What American engineer and physicist taught at Princeton University and Massachusetts Institute of Technology and developed one of the first million-volt X-ray generators with John G. Trump?
John G. Trump: John George Trump (August 21, 1907 – February 21, 1985) was an American electrical engineer, inventor, and physicist. John G. Trump:  Together with Robert J. Van de Graaff, he developed one of the first million-volt X-ray generators. Robert J. Van de Graaff: Robert Jemison Van de Graaff (December 20, 1901 – January 16, 1967) was an American engineer, physicist, and noted for his design and construction of high-voltage Van de Graaff generators. Robert J. Van de Graaff:  He taught at Princeton University and Massachusetts Institute of Technology.
Robert J. Van de Graaff