held much of the world's uranium outside Eastern Europe, and
35266-458: The name gradually superseded the official codename, Development of Substitute Materials , for the entire project. The project absorbed its earlier British counterpart, Tube Alloys , and subsumed the program from the American civilian Office of Scientific Research and Development . The Manhattan Project employed nearly 130,000 people at its peak and cost nearly US$ 2 billion (equivalent to about $ 27 billion in 2023), over 80 percent of which
35495-403: The necessary resources. The first step was to obtain a high priority rating for the project. The top ratings were AA-1 through AA-4 in descending order, although there was a special AAA rating reserved for emergencies. Ratings AA-1 and AA-2 were for essential weapons and equipment, so Colonel Lucius D. Clay , the deputy chief of staff at Services and Supply for requirements and resources, felt that
35724-487: The next most desirable accommodation was the apartments built by Sundt. A typical two-storey building held four families. Each Sundt apartment had two or three bedrooms, a kitchen with a cranky black coal stove, and a small bathroom. J. E. Morgan and Sons supplied 56 prefabricated dwellings that became known as "Morganville". The Robert E. McKee Company built a part of the town known as "McKeeville". In June through October 1943, and again in June and July 1944, numbers outstripped
35953-696: The nuclear weapons project, he was appointed a Commander of the Order of the British Empire in the 1946 New Year Honours , and was awarded the US Medal of Freedom with Silver Palm in 1946. Peierls was responsible for the recruitment of Fuchs to the British project, an action which was to result in Peierls falling under suspicion when Fuchs was exposed as a Soviet spy in 1950. In 1999, The Spectator garnered outrage from Peierls's family when it published an article by journalist Nicholas Farrell that alleged that Peierls
36182-541: The number of dependents increased. This trend accelerated with the end of the war and the replacement of military personnel with civilians with families. Due to the highly classified nature of the work, no census of the population of Los Alamos was conducted until April 1946. Birth certificates of babies born in Los Alamos during the war listed their place of birth as PO Box 1663 in Santa Fe. All letters and packages came through that address. The most desirable accommodation were
36411-653: The passage of the Atomic Energy Act of 1946 , known as the McMahon Act, all British government employees had to leave. All had left by the end of 1946, except for Titterton, who was granted a special dispensation, and remained until 12 April 1947. The British Mission ended when he departed. In 1943, development efforts were directed to a gun-type fission weapon using plutonium called Thin Man . The names for all three atomic bomb designs— Fat Man , Thin Man, and Little Boy —were chosen by Serber based on their shapes. Thin Man
36640-407: The peak pressure, which depends on the cube root of its energy. Bethe then calculated that a 10 kilotonnes of TNT (42 TJ) explosion would result in an overpressure of 0.1 standard atmospheres (10 kPa) at 3.5 kilometers (2.2 mi), and therefore result in severe damage within that radius. Von Neumann also suggested that, because pressure increases when shock waves bounce off solid objects,
36869-595: The physics of the MAUD Committee report, which was discussed at a meeting at the General Electric Research Laboratory in Schenectady, New York , on 21 October 1941. In December 1941, the S-1 Section of the Office of Scientific Research and Development (OSRD) placed Arthur H. Compton in charge of overseeing the scientific research for production and design of the bomb. He delegated bomb design and
37098-483: The physics, considerable work was still required on the engineering, chemistry, metallurgy and ordnance aspects of building an atomic bomb. He became convinced that bomb design would require an environment where people could freely discuss problems and thereby reduce wasteful duplication of effort. He reasoned that this could best be reconciled with security by creating a central laboratory in an isolated location. Brigadier General Leslie R. Groves Jr. became director of
37327-501: The plutonium itself; their main concern was the issue Chadwick had raised about interaction with light element impurities. Segrè and his group of young physicists set up their experiment in an old Forest Service log cabin in Pajarito Canyon, about 14 miles (23 km) from the Technical Area, in order to minimize background radiation emanating for other research at the Los Alamos Laboratory. By August 1943, they had good values for all
37556-501: The possibility of flooding. The party then moved on to the Otowi site, the vicinity of the Los Alamos Ranch School . Oppenheimer was impressed by and expressed a strong preference for the site, citing its natural beauty and views of the Sangre de Cristo Mountains , which, he hoped, would inspire those who would work on the project. The engineers were concerned about the poor access road, and whether
