page_title: MAUD Committee
section_title: University of Cambridge
hierarchical_section_title: MAUD Committee / Activity / University of Cambridge
caption_attribution_description: English: The Cavendish Laboratory The Cavendish Laboratory was the home of some of the great discoveries in physics. It was founded in 1874 by the Duke of Devonshire (Cavendish was his family name), when its first professor was James Clerk Maxwell. In 1974 the department moved to new premises.
context_page_description: The MAUD Committee was a British scientific working group formed during the Second World War. It was established to perform the research required to determine if an atomic bomb was feasible. The name MAUD came from a strange line in a telegram from Danish physicist Niels Bohr referring to his housekeeper, Maud Ray.
  The MAUD Committee was founded in response to the Frisch-Peierls memorandum, which was written in March 1940 by Rudolf Peierls and Otto Frisch, two physicists who were refugees from Nazi Germany working at the University of Birmingham under the direction of Mark Oliphant. The memorandum argued that a small sphere of pure uranium-235 could have the explosive power of thousands of tons of TNT.
  The chairman of the MAUD Committee was George Thomson. Research was split among four different universities: the University of Birmingham, University of Liverpool, University of Cambridge and the University of Oxford, each having a separate programme director. Various means of uranium enrichment were examined, as was nuclear reactor design, the properties of uranium-235, the use of the then-hypothetical element plutonium, and theoretical aspects of nuclear weapon design.
context_section_description: The division of the MAUD Committee at Cambridge was jointly led by Bragg and Cockcroft. It included Brestscher, Feather, Halban, Kowarski, Herbert Freundlich and Nicholas Kemmer. Paul Dirac assisted as a consultant, although he was not formally part of the team. On 19 June 1940, following the German invasion of France, Halban, Kowarski and other French scientists and their families, along with their precious stock of heavy water, were brought to England by the Earl of Suffolk and Major Ardale Golding on the steamer Broompark. The heavy water, valued at £22,000, was initially kept at HM Prison Wormwood Scrubs, but was later secretly stored in the library at Windsor Castle. The French scientists moved to Cambridge, where they conducted experiments that conclusively showed that a nuclear chain reaction could be produced in a mixture of uranium oxide and heavy water.
  In a paper written shortly after they arrived in England, Halban and Kowarski theorised that slow neutrons could be absorbed by uranium-238, forming uranium-239. A letter by Edwin McMillan and Philip Abelson published in the Physical Review on 15 June 1940 stated that this decayed to an element with an atomic number of 93, and then to one with an atomic number of 94 and mass of 239, which, while still radioactive, was fairly long-lived. That a letter on such a sensitive subject could still be published irked Chadwick, and he asked for an official protest to be sent to the Americans, which was done.
  Bretscher and Feather argued, on theoretical grounds, that this element might be capable of fission by both fast and slow neutrons like uranium-235. If so, this promised another path to an atomic bomb, as it could be bred from the more abundant uranium-238 in a nuclear reactor, and separation from uranium could be by chemical means, as it was a different element, thereby avoiding the necessity for isotope separation. Kemmer suggested that since uranium was named after the planet Uranus, element 93 could be named neptunium and 94 plutonium after the next two planets. Later it was discovered that the Americans had independently adopted the same names, following the same logic. Bretscher and Feather went further, theorising that irradiation of thorium could produce a new isotope of uranium, uranium-233, which might also be susceptible to fission by both fast and slow neutrons. In addition to this work, Eric Rideal studied isotope separation through centrifugation.
caption: The Cavendish Laboratory at the University of Cambridge
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