- Egon Bretscher
Born near
Zurich , Switzerland in 1901 and educated at the ETH there, Bretscher gained a PhD degree in organic chemistry at Edinburgh in 1926. He returned to Zurich as privat docent toPeter Debye , later moving in 1936 to work in Rutherford’s laboratory at the Cavendish in Cambridge as a Rockefeller Scholar. Here he switched to research innuclear physics , proposing (withNorman Feather ) in 1940 that the 239 isotope of element 94 could be produced from the common isotope ofuranium-238 byneutron capture and that, likeU-235 , this should be able to sustain anuclear chain reaction . A similar conclusion was independently arrived at byEdwin McMillan andPhilip Abelson atBerkeley Radiation Laboratory . In addition, he devised theoretical chemical procedures for purifying this unknown element away from the parent uranium; this element was namedPlutonium byNicholas Kemmer . In 1944 he became a part of the British Mission to theManhattan Project inLos Alamos, New Mexico led byJames Chadwick , where he made the first measurements on the energy released in fusion processes.In 1947 he was invited by
John Cockcroft to head the Chemistry Division at the newly establishedAtomic Energy Research Establishment atHarwell, Oxfordshire , England and in 1948 succeededOtto Frisch as head of the Nuclear Physics Division there. Amongst his colleagues wereBruno Pontecorvo (in the Nuclear Physics Division) andKlaus Fuchs (head of the Theoretical Physics Division). He was awarded a CBE on retirement from Harwell and died in Switzerland in 1973.He used to joke that his main contribution to physics occurred in the 1920s, when he was climbing with another student
Felix Bloch in theSwiss Alps . Bloch slipped over an icy edge but was saved, as he fell, by the rope joining him to Bretscher. The latter's swift action in driving his ice axe into the ice prevented their combined demise. Bloch later won theNobel Prize for physics for his discovery ofnuclear magnetic resonance .
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