Career and Contributions

Career

     When Arthur Jeffrey Dempster obtained his physics degree and doctorate he pursued a career in teaching at the University of Chicago as a part time professor in 1919 and then got a full time position in 1927. As a proffesor he studied and taught about positive ion rays with Kenneth T. Bainbridge. His career was also largely revolved around mass spectrometry and the finding of stable isotopes, which allowed him to also be the chief physicist at the University of Chicago's metallurgical laboratory.  

Kenneth T. Bainbridge 

Contributions to the Field of Physics 

Mass Spectrometry 

         While teaching and working with Kenneth T. Bainbridge, Arthur Jeffrey Dempster used the knowledge gained through his years of studying to create the first modern mass spectrometer, which is a device that is used to separate and measure quantities of different charged particles. This can be used to help identify and discover stable isotopes of elements. Although, J.J Thompson created a mass spectrometer in 1912 to help prove his theory that elements have a number of different isotopes it was Arthur Jeffrey Dempster who developed a mass spectrometer that was more accurate when compared to J.J Thompson's. Dempster's mass Spectrometer was shown to be a huge contribution to his field of science as it allowed him to discover more isotopes than every other scientist except for Francis William Aston. His most famous discovery was the Uranium 235- isotope, which was crucial for the development of atomic weapons in world war two.

Arthur Jeffrey Dempster working with
a mass spectrometer. 

Uranium Isotope-235

           Arthur Jeffrey Dempster was credited with the finding of the Uranium 235- isotope. This isotope is extremely fissile, which means it can easily undergo nuclear fission. Because of this it has and is currently being used in atomic bombs. From this discovery Arthur Jeffrey Dempster made successful advances in his career as it allowed him to become the chief physicist at the University of Chicago's metallurgical laboratory, which was for the research and production of materials used in atomic weapons. 

Uranium Isotope-235

 For more information regarding how the chain reaction of uranium works within a nuclear reaction and the areas it impacts within our society today you can visit the following video.