The Nobel Tradition at Berkeley
Emilio Segrč
Physics, 1959
By Russell Schoch
1984
Emilio Gino Segrč, the son of a paper mill owner, was born February 1,
1905 and raised in Tivoli, Italy. A move to Rome and entrance at the
University of Rome brought Segrč into contact with Enrico Fermi, one of the
greatest physicists in history. Segrč became the first person to earn a Ph.D.
under Fermi's sponsorship (in 1928) and worked with Fermi in applying the
newly discovered quantum mechanics to atomic and molecular phenomena. When
Fermi became interested in nuclear physics and carried out his epoch-making
research on the production of artificial radioactivity by neutron absorption,
Segrč was by his side. He was a co-author, with Fermi and others, of a series
of papers published in 1934 and following years which are among the most
important of our time, initiating (on the basis of discoveries by others) the
field of neutron physics and laying the groundwork for the later development
of atomic energy.
In 1935, Segrč was named professor of physics and chairman of the
department at the University of Palermo, on the island of Sicily, where he
continued his interest in nuclear physics. While on an extended visit to the
Berkeley campus in 1936, he noted that certain parts of the internal structure
of the cyclotron received a very strong deuteron bombardment when the machine
was operating; he asked if he could have these parts when the cyclotron was
rebuilt. They were sent to him at Palermo, and in one of them he and C.
Perrier identified a new element, the first man-made element (Segrč named it
"technetium," from the Greek word for "artificial").
Two years after his fruitful visit to Berkeley, troubles with the Fascist
regime forced Segrč to flee the land of his birth. He joined the staff of the
Lawrence Radiation Laboratory, where he entered a period of great activity.
When fission was discovered, followed by the discovery of neptunium and
plutonium, he set out to answer a key question for the future of atomic
energy; is plutonium fissionable by slow neutrons? It was, and when the Los
Alamos Laboratory of the Manhattan Project was established, Segrč went there
as a leading member of the scientific staff, carrying out important studies of
the fission process.
After the war, Segrč (by now a United States citizen) returned to Berkeley
as a professor in the Department of Physics. Perhaps his crowning achievement
was the discovery, with Owen Chamberlain, of the anti-proton, in 1955. The
Chamberlain-Segrč team detected the anti-protons by designing a maze through
which only anti-protons could pass. "We had to sort them out and weigh
them within much less than one-Millionth of a second," Segrč later
recalled. "If we had wanted to have them for a longer time, we would have
had to dig a tunnel in the Berkeley hills to run after them."
While near the goal in the fall of 1955, Segrč and Chamberlain kept the
World Series scores and the number of anti-protons they found on the same blackboard.
Four years later, the World Series would be forgotten, but the other marks
were remembered by the committee that awards the Nobel Prize. In 1959, Segrč
and Chamberlain shared the Nobel Prize in Physics for their discovery of the
anti-proton. Professor Segrč retired from the Berkeley campus in 1972.
----------
Schoch, Russell. "Emilio Segrč:
Physics, 1959." The Nobel Tradition in Berkeley: University
of California, Berkeley. UC Berkeley Development
Office: UC Press, 1984, p. 18.
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