37785-454: The professor of physics at the University of Birmingham , and he approached Peierls about a new chair in applied mathematics that he was creating there. (Applied mathematics being what would today be called theoretical physics.) Peierls got the job despite competition from Harrie Massey and Harry Jones [ de ] . The appointment at last gave Peierls a secure, permanent position. His students included Fred Hoyle and P. L. Kapur ,
38014-669: The propellant and ignition system. Test firing was conducted at the Anchor Ranch with a 3-inch (76 mm)/50 caliber gun . This allowed the fine-tuning of the testing instrumentation. The first two tubes arrived at Los Alamos on 10 March 1944, and test firing began at the Anchor Ranch under the direction of Thomas H. Olmstead, who had experience in such work at the Naval Proving Ground in Dahlgren, Virginia . The primers were tested and found to work at pressures up to 80,000 pounds per square inch (550,000 kPa). Brode's group investigated
38243-451: The ratio of the neutron per fission in plutonium against that of uranium-235. This involved some negotiation with the Metallurgical Laboratory to obtain 165 μg of plutonium, which was received at Los Alamos on 10 July 1943. Bacher was able to report that the number of neutrons per fission of plutonium-239 was 2.64 ± 0.2, about 1.2 times as much as uranium-235. Titterton and Boyce McDaniel of Wilson's P-1 (Cyclotron) Group attempted to measure
38472-493: The research of Enrico Fermi and others into nuclear chain reactions . They had it signed by Albert Einstein and delivered to President Franklin D. Roosevelt . Roosevelt called on Lyman Briggs of the National Bureau of Standards to head an Advisory Committee on Uranium ; Briggs met with Szilard, Wigner and Edward Teller in October 1939. The committee reported back to Roosevelt in November that uranium "would provide
38701-416: The residents of Los Alamos became fully-fledged citizens of New Mexico on 10 June 1949. Initially Los Alamos was to have been a military laboratory with Oppenheimer and other researchers commissioned into the Army. Oppenheimer went so far as to order himself a lieutenant colonel's uniform, but two key physicists, Robert Bacher and Isidor Rabi , balked at the idea. Conant, Groves and Oppenheimer then devised
38930-487: The same. When they managed to reduce it to plutonium metal in November 1943, the density was measured at 15 g/cm, and a measurement using X-ray scattering techniques pointed to a density of 13 g/cm. This was bad; it had been assumed that its density was the same as uranium, about 19 g/cm. If these figures were correct, far more plutonium would be needed for a bomb. Kennedy disliked Seaborg's ambitious and attention-seeking manner, and with Arthur Wahl had devised
39159-517: The scale of operations was too great for the area, and it was decided to build the pilot plant at Oak Ridge and keep a research and testing facility in Chicago. Delays in establishing the plant at Argonne led Arthur Compton to authorize the Metallurgical Laboratory to construct the first nuclear reactor beneath the bleachers of Stagg Field at the University of Chicago. The reactor required an enormous amount of highly purified graphite blocks and uranium in both metallic and powdered oxide forms. At
39388-402: The search was narrowed to the vicinity of Albuquerque, New Mexico , where Oppenheimer owned a ranch in the Sangre de Cristo Range . The climate was mild, there were air and rail connections to Albuquerque, it was sufficiently distant from the West Coast of the United States for a Japanese attack not to be an issue, and the population density was low. In October 1942, Major John H. Dudley of
39617-544: The secret Los Alamos site were not given in advance any directions to the site or security credentials. They were told to report to the Santa Fe office, where McKibbin provided them with such things and thereby became the gatekeeper of Los Alamos. The Los Alamos Laboratory had a governing board, the members of which were Oppenheimer, Bacher, Bethe, Kennedy, D. L. Hughes (Personnel Director), D. P. Mitchell (Procurement Director) and Deak Parsons. McMillan, George Kistiakowsky and Kenneth Bainbridge were later added. The laboratory
39846-421: The site be located far from the existing uranium production facility at Oak Ridge. In December 1942, Groves dispatched Colonel Franklin Matthias and DuPont engineers to scout potential sites. Matthias reported that Hanford Site near Richland, Washington , was "ideal in virtually all respects". It was isolated and near the Columbia River , which could supply sufficient water to cool the reactors. Groves visited
