Marcus Laurence Elwin Oliphant (born 8.10.1901) is an Australian physicist and a member of the Australian Academy of Science, of which he was president in 1954 — 57. He was born in Adelaide. He graduated from the universities of Adelaide (1927) and Cambridge (1929), and worked at the latter until 1937 (in 1935 as E. Rutherford's deputy at the Cavendish Laboratory); in 1937 —50 he was professor and director of the physics department of the University of Birmingham. In 1950 — 70 he was at the Australian National University (Canberra), where in 1950 — 63 he was director of the Physical Institute and (1950 — 64) professor.
His research concerned nuclear physics, electrical discharges in gases, accelerator technology and high-energy physics. In 1933, together with E. Rutherford, he confirmed the validity of the law relating mass and energy for nuclear processes. He discovered two new isotopes of hydrogen and helium, tritium and 3He, and reactions with deuterium that are fundamental to thermonuclear fusion. He proposed (1943) the idea of using a ring magnet to accelerate charged particles to high energies, and, independently of others, the synchrotron (1947).
A Fellow of the Royal Society (1937). The D. Hughes (1943) and M. Faraday (1948) medals.