Emilio Gino Segrè was born in Tivoli, outskirts of Rome, Italy in a Sephardic Jewish Family in 1905. After completing his university preparatory schooling in Rome, he enrolled as an engineering student in the University of Rome, La Sapienza. This is where he would meet Franco Rasetti, who introduced him to Enrico Fermi, who was looking for talented students to work with. This led Emilio to switch to Physics for his laurea (PhD) and he became one of the Via Panisperna boys.
With instruction from Fermi and Rasetti, Segrè received his doctorate degree in his first year itself as a physics student. Segrè would serve his compulsory military service before becoming a professor of physics, a few years later. Segrè spoke several languages, and could quote classics at length. He led a very active lifestyle, which included hikes in the alps, foraging wild mushrooms and fly-fishing in America. Segrè’s first research revolved around studying the Raman effect and the Zeeman effect. The latter opened him up to an invitation from Pieter Zeeman to work in his laboratory. Segrè received the Rockefeller foundation fellowship multiple times, and worked with Otto Stern.
Segrè started working as a professor of physics at the University of Palermo in Rome. On a visit to the US, he convinced Lawrence Berkeley Radiation Laboratory to let him take back some discarded cyclotron parts to study slow acting radiation. Study of a discarded radioactive molybdenum strip led to him discovering a new element Technetium. Segrè was frustrated by the lack of recognition to this discovery, which he considered worthy of a Nobel prize. Further, he was disappointed in the Italian government for their response. In 1938, on another visit to Lawrence Berkeley Radiation Lab, he learned that Benito Mussolini government in Italy had disallowed Jewish people from holding academic positions. This would lead Segrè to emigrate to the US with his family.
Segrè’s status as an alien would complicate his participation and collaboration on nuclear research, something that was considered high security. This meant he held the position of “Research Assistant” and was paid $300 a month. This pay was slashed to $116 when Lawrence learned that Segrè was trapped in California due to the circumstances. Due to second world war, a lot of Berkeley professors were kept busy by the war effort. Segrè supplemented his income by teaching physics as a professor at Berkeley in their absence. Later, Segrè accepted Oppenheimer’s invitation to join the Manhattan Project at Los Alamos.
While at Los Alamos, he led the group to identify U-235 and Pu-239 fission rates. His work would prove that the U-235 slow-cannon-design would still be too fast for spontaneous fission of Plutonium, and the contamination by Pu-240 isotope would result in pre-detonatiom of the bomb. This caused cancellation of the thin man atomic bomb.This would lead to a risky redesign, which proved successful in the detonation of Fat Man.
Segrè and his group were successful in measuring the gamma radiations from the Trinity test, even though intense radiation destroyed most of their apparatus. While at Los Alamos, Segrè served under the name Earl Seaman as to not raise suspicions about his alien status. In 1944 Segrè and his wife became citizens of United States. While working at Los Alamos, Segrè helped discover Astatine which would be useful in later atomic designs.
After the war, while he remained a professor at Berkeley, he would continue to pursue patent claims against the United States. The Italian scientist won the case leading to an award of $400,000 in damages. After a brief stint at the University of Illinois Urbana-Champaign, Segrè returned to Berkeley as a professor and researcher in physics. With antimatter particles already discovered for Neutron and electron, Segrè started working on verifying the existence of anti-proton. Using Lawrence Berkeley’s Bevatron particle accelerator at 6 billion eV, Segrè and his team managed to prove conclusively the existence of antiproton. Segrè and Chamberlain received the Nobel Prize in physics for this discovery.
Segrè worked as a trustee of the Fermilab at Berkeley, and supported the successful bid to separate Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory. He was an avid photographer and has taken a vast amount of photographs during his career. His photographs provide a great insight into the projects he worked on, the people he worked with and the history of his discoveries. He published a biography on Fermi and his autobiography titled “A Mind Always in Motion” which was published after his death.
Segrè died of a heart attack in 1989 at the age of 84 in Lafayette, California.
References :
- Wikipedia : Emilio Segrè
- EMILIO GINO SEGRÈ 1905–1989 A Biographical Memoir by J. DAVID JACKSON : National Academy of Sciences
- Encyclopædia Britannica: Emilio Segrè
- Atomic Heritage Foundation : Emilio Segrè
- Jewish Virtual Library : Emilio Segrè
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