Cockcroft Walton accelerator, 1930s.
© Science Museum / Science & Society Picture Library
In April 1932, J D Cockcroft (1897-1967) and E T S Walton performed an experiment which made Cockcroft's name in physics. After G Gamow (1904-1968) explained in 1928 how low-energy protons may tunnel out of a nucleus, Cockcroft realised that low-energy protons may also be able to tunnel in and cause disintegration of the nucleus. Using this accelerator, Cockcroft and Walton accelerated protons to the extent that they were able to disintegrate lithium nuclei.