Professor James Chadwick, c mid-20th century

Sir James Chadwick, born 20 October 1891, died 24 July 1974, was an English nuclear physicist, who is best known for his discovery of the neutron, which won him the 1935 Nobel Prize in Physics. He also wrote the final draft of the MAUD Report, which inspired serious efforts towards the atomic bomb. He headed the British team working on the Manhattan Project during WWII. Chadwick studied at the University of Manchester, graduating in 1911, where he had studied under Ernest Rutherford, obtaining an MSc in 1913. As he was in Germany when WWI began, studying in Berlin with Hans Geiger, he spent four years in Ruhleben Interment Camp. After WWI, he worked at Cavendish Laboratory, Cambridge, where he obtained his PhD in 1921. In 1925, Chadwick married Aileen Stewart-Brown, and had twin daughters. Chadwick discovered the neutron in 1932, for which he was given the Hughes Medal of the Royal Society (1932), the Nobel Prize in Physics (1935), the Copley Medal (1950), and the Franklin Medal (1951). During WWII, he carried out research as part of the Tube Alloys project to build an atomic bomb, and then on to the Manhattan Project after the projects merged to make an Allied effort. Chadwick was knighted in 1945 for his achievements in nuclear physics. In 1948, Chadwick became the Master of Gonville and Caius College, during which the structure of DNA was discovered at the college. Chadwick worked there until his retirement in 1958. Chadwick died in 1974, aged 82.