Mark Oliphant

Sir Marcus "Mark" Laurence Elwin Oliphant, AC, KBE, FRS, FAA (8 October 1901 – 14 July 2000) was an Australian physicist and humanitarian who played an important role in the first experimental demonstration of nuclear fusion and also the development of nuclear weapons.

Born in Adelaide, South Australia, Oliphant graduated from the University of Adelaide in 1922. He was awarded an 1851 Exhibition Scholarship in 1927 on the strength of the research he had done on mercury, and went to England, where he studied under Sir Ernest Rutherford at the University of Cambridge's Cavendish Laboratory. There, he used a particle accelerator to fire heavy hydrogen nuclei (deuterons) at various targets. He discovered the nuclei of helium-3 (helions) and tritium (tritons). He also discovered that when they reacted with each other, the particles that were released had far more energy than they started with. Energy had been liberated from inside the nucleus, and he realised that this was a result of nuclear fusion.