Robert J. Van de Graaff

Robert Jemison Van de Graaff (December 20, 1901 – January 16, 1967) was an American applied physicist and inventor. He is best known for developing the Van de Graaff generator, a high-voltage electrostatic machine that became a fundamental tool in nuclear physics research.

Raised in Tuscaloosa, Alabama, Van de Graaff earned his DPhil degree at Oxford as a Rhodes Scholar. In Europe, exposure to Marie Curie, Ernest Rutherford, and J. Robert Oppenheimer encouraged him to develop methods for accelerating particles to nuclear energies. He built his first electrostatic generator at Princeton University in 1929 and demonstrated a 1.5-million-volt model in 1931, more than twice the highest direct current voltage previously achieved. After joining the Massachusetts Institute of Technology he constructed the 5-megavolt Round Hill generator. He collaborated with John G. Trump, his former student, on creating compact, gas-insulated machines, which became the first accelerators used in clinical medicine. During World War II, he directed development of high-voltage X-ray equipment for the U.S. Navy.

A high school football injury, aggravated by wartime overwork and later accidents, left Van de Graaff with chronic health problems in his later career. Nevertheless, in 1946 he joined Trump and Denis M. Robinson in organizing the High Voltage Engineering Corporation, the first company to manufacture particle accelerators. As Chief Scientist, he guided development of commercial accelerators. In the 1950s, he invented the insulating-core transformer and was instrumental in commercializing HVEC's tandem accelerators. By 1967, more than 500 high-voltage Van de Graaff generators were operating worldwide, and HVEC had installed accelerators in hospitals and labs in 30 countries. He received the Tom W. Bonner Prize in 1966 for his contributions to electrostatic accelerator development.