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Home , Edwin McMillan, John Randall (physicist), Mark Oliphant, Maud Committee

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Obituary here, despite the fact that the report of the Mark Oliphant (1901–2000) MAUD Committee had been sent to the relevant authorities. He immediately informed a few influential friends about The Australian physicist Sir Marcus the British findings. The outcome of Laurence Elwin Oliphant, who died on Oliphant’s indiscretion was the setting up 14 July 2000, was the last of the of the Manhattan Project. He himself ‘Rutherford Boys’ — the brilliant team worked on the project, on the manufacture

who, under the leadership of Lord of uranium-235, in California and BOB COOPER, ANU Rutherford, made the Cavendish Tennessee. Laboratory in Cambridge the Mecca of Oliphant returned to Birmingham for nuclear research during the years between only a few years before taking up, in 1950, the two world wars. A figure larger than permanent residence in his native country. life, Oliphant exuded physical vitality and During his time in Birmingham he self-confidence. A genial extrovert, with a designed the proton-synchrotron, in booming laugh, he spoke his mind bluntly, which particles could be accelerated to never shy of challenging authority. As a gigaelectronvolts (GeV). This work was scientist he was imaginative and creative; based on the ‘phase stability’ principle, as a public figure he had a strong which he conceived before Vladimir commitment to freedom of speech and an Veksler and Edwin McMillan. abhorrence of secrecy in any walk of life. Oliphant was lured to Canberra by a Oliphant joined the Cavendish promise from the Australian government Laboratory in 1927, on an 1851 Exhibition to provide him with sufficient finances Scholarship. He quickly endeared himself to set up a Research School of Physical to Rutherford by his experimental skill. Sciences at the new Australian National Making things with one’s own hands was Enthusiastic builder of University. With his usual enthusiasm he in the Cavendish tradition of ‘sealing-wax particle accelerators threw himself into the project of creating and string’, but Oliphant was also an a school of nuclear research equal to any enthusiast for new technologies, with a and research centres in the world; this included a plan for an penchant for building particle accelerators. accelerator of novel design that would Improving on the Cockcroft–Walton Oliphant’s department, soon developed a produce particles with a higher energy accelerator by designing ion sources of much more efficient device, the resonant than achieved anywhere else. Although much greater intensity, Oliphant’s main cavity magnetron. Within a few months much of his planning came to fruition, contributions were the study of the nuclear it became the tool that helped to win the he failed to build his ambitious 10-Gev reactions that occurred when deuterium Battle of Britain in 1940 and avert Hitler’s ‘cyclosynchrotron’; it was simply beyond was bombarded with deuterons, which led invasion of England. It was largely the capacity of a small country, and his to the discovery of tritium. Considering his Oliphant’s indefatigability that made dream machine remained a “white later anti-nuclear campaigns, it is ironic this possible. Oliphant” (as it was described at the time). that the main practical applications of his Oliphant played a somewhat similar However, this failure did not diminish his work should be in nuclear weapons — role in the development of the atom bomb. high standing in Australia — he had the tritium is a booster for the fission bomb, Research on the bomb began in England in unique distinction, for a scientist, of and the fusion reactions are the basis of the 1939, but the main impetus came from the serving as a governor of South Australia, hydrogen bomb. calculations by Otto Frisch and Rudolf the state of his birth. After moving to Birmingham in 1937, Peierls, early in 1940, which showed that Oliphant was vehemently opposed to Oliphant took on the task of converting a the critical mass for a divergent chain the use of the atom bomb on the Japanese moribund physics department into a reaction, propagated by fast neutrons in cities. He never overcame his feelings of leading nuclear research centre. He saw to uranium-235, was only a few kilograms. guilt about his part in the Manhattan this by building a 60-inch cyclotron, the It was Oliphant who brought the Project, and he frequently expressed his largest at the time in England. However, Frisch–Peierls memorandum to the views to the Australian media. He also the completion of the machine was attention of government authorities. took an active part in international interrupted by the outbreak of the Second As a result, the MAUD Committee was campaigns against nuclear weapons, World War in 1939. Two projects more set up, charged with the development of particularly in the Pugwash Conferences urgent and vital to the war effort — radar the atom bomb. on Science and World Affairs. One of the and the atom bomb — were to occupy his Most of the experimental research 22 participants in the first conference in mind for the next six years. on the physics of the bomb was done in 1957, he fully shared the Pugwash precept To make a radar that would be of Liverpool, where Frisch joined James that scientists have a moral duty to be practical use in the war — for example, Chadwick’s team. By 1941, the scientific concerned about the social impact of their as a means of detecting approaching feasibility of the bomb had been work. Describing himself as a ‘belligerent enemy aircraft — it was necessary to established, but the separation of the pacifist’, he advocated his conviction that increase greatly the power in the radio uranium-235 isotope was too difficult a war itself is evil and must not be tolerated beam and to make it work at much shorter task for Britain under wartime conditions. by humanity. Joseph Rotblat wavelengths. Oliphant adapted the While on a trip to the United States on Joseph Rotblat is at the Pugwash Conferences on klystron (used as a radiofrequency source business connected with radar, in the Science and World Affairs, 63A Great Russell Street, in the cyclotron) for this purpose. But autumn of 1941, Oliphant discovered that London WC1B 3BJ, UK. John Randall and Harry Boot, working in no work on the atom bomb was going on t e-mail: [email protected]