Editing Robert J. Van de Graaff

{{Short description|American physicist (1901–1967)}}
{{family name hatnote|Van de Graaff|Graaff|lang=Dutch}}
{{Infobox scientist
|name              = Robert J. Van de Graaff
|image             = Robert Van de Graaff.jpg
|caption           = Honorary doctorate Utrecht University, 19 April 1966
|birth_name=Robert Jemison Van de Graaff
|birth_date        = {{Birth date|1901|12|20}}
|birth_place       = [[Tuscaloosa, Alabama]], U.S.
|death_date        = {{Death date and age|1967|1|16|1901|12|20}}
|death_place       = [[Boston, Massachusetts]], U.S.
|residence         = 
|field             = [[Physics]]
|work_institutions = [[Massachusetts Institute of Technology]]<br>[[Princeton University]]
|alma_mater        = [[University of Alabama]] (B.S.; M.S.)<br>[[La Sorbonne]]<br>[[University of Oxford]] (B.S.; D.Phil.)
|thesis_title      = I. Ionization of Hydrogen and Nitrogen; II. Velocities of Ions and Electrons in Gases under a Constant Electric Force
|thesis_url        = 
|thesis_year       = 1928
|doctoral_advisor  = [[John Sealy Townsend]]
|doctoral_students = [[John G. Trump]]
|known_for         = [[Van de Graaff generator]]
|influences        = 
|influenced        = 
|prizes            = [[Elliott Cresson Medal]] <small>(1936)</small><br>[[Duddell Medal and Prize]] <small>(1947)</small><br>[[Tom W. Bonner Prize in Nuclear Physics]] <small>(1966)</small>
|footnotes         = 
|signature         =
}}

[[File:Utrecht1966.jpg|upright=1.35|thumb|Robert Van de Graaff (left) at [[Utrecht University]] in 1966]]

'''Robert Jemison Van de Graaff'''<!-- NOT "van de" or "Van Der". See on google or good refs --> (December 20, 1901 – January 16, 1967) was an American [[physicist]], noted for his design and construction of high-voltage [[Van de Graaff generator]]s. He spent most of his career in the [[Massachusetts Institute of Technology]] (MIT).<ref>{{cite web |url=https://history.aip.org/phn/11610027.html |archive-url=https://web.archive.org/web/20230408094014/https://history.aip.org/phn/11610027.html |archive-date=2023-04-08 |title=Van de Graaf, Robert Jemison, 1901-1967 |location=Niels Bohr Library |website=American Institute of Physics}}</ref>

==Biography==
Robert Jemison [[Van (Dutch)|Van]] de Graaff was born in the [[Jemison-Van de Graaff Mansion]] in [[Tuscaloosa, Alabama]], to Adrian Sebastian "Bass" Van de Graaff and Minnie Cherokee Jemison. Robert's great grandfather was [[Robert Jemison Jr.|Robert Jemison Jr]]. His father Adrian was a circuit judge.<ref>{{cite news|url=http://bama.ua.edu/~jharrell/PH106-S06/vandegraaff.htm|title=SOUTHERN LIGHTS: Robert Van de Graaff never received his due in Tuscaloosa|work=Tuscaloosa News|author=Ben Windham|access-date=November 6, 2014|archive-url=https://web.archive.org/web/20130903014526/http://bama.ua.edu/~jharrell/PH106-S06/vandegraaff.htm|archive-date=September 3, 2013|url-status=dead}}</ref> His father was of [[Dutch (ethnic group)|Dutch]] descent.<ref name="jemisonmansion">{{cite web|url=http://www.jemisonmansion.com/index.php?page=3 |title=Van de Graaff History |work=Jemison-Van de Graaff Mansion (official website) |access-date=10 July 2010 |url-status=dead |archive-url=https://web.archive.org/web/20090206131811/http://jemisonmansion.com/index.php?page=3 |archive-date=February 6, 2009 }}</ref>

His three older brothers [[Adrian Van de Graaff|Adrian, Jr.]], [[Hargrove Van de Graaff|Hargrove]], and [[William T. Van de Graaff|William]] were all [[College Football All-Southern Team|All-Southern]] [[college football]] players for the [[Alabama Crimson Tide football|Alabama Crimson Tide]]. William was known as "Bully" and was Alabama's first [[All-America]]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 founding member of The Castle Club (later became Mu chapter<ref>{{cite web|url=https://muthetatau.org/chapter-history|title=Chapter History|work=muthetatau.org|access-date=23 July 2015}}</ref> of [[Theta Tau]]).

After a year working for the [[Alabama Power Company]], Van de Graaff attended the Marie Curie lectures at the [[University of Paris|Sorbonne]] in 1925. During 1926, he earned a second B.S. at Oxford University by a [[Rhodes Scholarship]], completing his D.Phil. under [[John Sealy Townsend]] at [[Oxford University]] in 1928.<ref>{{cite news |title=February 12, 1935: Patent granted for Van de Graaff generator | newspaper=APS News |date=February 2011}}</ref>

Van de Graaff was the inventor of the [[Van de Graaff generator]], a device which produces [[high voltage]]s. During 1929, he developed his first such generator, producing 80,000 volts.<ref name="bnl">{{cite web|url=http://tvdg10.phy.bnl.gov/vandegraaff.html|title=Robert Jemison Van de Graaff was born on December 20, 1901 in Tuscaloosa, Alabama|access-date=August 23, 2004|archive-date=October 24, 2017|archive-url=https://web.archive.org/web/20171024161036/http://tvdg10.phy.bnl.gov/vandegraaff.html|url-status=dead}}</ref> By 1933, he had constructed a larger generator generating 7 million volts working together with [[John G Trump]].<ref name="bnl" />

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 [[American Physical Society]] awarded him the T. Bonner prize (1965) for the development of [[electrostatic accelerator]]s.

Van de Graaff died on January 16, 1967, in [[Boston]], [[Massachusetts]]. His wife died in 1972.

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)|Van de Graaff crater]] on the far side of the Moon is named after him.

==Van de Graaff generator==
{{Main|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 [[Museum of Science, Boston|Boston Museum of Science]]. Demonstrations during daytimes are a popular attraction. More modern Van de Graaff generators are insulated by pressurized [[dielectric gas]], usually [[freon]] or [[sulfur hexafluoride]]. 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]]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==
* {{US patent|1991236|US1,991,236}} – "''Electrostatic Generator''"
* {{US patent|2024957|US2,024,957}} – "''Electrical Transmission System''"
* [http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F2922905 US2922905]{{Dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }} — "''Apparatus For Reducing Electron Loading In Positive-Ion Accelerators''"
* {{US patent|3187208|US3,187,208}} – "''High Voltage Electromagnetic Apparatus Having An Insulating Magnetic Core''"
* {{US patent|3323069|US3,323,069}} – "''High Voltage Electromagnetic Charged-Particle Accelerator Apparatus Having An Insulating Magnetic Core''"
* [https://archive.today/20121214114319/http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtml/search-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/3239702 US3239702] — "''Multi-Disk Electromagnetic Power Machinery''"
* {{US patent|3308323|US3,308,323}} – "''Inclined field High Voltage Vacuum Tubes''"

==References==
{{Reflist}}

==External links==
*{{Commons category-inline}}
* {{MathGenealogy|id=66532}}
* {{Find a Grave|105876003}}

{{Authority control}}

<!-- Category "American Rhodes scholars" is sub-category of "Alumni of the University of Oxford", so latter not needed -->

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