40075-484: The site in January and established the Hanford Engineer Works (HEW), codenamed "Site W". Under Secretary Patterson gave his approval on 9 February, allocating $ 5 million for the acquisition of 430,000 acres (170,000 ha). The federal government relocated some 1,500 residents of nearby settlements, as well as the Wanapum and other tribes using the area. A dispute arose with farmers over compensation for crops, which had already been planted. Where schedules allowed,
40304-493: The six existing log and stone cottages that had once housed the headmaster and the Los Alamos Ranch School faculty. They were the only dwellings at Los Alamos that had bathtubs, and became known as "Bathtub Row". Oppenheimer lived on Bathtub Row; his next-door neighbor was Captain W. S. "Deak" Parsons , the head of the Ordnance and Engineering Division. Parsons' house was slightly larger, because Parsons had two children and Oppenheimer, at that point, had only one. After Bathtub Row,
40533-521: The subject into a book. Reconsidering the way that the atoms in metal crystals are arranged, he noted an instability. This became known as the Peierls transition . Peierls built up the physics department at Birmingham by attracting high quality researchers. These included Gerald E. Brown , Max Krook , Tony Skyrme , Dick Dalitz , Freeman Dyson , Luigi Arialdo Radicati di Brozolo , Stuart Butler , Walter Marshal , Stanley Mandelstam and Elliott H. Lieb . An undergraduate school of mathematical physics
40762-487: The supply completely. Residents had to draw water from 15 tanker trucks that carried 300,000 US gallons (1,100,000 L) per day. Because its name was secret, Los Alamos was referred to as "Site Y"; to residents it was known as "The Hill". Because they lived on Federal land, the state of New Mexico did not allow residents of Los Alamos to vote in elections, although it did require them to pay state income taxes. A drawn-out series of legal and legislative battles lay ahead before
40991-497: The techniques were developed to confirm them experimentally. Peierls accepted an offer from Pauli to become his assistant in place of Felix Bloch . Lev Landau was there at this time on a scholarship from the government of the Soviet Union , and Peierls and Landau became friends. They collaborated on deriving a series of wave equations similar to the Schrödinger equation for photons . Unfortunately, their equations, while complicated, were nonsensical. In 1930, Peierls travelled to
41220-401: The time it took for prompt neutrons to be emitted from a uranium-235 nucleus when it fissions. They calculated that most were emitted in less than 1 nanosecond . Subsequent experiments demonstrated that fission took less than a nanosecond too. Confirmation of the theorists' contention that the number of neutrons emitted per fission was the same for both fast and slow neutrons took longer, and
41449-528: The time, there was a limited source of pure uranium metal; Frank Spedding of Iowa State University was able to produce only two short tons . Three short tons was supplied by Westinghouse Lamp Plant , produced in a rush with makeshift process. A large square balloon was constructed by Goodyear Tire to encase the reactor. On 2 December 1942, a team led by Enrico Fermi initiated the first artificial self-sustaining nuclear chain reaction in an experimental reactor known as Chicago Pile-1 . The point at which
41678-436: The town outpaced the sewage system, and by late 1945 there were electrical outages. Lights had to be shut off during the day, and between 7 and 10 pm. Water also ran short. During the autumn of 1945, consumption was 585,000 US gallons (2,210,000 L) per day, but the water supply could furnish only 475,000 US gallons (1,800,000 L). On 19 December, pipes that had been laid above ground to save time in 1943 froze, cutting off
41907-515: The township for emergencies. Since there was no way to prevent the lines being tapped, classified information could not be discussed over the phone lines. Initially the phone lines were operable only during business hours until enough WACs arrived to staff the switchboard around the clock. Women at Los Alamos were encouraged to work, due to the shortage of labor and security concerns over bringing in local workers. About 60 wives of scientists were at work in Technical Area by September 1943. About 200 of
42136-431: The tube would weigh only 1 short ton (0.91 t) instead of the conventional 5 short tons (4.5 t) for a tube with that energy; that, as a consequence it would be made of alloyed steel; that it should have a maximum breech pressure of 75,000 pounds per square inch (520,000 kPa ); and that it should have three independent primers . Because it would need to be fired only once, the barrel could be made lighter than
42365-428: The tutelage of Heisenberg and Pauli. His early work on quantum physics led to the theory of positive carriers to explain the thermal and electrical conductivity behaviours of semiconductors . He was a pioneer of the concept of "holes" in semiconductors. He established "zones" before Léon Brillouin , despite Brillouin's name being currently attached to the idea, and applied it to phonons . Doing this, he discovered
