{{Infobox Scientist
| name              = Kenneth Bainbridge
| image             = BainbridgeLarge.jpg
| image_width       = 200 px
| caption           = 
| birth_date        = 
| birth_place       = Cooperstown, New York
| death_date        = 
| death_place       = 
| residence         = 
| citizenship       = 
| nationality       = 
| ethnicity         = 
| field             = Physics
| work_institutions = Harvard
| alma_mater        = Massachusetts Institute of Technology (B.A., S.M.)<br>Princeton University (Ph.D.)
| doctoral_advisor  = 
| doctoral_students = 
| known_for         = Nuclear mass measurements<br>Director of the Trinity test
| author_abbrev_bot = 
| author_abbrev_zoo = 
| prizes            = 
| religion          = 
| footnotes         = 
}}
'''Kenneth Tompkins Bainbridge''' (July 27 1904 &ndash; July 14 1996) was a physicist at Harvard University who did work on cyclotron research. His precise measurements of mass differences between nuclear isotopes allowed him to confirm Albert Einstein's mass-energy equivalence concept. He was the Director of the Trinity test of the Manhattan Project, which took place  July 16, 1945. Bainbridge called the Trinity explosion a "foul and awesome display" and remarked to J. Robert Oppenheimer immediately after the test, "Now we are all sons of bitches."<ref> </ref> This marked the beginning of his dedication to ending the testing of nuclear weapons and to efforts to maintain civilian control of future developments in that field. 

==Early career==

Kenneth T. Bainbridge was born on July 27, 1904 in Cooperstown, New York. He attended the Massachusetts Institute of Technology from 1922 to 1926, earning B.A. and S.M. degrees in electrical engineering. Upon completing his work at MIT, he enrolled at Princeton University. Over the previous few years, he had developed an interest in physics, and chose to pursue this new interest at Princeton. In 1929, he was awarded a Ph.D. in his new field.

Bainbridge enjoyed a series of prestigious fellowships after graduation, first awarded by the National Research Council, then the Bartol Research Foundation, and finally the Guggenheim Memorial Foundation. When his Guggenheim fellowship expired, he accepted an associate professorship at Harvard University and began working on a pair of cyclotrons. Bainbridge's work at Harvard resulted in his recruitment as leader of the MIT radiation laboratory's radar project. He worked with several notable physicists at the laboratory, including Hans Bethe and Robert Bacher. Their next assignment would call for the assembly of an atomic bomb.

In 1932, Bainbridge developed a mass spectrometer with a resolving power of 600 and a relative precision of one part in 10,000.<ref name='Audi 2006'> </ref> He used this instrument to verify the equivalence of mass and energy, E = mc<sup>2</sup>.<ref> </ref>

</ref>}}

==Manhattan Project==

In May 1943, Bainbridge joined the Project Y staff at Los Alamos. First he led E-9, which was charged with instrumentation development. After the lab reorganization of 1944, he worked under George Kistiakowsky as X-2 leader. In this position, he was in charge of "gadget" engineering and test preparations. On July 16, 1945, Bainbridge and his colleagues detonated an implosion bomb. Bainbridge was relieved that the Trinity test had been a success, relating in a 1975 Bulletin of the Atomic Scientists article, "I had a feeling of exhilaration that the 'gadget' had gone off properly followed by one of deep relief. I wouldn't have to go to the tower to see what had gone wrong."

right|thumb|Kenneth Bainbridge
'''Kenneth Bainbridge''' était un physicien nucléaire, né le 27 juillet 1904 et mort le 14 juillet 1996. Il grandit à New York où il délaissa rapidement son métier d'animateur radio pour commencer des études d'ingénierie électrique au Massachusetts Institute of Technology, où ses expériences contribueront au développement de la télévision.

Il entra ensuite au département de Physique de l'spectromètre de masse avant de rejoindre en 1934 le département de Physique de l'Université de Berkeley. 

En 1943, le cyclotron fut réquisitionné par l'armée américaine pour servir le Projet Manhattan, à Los Alamos. Il fut démonté et remonté au laboratoire des armes et ne fut jamais retourné à Harvard. 

Bainbridge fut dans le même temps recruté à Los Alamos, au laboratoire des armes nucléaires où, à la demande de Trinity. Dans l'un de ses articles paru dans le Bulletin of Atomic Scientists (1975), il décrivit précisément sa recherche d'un endroit approprié pour les tests, et le succès que fut le test du 16 juillet 1945. Sa remarque à Oppenheimer juste après l'événement,  (''Maintenant nous sommes tous des fils de pute''), marque le début de son engagement pour mettre fin aux essais d'armes nucléaires et pour garder le contrôle des futurs développements de ce domaine. 