Emilio Segrè, the Antiproton, Technetium, and Astatine

Resources with Additional Information · Patents

Emilio Segrè
Courtesy of Lawrence Berkeley
National Laboratory

Emilio Gino Segrè "was cowinner, with Owen Chamberlain of the United States, of the Nobel Prize for Physics in 1959 for the discovery of the antiproton, an antiparticle having the same mass as a proton but opposite in electrical charge.

Segrè initially began studies in engineering at the University of Rome in 1922 but later studied under Enrico Fermi and received his doctorate in physics in 1928. In 1932 Segrè was appointed assistant professor of physics at the University of Rome, and two years later he participated in neutron experiments directed by Fermi … . In 1935 they discovered slow neutrons, which have properties important to the operation of nuclear reactors.

Segrè left Rome in 1936 to become director of the physics laboratory at the University of Palermo [in Italy]. One year later he discovered technetium, the first man-made element not found in nature. … [In 1938 he became] a research associate at the University of California, Berkeley. … [H]e and his associates discovered the element astatine in 1940, and later, with another group, he discovered the isotope plutonium-239, which he found to be fissionable, much like uranium-235. Plutonium-239 was used in the first atomic bomb and in the bomb dropped on Nagasaki.

From 1943 to 1946 Segrè was a group leader at the Los Alamos Scientific Laboratory, Los Alamos, N.M. He was naturalized as a U.S. citizen in 1944 and was professor of physics at Berkeley (1946-72). In 1955, using the new bevatron particle accelerator, Segrè and Chamberlain produced and identified antiprotons and thus set the stage for the discovery of many additional antiparticles."

– Excerpts from Emilio Segrè, Pioneers of Nuclear Medicine

Resources with Additional Information

Additional information about Emilio Segrè, the antiproton, Technetium, and Astatine is available in electronic documents and on the Web.


Formation of the 50-Year Element 94 from Deuteron Bombardment of U238, DOE Technical Report, 1942

Spontaneous Fission, DOE Technical Report, November 1950

Observation of Antiprotons, DOE Technical Report, October 1955

Antiprotons, DOE Technical Report, November 1955

The Antiproton-Nucleon Annihilation Process (Antiproton Collaboration Experiment), DOE Technical Report, September 1956

Experiments on Antiprotons: Antiproton-Nucleon Cross Sections, DOE Technical Report, July 1957


Additional Web Pages:

Observation of Antiprotons

The Golden Anniversary of the Antiproton, science@berkeley lab, October 27, 2005
Emilio Segrè and Spontaneous Fission

Dr. Segrè Biography submitted to the Nobel Committee

A Mind Always in Motion, Autobiography of Emilio Segrè

Emilio Gino Segrè Biographical Memoir (PDF) (html), National Academy of Sciences

Emilio Segrè, IEEE

Emilio Segrè, American Institute of Physics (AIP)


Named After Segrè:


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