42594-438: The two countries were reversed, and in January 1943 Conant notified the British that they would no longer receive atomic information except in certain areas. The British investigated the possibility of an independent nuclear program but determined that it could not be ready in time to impact the war in Europe . By March 1943 Conant decided that James Chadwick and one or two other British scientists were important enough that
42823-470: The use of polonium in the neutron initiators; if true for plutonium, it might mean that the gun-type design would not work. The consensus at the Los Alamos Laboratory was that it was not true, and that Joliot-Curie's results had been distorted by impurities. At the Los Alamos Laboratory, Emilio Segrè's P-5 (Radioactivity) Group set out to measure it in uranium-234 , −235 and −238, plutonium, polonium, protactinium and thorium . They were not too worried about
43052-462: The vibration of atoms in a crystal lattice. Peierls explored—and named—the phenomenon of umklapp scattering . He submitted this work as his DPhil thesis, Zur kinetischen Theorie der Wärmeleitung in Kristallen (On the Kinetic Theory of Heat Conduction in Crystals), which was accepted by the University of Leipzig in 1929. His theory made specific predictions of the behaviour of metals at very low temperatures, but another twenty years would pass before
43281-514: The water supply would be adequate, but otherwise felt that it was ideal. The United States Under Secretary of War , Robert P. Patterson , approved the acquisition of the site on 25 November 1942, authorizing $ 440,000 for the purchase of the site of 54,000 acres (22,000 ha), all but 8,900 acres (3,600 ha) of which were already owned by the Federal Government. Secretary of Agriculture Claude R. Wickard granted use of some 45,100 acres (18,300 ha) of United States Forest Service land to
43510-429: The work could be performed by 50 scientists and 50 technicians. Groves tripled this number to 300. The actual population, including family members, was about 3,500 by the end of 1943, 5,700 by the end of 1944, 8,200 by the end of 1945, and 10,000 by the close of 1946. Initially, all of the population were workers, as they were the only ones for whom housing was supplied, but as time went on and more housing became available,
43739-445: The work on radar at the University of Birmingham because it was considered too secret for scientists who were enemy aliens . Peierls was naturalised as a British subject on 27 March 1940. He was eager to participate in the fight against fascism and militarism, but the only organisation that would accept him was the Auxiliary Fire Service . He accepted an offer from the University of Toronto to send his two children to live with
43968-514: Was "pervaded by an atmosphere of enthusiasm and urgency" in the wake of the attack on Pearl Harbor and the United States declaration of war on Japan and on Germany . Work was proceeding on three techniques for isotope separation : Lawrence and his team at the University of California investigated electromagnetic separation , Eger Murphree and Jesse Wakefield Beams 's team looked into gaseous diffusion at Columbia University , and Philip Abelson directed research into thermal diffusion at
44197-412: Was a German-born British physicist who played a major role in Tube Alloys , Britain's nuclear weapon programme, as well as the subsequent Manhattan Project , the combined Allied nuclear bomb programme. His 1996 obituary in Physics Today described him as "a major player in the drama of the eruption of nuclear physics into world affairs". Peierls studied physics at the University of Berlin , at
44426-436: Was a consultant to the Atomic Energy Research Establishment at Harwell. He received many awards, including a knighthood in 1968, and wrote several books including Quantum Theory of Solids , The Laws of Nature (1955), Surprises in Theoretical Physics (1979), More Surprises in Theoretical Physics (1991) and an autobiography, Bird of Passage (1985). Concerned with the nuclear weapons he had helped to unleash, he worked on
44655-435: Was a long device, and its name came from the Dashiell Hammett detective novel and series of movies of the same name. The Fat Man was round and fat, and was named after Sydney Greenstreet 's "Kasper Gutman" character in The Maltese Falcon . Little Boy came last, and was named after Elisha Cook, Jr. 's character in the same film, as referred to by Humphrey Bogart . A series of conferences in April and May 1943 laid out
44884-448: Was a spy for the Soviet Union. The article was based on information supplied by intelligence historian Nigel West , who identified Peierls as the spy codenamed "Fogel" and later "Pers" in the Venona intercepts, and his wife Genia as the spy codenamed "Tina". However, the association of Tina with Genia did not fit with what was known about Tina, and she was conclusively revealed to be Melita Norwood in 1999. Nor did Peierls fit Pers, as
