 Oliphant left the Cavendish Laboratory in 1937 to become the Poynting Professor of Physics at the University of Birmingham . He attempted to build a 60 @-@ inch ( 150 cm ) cyclotron at the university , but its completion was postponed by the outbreak of the Second World War in Europe in 1939 . He became involved with the development of radar , heading a group at the University of Birmingham that included John Randall and Harry Boot . They created a radical new design , the cavity magnetron , that made microwave radar possible . Oliphant also formed part of the MAUD Committee , which reported in July 1941 , that an atomic bomb was not only feasible , but might be produced as early as 1943 . Oliphant was instrumental in spreading the word of this finding in the United States , thereby starting what became the Manhattan Project . Later in the war , he worked on it with his friend Ernest Lawrence at the Radiation Laboratory in Berkeley , California , developing electromagnetic isotope separation . 
