John Cockcroft - Nuclear Research

Nuclear Research

In 1928, he began to work on the acceleration of protons with Ernest Walton. In 1932, they bombarded lithium with high energy neutrons, electrons and protons and succeeded in transmuting it into helium and other chemical elements. This was one of the earliest experiments to change the atomic nucleus of one element to a different nucleus by artificial means. This feat was popularly – if somewhat inaccurately – known as splitting the atom.

At the outbreak of the Second World War, he took up the post of Assistant Director of Scientific Research in the Ministry of Supply, working on radar. In 1944, he took charge of the Canadian Atomic Energy project and became Director of the Montreal Laboratory and Chalk River Laboratories, replacing Hans von Halban, who was considered a security risk. In 1946, he returned to Britain to set up the Atomic Energy Research Establishment (AERE) at Harwell, charged with developing Britain's atomic power programme. He became the first director of AERE. Even when leaving the post, he continued to be involved with Harwell. He was made a Commander of the Order of the British Empire in 1944, knighted in 1948, and created Knight Commander of the Order of the Bath in 1953.

As director of the AERE, he famously insisted that the coolant discharge chimney stacks of the Windscale plutonium production reactors be fitted, at great expense, with high performance filters. Since this was decided after the stacks had been designed, they produced iconic lumps in the shape of the structures. The reactors were designed to remain clean and uncorroded during use, thus it was not considered that there would be any particulate present for the filters to catch. These filters were therefore known as "Cockcroft's Folly" until the core of one of the two reactors caught fire in 1957, and the filters prevented the disaster from becoming a catastrophe.

In post-war years, AERE under his direction took part in frontier fusion research, including the ZETA program.