45113-406: Was a strong indication of multiple allotropes of plutonium ; but was initially considered too bizarre to be true. Further testing confirmed a state change around 135 °C (275 °F); it entered the δ phase, with a density of 16 g/cm. Seaborg had claimed that plutonium had a melting point of around 950 to 1,000 °C (1,740 to 1,830 °F), about that of uranium, but the metallurgists at
45342-443: Was activated at Fort Sill, Oklahoma , on 17 April 1943. Its initial strength was just one officer and seven auxiliaries. The WAAC became the Women's Army Corps (WAC) on 24 August 1943, and the detachment became part of the 4817th Service Command Unit, with a strength of two officers and 43 enlisted women. They were sworn into the United States Army by Ashbridge. It reached a peak strength of about 260 women in August 1945. The WACs did
45571-573: Was already intimately familiar with the bomb design concepts. However, Oppenheimer had little administrative experience, and, unlike Urey, Lawrence, and Compton, had not won a Nobel Prize, which many scientists felt that the head of such an important laboratory should have. There were also concerns about Oppenheimer's security status, as many of his associates were communists , including his wife, Kitty ; his girlfriend, Jean Tatlock ; and his brother, Frank . A long conversation in October 1942 convinced Groves and Nichols that Oppenheimer thoroughly understood
45800-413: Was answerable directly to Groves, and was responsible for the township, government property and the military personnel. Four military units were assigned to the post. The MP Detachment, 4817th Service Command Unit, arrived from Fort Riley, Kansas , in April 1943. Its initial strength was 7 officers and 196 enlisted men; by December 1946 it had 9 officers and 486 men, and was manning 44 guard posts 24 hours
46029-427: Was best achieved through thermal diffusion , but as the difficulties with this approach became more apparent they switched to gaseous diffusion , bringing in a fellow refugee from Germany, Franz Simon , as an expert on the subject. Peierls also recruited yet another refugee from Germany, Klaus Fuchs , as his assistant in May 1941. As a result of the MAUD Committee's findings, a new directorate known as Tube Alloys
46258-462: Was carried out at Muroc Army Air Field in March and June 1944. At a meeting of the S-1 Executive Committee on 14 November 1942, Chadwick had expressed a fear that the alpha particles emitted by plutonium could produce neutrons in light elements present as impurities, which in turn would produce fission in the plutonium and cause a predetonation , a chain reaction before the core was fully assembled. This had been considered by Oppenheimer and Seaborg
46487-452: Was clear that the problem would be much more difficult from a theoretical and engineering perspective than the gun design. In July 1943, Oppenheimer wrote to John von Neumann, asking for his help, and suggesting that he visit Los Alamos where he could get "a better idea of this somewhat Buck Rogers project". Manhattan Project The Manhattan Project was a research and development program undertaken during World War II to produce
46716-434: Was considered to be the greatest teacher of theoretical physics. Fellow students there included Hans Bethe , Hermann Brück and William V. Houston . At the time, the Bohr-Sommerfeld theory was being overturned by the new quantum mechanics of Werner Heisenberg and Paul Dirac . In 1928, Sommerfeld set off on a world tour. On his advice, Peierls moved to the University of Leipzig , where Heisenberg had been appointed to
46945-509: Was created to coordinate the nuclear weapons development effort. Sir John Anderson , the Lord President of the Council , became the minister responsible, and Wallace Akers from Imperial Chemical Industries (ICI) was appointed the director of Tube Alloys. Peierls, Chadwick and Simon were appointed to its Technical Committee, which was chaired by Akers. Its first meeting, in November 1941, was attended by two American visitors, Harold Urey and George B. Pegram . Later that year, Peierls flew to
47174-427: Was created. Peierls delivered the lectures on quantum mechanics, a subject that had not been taught at Birmingham before the war. In 1946 Peierls became a consultant to the Atomic Energy Research Establishment at Harwell . After Fuchs was dismissed from his position there as head of the Theoretical Physics Division in 1950, Maurice Pryce acted in the position in a part-time capacity, but when he went to America for
47403-461: Was empowered to engage in research and large engineering projects. The NDRC Committee on Uranium became the S-1 Section of the OSRD; the word "uranium" was dropped for security reasons. In July 1941, Briggs proposed spending $ 167,000 on researching uranium, particularly the uranium-235 isotope, and plutonium , which had been isolated for the first time at the University of California in February 1941. In Britain, Frisch and Rudolf Peierls at
