{{about|the father|his son of the same name|John S. Foster Jr.}} {{Short description|Canadian physicist}} {{Infobox scientist | name = John Stuart Foster | image = <!--(filename only)--> | image_size = | alt = | caption = | birth_date = {{birth date|1890|05|30}}<ref name="frs"/> | birth_place = Clarence, Nova Scotia, Canada | death_date = {{death date and age|1964|09|09|1890|05|30}} | death_place = Berkeley, California, United States | residence = | citizenship = | nationality = | ethnicity = | fields = Physics | workplaces = McGill University | alma_mater = Yale University | doctoral_advisor = Leigh Page<br>Henry Andrews Bumstead<ref name="mathgene"/><ref name="books.nap.edu">[http://books.nap.edu/html/biomems/hbumstead.pdf] {{webarchive |url=https://web.archive.org/web/20110607053019/http://books.nap.edu/html/biomems/hbumstead.pdf |date=June 7, 2011 }}</ref> | academic_advisors = | doctoral_students = Mary Laura Chalk Rowles | notable_students = | known_for = | author_abbrev_bot = | author_abbrev_zoo = | influences = | influenced = | awards = Henry Marshall Tory Medal {{small|(1946)}}<br>Fellow of the Royal Society<ref name="frs">{{Cite journal | last1 = Bell | first1 = R. E. | doi = 10.1098/rsbm.1966.0006 | title = John Stuart Foster 1890-1964 | journal = Biographical Memoirs of Fellows of the Royal Society | volume = 12 | pages = 146–161| year = 1966 | doi-access = free }}</ref> | signature = <!--(filename only)--> | signature_alt = | footnotes = | children = John S. Foster Jr. (son) }} '''John Stuart Foster''' {{Post-nominals|country=CAN|FRS|FRSC}} (May 30, 1890 &ndash; September 9, 1964) was a Canadian physicist.<ref name="frs"/><ref name="mathgene">{{MathGenealogy|id=141208|title=John Stuart Foster}}</ref><ref>{{Cite journal | doi = 10.1063/1.3047133 | title = John S. Foster | journal = Physics Today | volume = 18 | pages = 155 | year = 1965 }}</ref>

==Biography== Born in Clarence, Nova Scotia, he completed his Ph.D. at Yale University with a dissertation on the first measurements of the Stark effect in Helium. In 1924 he gained an appointment as assistant professor at McGill University in Montreal, where he taught physics. He became associate professor in 1930.

During World War II he served as a liaison officer for the National Research Council, working at the MIT-run Radiation Laboratory on radar research and development. He developed a fast-scan radar antenna that became known as the "Foster scanner".

He returned to McGill in 1944, where he directed the construction of a 100-MeV cyclotron. This instrument was commissioned in 1949. At the time this was the second largest in the world. From 1952 until 1954 he was chairman of the physics department at McGill. He died in Berkeley, California.

==Legacy== The ''John Stuart Foster Radiation Laboratory and Cyclotron'' at McGill was named after him in 1964 and this is engraved on the side of the building now known as the M. H. Wong Building.

His son, John Stuart Foster Jr., graduated from the University of California in 1948, then became director of the Lawrence Livermore National Laboratory, director of Defense Research and Engineering for the U.S. Defense Department, and Vice President of T.R.W., Inc.

==Awards and honours== * Fellow of the Royal Society of Canada, 1929. * Awarded Levy Medal, Franklin Institute, 1930. * Henry Marshall Tory Medal, 1946. * Elected a Fellow of the Royal Society of London, 1935.<ref name="frs"/> * The crater Foster on the Moon is named after him.

==References== {{Reflist}}

==External links== * [https://web.archive.org/web/20060512063414/http://thecanadianencyclopedia.com/index.cfm?PgNm=TCE&Params=A1ARTA0002996 Canadian Encyclopedia entry] * [http://cac.mcgill.ca/campus/Buildings/Eaton_Foster_Chemical_Engineering.html Foster Radiation Laboratory and Cyclotron Building]

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{{DEFAULTSORT:Foster, John Stuart}} Category:1890 births Category:1964 deaths Category:People from Annapolis County Category:Yale Graduate School of Arts and Sciences alumni Category:Canadian physicists Category:Canadian people of British descent Category:Canadian fellows of the Royal Society Category:Fellows of the Royal Society of Canada Category:Fellows of the American Physical Society Category:Academic staff of McGill University Category:MIT Radiation Laboratory people