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National Museum of Nuclear Science & History

Lew Kowarski was a Russian-born French physicist. He worked as part of the team that discovered that neutrons were emitted in the fission of uranium-235 in the 1930s, setting the groundwork for the use of nuclear chain reactions in the design of the atomic bomb.

When World War II broke out in Europe in 1939, Kowarski fled France and moved to England, where he continued research at the Cavendish Laboratory in Cambridge for the MAUD Committee, part of the wartime Tube Alloys project. Just before the German invasion, Kowarski’s records and papers were smuggled out of France. Included in this operation were 26 drums of heavy water, the world’s entire stock at the time. 

After the Second World War, Kowarski went on to supervise the first French nuclear reactors. He became a staff member of the European Organization for Nuclear Research, or CERN, in 1953.

Lew Kowarski's Timeline
1907 Feb 10th Born in Saint Petersburg, Russia.
1928 Received Chemical Engineering degree from the University of Lyon.
1935 Received Sc.B and Ph.D. in Physics from the University of Paris.
19341936 Became personal secretary to Frédéric Joliot-Curie at the University of Paris.
1945 Supervised the construction of Canada's first nuclear reactor (ZEEP) at the Chalk River Laboratories.
19481952 Supervised the construction of the first two French nuclear reactors.
1953 Appointed staff member of the European Organization for Nuclear Research (CERN).
1979 Jul 30th Died in Geneva, Switzerland.

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