Owen Chamberlain
1920–2006, San Francisco, California, Berkeley, California
American physicist and key member of the team that discovered the antiproton at the Bevatron, winning the 1959 Nobel Prize in Physics.
Born in San Francisco, Chamberlain studied at Dartmouth and began graduate work at Berkeley under Ernest Lawrence. His studies were interrupted by the war: he joined the Manhattan Project at Los Alamos in 1943, working on bomb core assembly.
He completed his doctorate at Chicago in 1949 under Enrico Fermi and returned to Berkeley, where he joined Emilio Segrè's team that discovered the antiproton in 1955 — and later the same group observed the production of antineutrons. He was also a noted peace advocate, signing petitions against the Vietnam War.
Nobel-winning work
Chamberlain was a key member of the Bevatron team — Segrè, Chamberlain, Clyde Wiegand, and Thomas Ypsilantis — that in 1955 searched for antiprotons produced when 6 GeV protons struck a copper target. He played a central role in designing the velocity-selecting detector system: two scintillation counters measuring time of flight combined with a differential Cherenkov detector sensitive only to particles in the expected antiproton velocity range.
The arrangement determined each particle's velocity and mass simultaneously, proving the negative particles passing through had exactly the proton mass — not stray negative kaons or pions. The discovery of the antiproton, published in Physical Review in 1955, confirmed the existence of antibaryons predicted by Dirac's theory.
Workplaces: University of California, Berkeley, Los Alamos National Laboratory
United States