Bruno Pontecorvo

Bruno Pontecorvo (right) in a discussion.

Bruno Pontecorvo (born August 22, 1913 in Pisa , † September 24, 1993 in Dubna , Russia ) was an Italian physicist . He made important research in the field of neutrinos .

Life

Pontecorvo, who came from a wealthy Jewish family in Pisa, was the brother of the geneticist Guido Pontecorvo (1907–1999) and the director Gillo Pontecorvo . He studied in Rome and in the 1930s he belonged to the group of physicists around Enrico Fermi , where he was one of the youngest members and became a close collaborator and friend of Fermi. He was involved in Fermi's experiments with slow neutrons . From 1936 he worked in Paris in the laboratory of Irène Joliot-Curie and Frédéric Joliot-Curie on nuclear physics. In Paris he also turned to socialism. When the German occupation threatened, he fled France via Spain to the USA in 1940. There he developed a borehole investigation method with neutron radiation for an oil company in Tulsa .

Because of his socialist convictions he was not allowed to participate in the Manhattan Project , but from 1943 he was in the Montreal Laboratory in Canada , where he worked on the design of nuclear reactors, on cosmic radiation, the decay of the muon and neutrinos. In 1948 he became a British citizen and at the invitation of John Cockcroft went to AERE in Harwell, where he was in the nuclear physics department under Egon Bretscher (1901–1973). In 1950 he became professor of physics at the University of Liverpool .

On August 31, 1950, without telling friends or acquaintances, he suddenly disappeared from a vacation stay in Rome with his wife and three children and went to the Soviet Union via Stockholm and Finland . A similar case of espionage to that of Klaus Fuchs was suspected in the West , but Pontecorvo only had very limited access to secret information in Western atomic bomb projects. Pontecorvo did not report back to Soviet Pravda until 1955 and asked western scientists to research only into a civilian use of atomic energy . He spent the rest of his life with his family in Russia , where he enjoyed great privileges and died in 1993. He only left the Soviet Union again in 1978 on a visit to Italy. Most recently he suffered from Parkinson's disease . At his own request, half of his ashes are in Rome in the Protestant cemetery and half are buried in Dubna.

Pontecorvo was in the Soviet Union at the United Institute for Nuclear Research (JINR) in Dubna .

In 1953 he received the Stalin Prize , in 1958 he became a member of the Soviet Academy of Sciences and he was twice awarded the Order of Lenin . In 1963 he received the Lenin Prize .

Pontecorvo was one of the first to consider the possibility of observing neutrinos and neutrino oscillations. In 1946 he proposed a method of observing antineutrinos from reactors, a method by which Frederick Reines and Clyde Cowan discovered the neutrino in 1956. Reines received the Nobel Prize for this in 1995. In 1959 he proposed a method of observing the muon neutrino, which Jack Steinberger , Melvin Schwartz and Leon Max Lederman succeeded in 1962 , who received the Nobel Prize for this in 1988. In 1957 he considered the idea of neutrino oscillations , which became one of his main areas of interest. They were also confirmed experimentally in the 1980s and 1990s. In 1969, together with Vladimir Gribov , he proposed the possibility of violating the number of leptons using a Majorana mass term of neutrinos, and they applied this to the problem of solar neutrinos.

The Bruno Pontecorvo Prize for Elementary Particle Physics has been awarded by the JINR since 1995.

literature

• Miriam Mafai Il lungo freddo: Storia di Bruno Pontecorvo, lo scienziato che scelse l'URSS , Milan 1992
• Stefano Salvia: “From Russia with Love”: The Pontecorvo Affair, in: Christian Forstner, Dieter Hoffmann (ed.), Physik im Kalten Krieg, Springer 2013, pp. 149–161
• Simone Turchetti: The Pontecorvo Affair. The unusual career of the Italian nuclear physicist , Physik Journal, 2013, No. 10, p. 43
• Simone Turchetti: The Pontecorvo Affair , University of Chicago Press 2012

Web links

• Literature by and about Bruno Pontecorvo in the catalog of the German National Library
• Biography at JINR

Individual evidence

1. ^ Bruno Pontecorvo in the Encyclopaedia Britannica