Philips Cockcroft Walton accelerator, c 1940.
© Science Museum / Science & Society Picture Library
This accelerator was built for the Cavendish Laboratory, Cambridge, UK, by Philips of Eindhoven. The design is based on the earlier Cockcroft Walton accelerator of 1932, which John Cockcroft (1897-1967) and Ernest Walton used to disintegrate lithium nuclei. In 1932, G Gamow (1904-1968) explained how a particle may escape from a nucleus by tunnelling through the barrier that held it in. Cockcroft realised that the opposite proces may occur, and particles tunnel into nuclei to cause disintegration. (Copyright must be cleared with the Cavendish Laboratory, Cambridge.)