In 1932 the physicists John Cockcroft and Ernest Walton, at the Cavendish Laboratory in Cambridge, devised a technique for bombarding atomic nuclei with protons (hydrogen nuclei) that had been accelerated in a powerful electric field. The aim of these attempts to 'split the atom' was to explore the basic composition of matter.

These experiments showed that the atomic nucleus was not an indivisible and basic unit, but had its own internal structure. This structure included the newly-revealed sub-atomic particles which were 'broken out' of the nucleus by these experiments. This growing understanding of atomic structure and of atomic disintegration led during the 1930s directly to ideas for the atomic bomb and for atomic power.

The machine shown here is the cascade generator, built by Philips of Eindhoven, and designed to produce the high voltage (up to 1.25 million volts) required to accelerate the particles. During the Second World War the machine was used to investigate the properties of uranium and plutonium as a contribution to the Manhattan Project which manufactured the first atomic bombs.

Inv. 1982-1318