47632-402: Was engaged as architect and engineer. Black & Veatch was brought in for the design of utilities in December 1945. The former was paid $ 743,706.68 and the latter $ 164,116 by the time the Manhattan Project ended at the end of 1946. The Albuquerque District supervised $ 9.3 million of construction at Los Alamos, and the Manhattan District, another $ 30.4 million. The initial work was contracted to
47861-428: Was engaged in the K-25 Project , designing and building the American gaseous diffusion plant. While Kellex was located in the Woolworth Building , Peierls, Simon and Nicholas Kurti had their offices in the British supply mission on Wall Street . They were joined there by Tony Skyrme and Frank Kearton , who arrived in March 1944. Kurti returned to England in April 1944 and Kearton in September. Peierls moved on to
48090-440: Was for building and operating the plants that produced the fissile material . Research and production took place at more than 30 sites across the US, the UK, and Canada. The project resulted in two types of atomic bombs, developed concurrently during the war: a relatively simple gun-type fission weapon and a more complex implosion-type nuclear weapon . The Thin Man gun-type design proved impractical to use with plutonium , so
48319-453: Was given his own group, tasked with investigating Teller's "Super" bomb . Oppenheimer then wrote to the director of the Manhattan Project, Brigadier General Leslie R. Groves, Jr , requesting that Peierls be sent to take Teller's place in T Division. Peierls arrived from New York on 8 February 1944, and subsequently succeeded Chadwick as head of the British Mission at Los Alamos. Peierls also became leader of T-1 (Implosion) Group, and so
48548-401: Was his father's first wife, Elisabeth ( née Weigert). Rudolf had an older brother, Alfred, and an older sister, Annie. His mother died from Hodgkin's lymphoma in 1921, and his father married Else Hermann, the sister-in-law of the playwright Ludwig Fulda . The family was Jewish, but assimilated , and Peierls and his siblings were baptised as Lutherans . When he came of age, Peierls left
48777-430: Was ideal. Patterson approved the acquisition of the site on 25 November 1942, authorizing $ 440,000 for the purchase of pre-calculated 54,000 acres (22,000 ha), all but 8,900 acres (3,600 ha) of which were already owned by the Federal Government. Secretary of Agriculture Claude R. Wickard granted about 45,000 acres (18,000 ha) of United States Forest Service land to the War Department "for so long as
49006-542: Was just entering production, which could be adapted for use as a radar altimeter. The third unit to be made was delivered to Los Alamos in April 1944. In May it was tested by diving an AT-11 . This was followed by full-scale drop testing in June and July. These were very successful, whereas the AYD continued to suffer from problems. Archie was therefore adopted, although the scarcity of units in August 1944 precluded wholescale destructive testing. Testing of Silverplate Boeing B-29 Superfortress aircraft with Thin Man bomb shapes
49235-435: Was mostly drawn from the defunct Army Specialized Training Program . War Department policy forbade giving deferments from the draft to men under 22, so they were assigned to the SED. It reached a peak strength of 1,823 men in August 1945. SED personnel worked in all areas of the Los Alamos Laboratory. As director of the Los Alamos Laboratory, Oppenheimer was no longer answerable to Compton, but reported directly to Groves. He
49464-426: Was not completed until the autumn of 1944. John von Neumann visited the Los Alamos Laboratory in September 1943 and participated in discussions of the damage that an atomic bomb would do. He explained that while the damage done by a small explosion was proportional to the impulse (the average pressure of the explosion times its duration), the damage from large explosions such as an atomic bomb would be determined by
49693-522: Was not yet engaged in World War II , so Oliphant flew there in late August 1941, and spoke to American scientists including his friend Ernest Lawrence at the University of California . He not only managed to convince them that an atomic bomb was feasible, but inspired Lawrence to convert his 37-inch (94 cm) cyclotron into a giant mass spectrometer for isotope separation , a technique Oliphant had pioneered in 1934. In turn, Lawrence brought in his friend and colleague Robert Oppenheimer to double-check
49922-476: Was organized into five divisions: Administration (A), Theoretical (T) under Bethe, Experimental Physics (P) under Bacher, Chemistry and Metallurgy (CM) under Kennedy, and Ordnance and Engineering (E) under Parsons. All the divisions expanded during 1943 and 1944, but T Division, despite trebling in size, remained the smallest, while E Division grew to be the largest. Security clearance was a problem. Scientists (including, at first, Oppenheimer) had to be given access to
