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Robert Jemison Van de Graaff (December 20, 1901 – January 16, 1967) was an American
physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...
, noted for his design and construction of high-voltage
Van de Graaff generator A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column, creating very high electric potentials. It produces very high voltage dir ...
s. The bulk of his career was spent in the Massachusetts Institute of Technology.


Biography

Robert Jemison
Van A van is a type of road vehicle used for transporting goods or people. Depending on the type of van, it can be bigger or smaller than a pickup truck and SUV, and bigger than a common car. There is some varying in the scope of the word across ...
de Graaff was born in the Jemison-Van de Graaff Mansion in
Tuscaloosa, Alabama Tuscaloosa ( ) is a city in and the seat of Tuscaloosa County in west-central Alabama, United States, on the Black Warrior River where the Gulf Coastal and Piedmont plains meet. Alabama's fifth-largest city, it had an estimated population of ...
to Adrian Sebastian "Bass" Van de Graaff and Minnie Cherokee Jemison. Robert's great grandfather was
Robert Jemison Jr The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of '' Hruod'' ( non, Hróðr) "fame, glory, honou ...
. His father Adrian was a circuit judge who had been a substitute on
Yale University Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the w ...
's football team of
1880 Events January–March * January 22 – Toowong State School is founded in Queensland, Australia. * January – The international White slave trade affair scandal in Brussels is exposed and attracts international infamy. * February � ...
. His father was of
Dutch Dutch commonly refers to: * Something of, from, or related to the Netherlands * Dutch people () * Dutch language () Dutch may also refer to: Places * Dutch, West Virginia, a community in the United States * Pennsylvania Dutch Country People ...
descent. His three older brothers Adrian, Jr., Hargrove, and
William William is a male Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male organism cannot reproduce sex ...
were all All-Southern
college football College football (french: Football universitaire) refers to gridiron football played by teams of student athletes. It was through college football play that American football rules first gained popularity in the United States. Unlike most o ...
players for the
Alabama Crimson Tide The Alabama Crimson Tide refers to the intercollegiate athletic varsity teams that represent the University of Alabama, located in Tuscaloosa. The Crimson Tide teams compete in the National Collegiate Athletic Association's Division I as a mem ...
. William was known as "Bully" and was Alabama's first
All-America The All-America designation is an annual honor bestowed upon an amateur sports person from the United States who is considered to be one of the best amateurs in their sport. Individuals receiving this distinction are typically added to an All-Am ...
n. In Tuscaloosa, Robert received his B.S. in mathematics (1922) and M.S. in mechanical engineering (1923) from The University of Alabama where he was a member of The Castle Club (later became Mu Chapter of
Theta Tau Theta Tau () is a professional engineering fraternity. The fraternity has programs to promote the social, academic, and professional development of its members. Today, Theta Tau is the oldest and largest professional engineering fraternity and h ...
). After a year working for the Alabama Power Company, Van de Graaff attended the Marie Curie lectures at the Sorbonne in 1925. During 1926, he earned a second B.S. at Oxford University by a
Rhodes Scholarship The Rhodes Scholarship is an international postgraduate award for students to study at the University of Oxford, in the United Kingdom. Established in 1902, it is the oldest graduate scholarship in the world. It is considered among the world' ...
, completing his D.Phil. under John Sealy Townsend at
Oxford University Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the ...
in 1928. Van de Graaff was the inventor of the
Van de Graaff generator A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column, creating very high electric potentials. It produces very high voltage dir ...
, a device which produces
high voltage High voltage electricity refers to electrical potential large enough to cause injury or damage. In certain industries, ''high voltage'' refers to voltage above a certain threshold. Equipment and conductors that carry high voltage warrant spe ...
s. During 1929, he developed his first such generator, producing 80,000 volts. By 1933, he had constructed a larger generator generating 7 million volts. 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 The Massachusetts Institute of Technology (MIT) is a Private university, private Land-grant university, land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern t ...
