John Cockcroft

John Cockcroft was a British physicist and engineer who became one of the founding figures of Britain's civilian nuclear power program. In 1932, working with Ernest Walton at the Cavendish Laboratory in Cambridge, he built the first accelerator to artificially split an atomic nucleus, a demonstration popularly called splitting the atom that won the pair the 1951 Nobel Prize in Physics. After the Second World War Cockcroft became the first director of the Atomic Energy Research Establishment at Harwell, where the low-powered GLEEP reactor he oversaw became the first nuclear reactor to operate in Western Europe when it started up on 15 August 1947. He also insisted on fitting expensive filters to the chimneys of the Windscale reactors, a precaution mocked at the time as Cockcroft's Folly, which caught much of the radioactive release during the 1957 Windscale fire and prevented a far worse contamination event.