van de Graaff, Robert Jemison (1901–1967)

US physicist who from 1929 developed a high-voltage generator, which in its modern form can produce more than a million volts.

Van de Graaff was born in Tuscaloosa, Alabama, and studied at the University of Alabama, in France at the Sorbonne, and in the UK at Oxford. He worked at the Massachusetts Institute of Technology 1931–60. In 1946 he set up the High Voltage Engineering Corporation with his collaborator John Trump.

Trump and van de Graaff had modified the generator so that it would produce hard X-rays for use in radiotherapy in treating internal tumours (the first machine was installed in a Boston hospital 1937). In the 1940s they began commercial production, and developed the van de Graaff generator for a wide variety of scientific, medical, and industrial research purposes. The tandem principle of particle acceleration and a new insulating core transformer invented by van de Graaff contributed to these advances.