. He became an associate professor in 1934 (staying there until 1960). He was awarded the
Elliott Cresson Medal The Elliott Cresson Medal, also known as the Elliott Cresson Gold Medal, was the highest award given by the Franklin Institute. The award was established by Elliott Cresson, life member of the Franklin Institute, with $1,000 granted in 1848. The ...
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 John George Trump (August 21, 1907 – February 21, 1985) was an American electrical engineer, inventor, and physicist. A professor at the Massachusetts Institute of Technology from 1936 to 1973, he was a recipient of the National Medal of Scie ...
. During the 1950s he invented the insulating-core
transformer A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's ...
, producing high-voltage direct current. He also developed
tandem Tandem, or in tandem, is an arrangement in which a team of machines, animals or people are lined up one behind another, all facing in the same direction. The original use of the term in English was in ''tandem harness'', which is used for two ...
generator technology. The
American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of k ...
awarded him the T. Bonner prize (1965) for the development of electrostatic accelerators. Van de Graaff died on January 16, 1967, in
Boston Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- m ...
,
Massachusetts Massachusetts (Massachusett: ''Muhsachuweesut Massachusett_writing_systems.html" ;"title="nowiki/> məhswatʃəwiːsət.html" ;"title="Massachusett writing systems">məhswatʃəwiːsət">Massachusett writing systems">məhswatʃəwiːsət'' En ...
. In the year that he died, the progressive rock band
Van der Graaf Generator Van der Graaf Generator are an English progressive rock band, formed in 1967 in Manchester by singer-songwriters Peter Hammill and Chris Judge Smith and the first act signed by Charisma Records. They did not experience much commercial succe ...
was formed, named after him, notwithstanding the spelling errors. Furthermore, a
crater Crater may refer to: Landforms *Impact crater, a depression caused by two celestial bodies impacting each other, such as a meteorite hitting a planet *Explosion crater, a hole formed in the ground produced by an explosion near or below the surfac ...
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
Boston Museum of Science The Museum of Science (MoS) is a science museum and indoor zoo in Boston, Massachusetts, located in Science Park, a plot of land spanning the Charles River. Along with over 700 interactive exhibits, the museum features a number of live presentat ...
. Demonstrations during daytimes are a popular attraction. More modern Van de Graaff generators are insulated by pressurized dielectric gas, usually
freon Freon ( ) is a registered trademark of the Chemours Company and generic descriptor for a number of halocarbon products. They are stable, nonflammable, low toxicity gases or liquids which have generally been used as refrigerants and as aerosol pr ...
or
sulfur hexafluoride Sulfur hexafluoride or sulphur hexafluoride ( British spelling) is an inorganic compound with the formula SF6. It is a colorless, odorless, non-flammable, and non-toxic gas. has an octahedral geometry, consisting of six fluorine atoms attached ...
. During recent years, Van de Graaff generators have been slowly replaced by solid-state DC power supplies without moving parts. The energies produced by Van de Graaff atomic
particle accelerator A particle accelerator is a machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams. Large accelerators are used for fundamental research in particle ...
s are limited to about 30 MeV, even with tandem generators accelerating doubly charged (for example alpha) particles. More modern particle accelerators using different technology produce much greater energies, thus Van de Graaff particle accelerators have become largely obsolete. They are still used to some extent for graduate student research at colleges and universities and as ion sources for high energy bursts.


Patents

* – "''Electrostatic Generator''" * – "''Electrical Transmission System''"
US2922905
— "''Apparatus For Reducing Electron Loading In Positive-Ion Accelerators''" * – "''High Voltage Electromagnetic Apparatus Having An Insulating Magnetic Core''" * – "''High Voltage Electromagnetic Charged-Particle Accelerator Apparatus Having An Insulating Magnetic Core''"

— "''Multi-Disk Electromagnetic Power Machinery''" * – "''Inclined field High Voltage Vacuum Tubes''"


References


External links

* * * {{DEFAULTSORT:Van De Graaff, Robert J. 1901 births 1967 deaths American Rhodes Scholars American people of Dutch descent People from Tuscaloosa, Alabama 20th-century American physicists Alumni of The Queen's College, Oxford University of Alabama alumni University of Alabama people Princeton University faculty Massachusetts Institute of Technology School of Science faculty American scientific instrument makers Fellows of the American Physical Society