Arthur Jeffrey Dempster

Arthur Jeffrey Dempster

Infobox_Scientist
name = Arthur Jeffrey Dempster



image_width =
caption =
birth_date = August 14, 1886
birth_place = Toronto, Canada
death_date = 1950
death_place = Stuart, Florida
residence =
citizenship =
nationality = Canadian-American
ethnicity =
field = physicist
work_institution =
alma_mater = B.S. University of Toronto
M.S. University of Toronto
Ph.D. University of Chicago
doctoral_advisor =
doctoral_students =
known_for = Developed the first modern mass spectrometer, discovered 235U (used in atomic bombs)
author_abbreviation_bot =
author_abbreviation_zoo =
prizes =
religion =
footnotes =

Arthur Jeffrey Dempster (August 14 1886 - March 11 1950) was a Canadian-American physicist best known for his work in mass spectrometry and his discovery of the uranium isotope 235U.

Biography

Dempster was born in Toronto, Canada. He received his bachelor's and master's degrees at the University of Toronto in 1909 and 1910, respectively. He travelled to study in Germany, and then left at the outset of World War I for the United States; there he received his Ph.D. in physics at the University of Chicago. Dempster then joined the physics faculty there in 1916, teaching and researching until his death in 1950, interrupted only during World War II, when he worked on the secret Manhattan Project to develop the world's first nuclear weapons. From 1943 to 1946, he was chief physicist of the University of Chicago's Metallurgical Laboratory or "Met Lab" (this lab was integrally related to the Manhattan Project: it was founded to study the materials necessary for the manufacture of atomic bombs), and in 1946 took a position as a division director at the Argonne National Laboratory. Dempster died in 1950 in Stuart, Florida.

Research

In 1918, Dempster developed the first modern mass spectrometer, a scientific apparatus allowing physicists to identify compounds by the mass of elements in a sample, and determine the isotopic composition of elements in a sample. [ cite journal|title=A New Method of Positive Ray Analysis |journal=Phys. Rev.|date=April 1918|first=A. J.|last=Dempster|coauthors=|volume=11|issue=4|pages=316–325|doi= 10.1103/PhysRev.11.316|url=http://link.aps.org/abstract/PR/v11/p316|format=PDF|accessdate=2007-11-24 ] Dempster's mass spectrometer was over 100 times more accurate than previous versions, and established the basic theory and design of mass spectrometers that is still used to this day. Dempster's research over his career centered around the mass spectrometer and its applications, leading in 1935 to his discovery of the uranium isotope 235U. This isotope's ability to cause a rapidly expanding fission nuclear chain reaction allowed the development of the atom bomb and nuclear power. Dempster was also well known as an authority on positive rays.

References

* [http://libserv.aip.org:81/ipac20/ipac.jsp?uri=full=3100001~!542~!0&profile=icos "AIP International Catalog of Sources"] . Retrieved June 17, 2005.
*Armstrong, David; Burke, Monte; "et al." Forbes.com (December 23, 2002). [http://www.forbes.com/forbes/2002/1223/124_print.html "85 Innovations 1917-1938"] .
*Encyclopædia Britannica (2005). [http://www.britannica.com/eb/article?tocId=9029915 "Dempster, Arthur Jeffrey"] . Retrieved June 17, 2005.
* [http://www.todayinsci.com/8/8_14.htm "Today in Science History"] . Retrieved June 17, 2005.

Persondata
NAME= Dempster, Arthur Jeffrey
ALTERNATIVE NAMES=
SHORT DESCRIPTION= Canadian-American physicist
DATE OF BIRTH= August 14, 1886
PLACE OF BIRTH= Toronto, Canada
DATE OF DEATH= 1950
PLACE OF DEATH= Stuart, Florida


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Arthur Jeffrey Dempster — A. J. Dempster Arthur Jeffrey Dempster (* 14. August 1886 in Toronto, Ontario; † 11. März 1950 in Stuart, Florida) war ein kanadisch US amerikanischer Physiker …   Deutsch Wikipedia

  • Dempster, Arthur Jeffrey — ▪ American physicist born Aug. 14, 1886, Toronto, Ont., Can. died March 11, 1950, Stuart, Fla., U.S.       American physicist who built the first mass spectrometer, a device used to separate and measure the quantities of different charged… …   Universalium

  • Dempster , Arthur Jeffrey — (1886–1950) Canadian–American physicist Dempster was born in Toronto, Ontario, in Canada and educated at the university there. He emigrated to America in 1914, attended the University of Chicago, obtained his PhD in 1916, and began teaching in… …   Scientists

  • Dempster — can refer to: Maple Leaf Foods Dempster Brand Bread Dempster Street, a major east west artery north of Chicago, Illinois, part of which is part of U.S. Route 14 in Illinois Dempster (CTA), stations on the Chicago Transit Authority s L system, all …   Wikipedia

  • Dempster — ist der Familienname folgender Personen: Arthur Jeffrey Dempster (1886–1950), kanadisch US amerikanischer Physiker Arthur P. Dempster, kanadisch US amerikanischer Statistiker und Universitätsprofessor Barry Dempster (* 1952), kanadischer Dichter… …   Deutsch Wikipedia

  • Arthur Dempster — may refer to:*Arthur Jeffrey Dempster (1886 1950), physicist at the University of Chicago and Manhattan Project participant *Arthur P. Dempster, mathematician and statistician at Harvard University …   Wikipedia

  • Dempster-Shafer-Theorie — Die Evidenztheorie von Dempster und Shafer ist eine mathematische Theorie aus dem Gebiet der Wahrscheinlichkeitstheorie. Sie wird benutzt, um Informationen unterschiedlicher Quellen zu einer Gesamtaussage zusammenzusetzen, wobei die… …   Deutsch Wikipedia

  • Dempster —   [ dempstə], Arthur Jeffrey, kanadischer Physiker, * Toronto 14. 8. 1886, ✝ Stuart (Fla.) 11. 3. 1950; 1927 50 Professor für Experimentalphysik an der Universität Chicago. Dempster konstruierte den ersten Massenspektrographen mit… …   Universal-Lexikon

  • Dempster — /demp steuhr, dem /, n. Arthur Jeffrey, 1886 1950, U.S. physicist. * * * …   Universalium

  • Демпстер, Артур Джеффри — В Википедии есть статьи о других людях с такой фамилией, см. Демпстер. Артур Джеффри Демпстер англ. Arthur Jeffrey Dempster …   Википедия

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”