November - December 2001

Engineering and Popular Culture:

Celebrating the Centennial of the Birth of
Engineer-Physicist Robert Van de Graaff
(20 December 1901 - 16 January 1967)

by Frederik Nebeker

Many, many engineers have made significant contributions to society during the course of their careers; at least as many scientists have done the same. Only a fraction of these groups, however, can claim they made strides and contributions in both engineering and science. Engineer-physicist Robert Van de Graaff is one of those few. Van de Graaff had both enviable engineering skill and a keen understanding of physics, making it possible for him to contribute to society through both disciplines.

Born in Tuscaloosa, Alabama in December 1901, Van de Graaff earned bachelor's and master's degrees in engineering from the University of Alabama. After a stint at Alabama Power Company, he studied physics at the Sorbonne and at Oxford, completing his PhD in 1928. By the next year, he had completed the first version of his eponymous electrostatic generator. With this generator, an electrically driven belt picked up charge at the base of a column and deposited charge on a spherical surface at the top of the column. With this generator, voltages as high as 20 megavolts could be achieved.

Source: MIT Library

Van de Graaff's primary motivation for this work was his interest in studying atoms; high voltage could be used to produce atomic probes in the form of accelerated electons, protons, and ions. Indeed, the generator served well in this capacity. What's more, when two, three or four generators were used in tandem, Van de Graaff and his colleagues could produce even higher energy protons.

But the Van de Graaff generator turned out to have practical applications that went well beyond studying atoms.

After moving from Princeton to MIT in 1931, Van de Graaff adapted his generator to produce high-energy 
x-rays for treating deep-seated tumors. The first 1-MeV unit was installed at Huntington Memorial Hospital in Boston in 1937.

Then, during World War II, he helped design an x-ray machine that the U.S. Navy used to search for defects during the manufacture of large guns. After the war he co-founded the High Voltage Engineering Corporation (HVEC) to manufacture and sell his generator, which continued to find other uses. For example, in addition to cancer treatment and industrial radiology, the device had sterilization and polymerization applications as well.

Always searching for ways to achieve ever-higher voltages, in the 1950s Van de Graaff found that he could do this by using magnetic flux with his insulating-core transformer, rather than the traditional electrostatic charging, This newer "invention" has been applied in industry as a source of high-energy electrons and has been used for power-factor correction in high-voltage power transmission.

In 1960 Van de Graaff left MIT to work full-time at HVEC. And there he remained until he died in January 1967.

Frederik Nebeker is Senior Research Historian at the IEEE History Center at Rutgers University. Visit the IEEE History Center's Web page at: www.ieee.org/organizations/history_center/.