50151-443: Was put aside to concentrate on producing fission bombs. Teller raised the speculative possibility that an atomic bomb might "ignite" the atmosphere because of a hypothetical fusion reaction of nitrogen nuclei. Bethe calculated that it was "extremely unlikely". A postwar report co-authored by Teller concluded that "whatever the temperature to which a section of the atmosphere may be heated, no self-propagating chain of nuclear reactions
50380-408: Was reluctant to share its technological lead and help the United States develop its own atomic bomb. But the British, who had made significant advances in research early in the war, did not have the resources to carry through such a research program into development while a large portion of their economy was engaged in fighting the war; Tube Alloys soon fell behind its American counterpart. The roles of
50609-410: Was replaced by five Army telephone lines. This was increased to eight in March 1945. There were also three teletypewriters with encoding machines. The first was installed in March 1943, and two more were added in May 1943. One was removed in November 1945. There were telephones in the offices, but none in private residences, as the Army regarded this as a security hazard. There were some public phones in
50838-421: Was required. He spoke to Harvey Bundy and Generals Marshall, Somervell, and Styer about his concerns, advocating that the project be placed under a senior policy committee, with a prestigious officer, preferably Styer, as director. Somervell and Styer selected Groves for the post; General Marshall ordered that he be promoted to brigadier general, as it was felt that the title "general" would hold more sway with
51067-469: Was responsible for the design of the explosive lenses used in the implosion-type nuclear weapon to focus an explosion onto a spherical shape. He sent regular reports to Chadwick, the head of the British Mission to the Manhattan Project, in Washington, DC. When Groves found out, he asked Peierls to send him reports too. Peierls was one of those present at the Trinity nuclear test on 16 July 1945. He returned to England in January 1946. For his services to
51296-442: Was responsible for the technical and scientific aspects of Project Y. He assembled the nucleus of his staff from the groups that had been working for him on neutron calculations. These included his secretary, Priscilla Greene , Serber and McMillan from his own group, and Emilio Segrè and Joseph W. Kennedy 's groups from the University of California, J. H. Williams ' group from the University of Minnesota , Joe McKibben 's group from
51525-401: Was that it would be militarized when the time came to finally assemble the bomb, but by this time the Los Alamos Laboratory had grown so large that this was considered both impractical and unnecessary, as the anticipated difficulties regarding civilians working on dangerous tasks had not occurred. Colonel John M. Harman was the first post commander at Los Alamos. He joined the Santa Fe office as
51754-417: Was therefore a success; key American physicists were now aware of the potential power of an atomic bomb. On 9 October 1941, President Roosevelt approved the atomic program after he convened a meeting with Vannevar Bush and Vice President Henry A. Wallace . He created a Top Policy Group consisting of himself—although he never attended a meeting—Wallace, Bush, Conant, Secretary of War Henry L. Stimson , and
51983-412: Was to have been a military laboratory with Oppenheimer and other researchers commissioned into the Army, but Robert Bacher and Isidor Rabi balked at the idea and convinced Oppenheimer that other scientists would object. Conant, Groves, and Oppenheimer then devised a compromise whereby the laboratory was operated by the University of California under contract to the War Department. Dorothy McKibbin ran
52212-410: Was too close to a major population center (Knoxville) in the unlikely event of a major nuclear accident. Groves recruited DuPont in November 1942 to be the prime contractor for the construction of the plutonium production complex. The President of the company, Walter S. Carpenter Jr. , wanted no profit of any kind; for legal reasons a nominal fee of one dollar was agreed upon. DuPont recommended that
52441-410: Was used for Chicago Pile 3 , the first reactor using heavy water and natural uranium, which went critical on 15 May 1944. The Chalk River, Ontario , site was established to rehouse the Allied effort at the Montreal Laboratory away from an urban area. A new community was built at Deep River, Ontario , to provide residences and facilities for the team members. The site was chosen for its proximity to
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