Robert J. Van de Graaff
Robert J. Van de Graaff | |
---|---|
Tom W. Bonner Prize in Nuclear Physics (1966) | |
Scientific career | |
Fields | Physics |
Institutions | Massachusetts Institute of Technology Princeton University |
Doctoral advisor | John Sealy Townsend |
Robert Jemison Van de Graaff (December 20, 1901 – January 16, 1967) was an American physicist, noted for his design and construction of high-voltage Van de Graaff generators. He spent most of his career in the Massachusetts Institute of Technology (MIT).[1]
Biography
Robert Jemison
His three older brothers
After a year working for the
Van de Graaff was the inventor of the Van de Graaff generator, a device which produces high voltages. During 1929, he developed his first such generator, producing 80,000 volts.[6] By 1933, he had constructed a larger generator generating 7 million volts.[6]
Van de Graaff spent 1929-1931 at Princeton, became a National Research Fellow, and from 1931 to 1934 a research associate of the Massachusetts Institute of Technology. He became an associate professor in 1934 (staying there until 1960). He was awarded the Elliott Cresson Medal in 1936.
During World War II, Van de Graaff was director of the High Voltage Radiographic Project. After World War II, he co-initiated the High Voltage Engineering Corporation (HVEC) with John G. Trump. During the 1950s he invented the insulating-core transformer, producing high-voltage direct current. He also developed tandem generator technology.
The
Van de Graaff died on January 16, 1967, in Boston, Massachusetts.
In the year that he died, the progressive rock band Van der Graaf Generator was formed, named after him, notwithstanding the spelling errors. The Van de Graaff crater on the far side of the Moon is named after him.
Van de Graaff generator
Van de Graaff generators use a motorized insulating belt (usually made of rubber) to conduct electrical charges from a high voltage source on one end of the belt to the inside of a metal sphere on the other end. Since electrical charge resides on the outside of the sphere, it accumulates to produce an electrical potential much greater than that of the primary high voltage source. Practical limitations restrict the potential produced by large Van de Graaff generators to about 7 MV. Van de Graaff generators are used primarily as DC power supplies for linear atomic particle accelerators used for nuclear physics experiments. Tandem Van de Graaff generators are essentially two generators in series and can produce about 15 MV.
The Van de Graaff generator is a simple mechanical device. Small Van de Graaff generators are built by hobbyists and scientific apparatus companies and are used to demonstrate the effects of high DC potentials. Even small hobby machines produce impressive sparks several centimeters long. The largest air-insulated Van de Graaff generator in the world, built by Van de Graaff himself, is operational and is on display in the
Patents
- US1,991,236 – "Electrostatic Generator"
- US2,024,957 – "Electrical Transmission System"
- US2922905[permanent dead link] — "Apparatus For Reducing Electron Loading In Positive-Ion Accelerators"
- US3,187,208 – "High Voltage Electromagnetic Apparatus Having An Insulating Magnetic Core"
- US3,323,069 – "High Voltage Electromagnetic Charged-Particle Accelerator Apparatus Having An Insulating Magnetic Core"
- US3239702[permanent dead link] — "Multi-Disk Electromagnetic Power Machinery"
- US3,308,323 – "Inclined field High Voltage Vacuum Tubes"
References
- ^ "Van de Graaf, Robert Jemison, 1901-1967". American Institute of Physics. Niels Bohr Library. Archived from the original on 2023-04-08.
- ^ Ben Windham. "SOUTHERN LIGHTS: Robert Van de Graaff never received his due in Tuscaloosa". Tuscaloosa News. Archived from the original on September 3, 2013. Retrieved November 6, 2014.
- ^ "Van de Graaff History". Jemison-Van de Graaff Mansion (official website). Archived from the original on February 6, 2009. Retrieved 10 July 2010.
- ^ "Chapter History". muthetatau.org. Retrieved 23 July 2015.
- ^ "February 12, 1935: Patent granted for Van de Graaff generator". APS News. February 2011.
- ^ a b "Robert Jemison Van de Graaff was born on December 20, 1901 in Tuscaloosa, Alabama". Archived from the original on October 24, 2017. Retrieved August 23, 2004.
External links
- Media related to Robert Van de Graaff at Wikimedia Commons
- Robert J. Van de Graaff at the Mathematics Genealogy Project
- Robert J. Van de Graaff at Find a Grave