C. F. Powell

Cecil Frank Powell ( born December 5, 1903 in Tonbridge, Kent; † August 9, 1969 in Bellano on Lake Como ) was a British physicist and Nobel laureate.

Life

Cecil Powell was born on 5 December 1903 as the son of the gunsmith Frank Powell in Tonbridge / Kent. After attending primary school, he received a scholarship to the Judd School in Tonbridge. With further scholarship he attended Sidney Sussex College, Cambridge, graduating in 1924/25 with the Natural Sciences Tripos. He received his doctorate in 1927 at the Cavendish Laboratory in Cambridge under Rutherford and Wilson and then went as a research assistant to Arthur M. Tyndall at the University of Bristol. 1936/37, took part in an expedition to the West Indies, where he operated a seismograph in study of volcanoes. In 1948 he was appointed Melville Wills Professor of Physics at Bristol.

His students included Richard Dalitz.

Powell was also politically active in the early days of the Pugwash movement.

Powell married in 1932 his assistant Isobel Therese Artner and had with her two daughters.

Work

Powell's first research in the Cavendish Laboratory dealt with condensation phenomena, which he was able to prove the existence of a supersaturation in rapidly expanding steam. This discovery had a major influence on the development and performance of steam turbines.

Bristol he developed method for accurate measurement of the mobility of positive ions and has the type of ions in the most common gases detected. After the Caribbean expedition, he worked on the construction of a Cockcroftgenerators for the acceleration of protons and deuterons, which he used along with a Wilson's cloud chamber to study the neutron-proton scattering.

From 1938 he was also involved in the cosmic rays (at that time the main source of high energy particles prior to the development of suitable accelerators) and developed methods to record the particle tracks with photographic emulsions. He later used these methods also to measure energy of neutrons by the recoil protons, in this case he was unable to establish a link between energy and track length, which soon found wide applications in experiments on nuclear and particle physics. After a further development of the photographic emulsions he succeeded with Giuseppe Occhialini, Muirhead and others 1947 Proof of the pion and the muon (then called mesons ) in cosmic rays as well as the determination of their essential characteristics. Later, however, it was announced that that had been ( first by Hideki Yukawa in 1935 theoretically proposed for the nuclear power ) Pion discovered a little earlier in 1947 by Donald H. Perkins, from Imperial College in photographic emulsions.

In this context, he was Director of the European program for high-altitude research balloon flights with in Sardinia ( 1952) and in the Po Valley (1954, 1955 and 1957).

Awards

Powell was awarded the 1950 Nobel Prize in Physics "for the development of the photographic method of studying nuclear processes and the related discovery of mesons ". In 1949 he was elected as a member ( "Fellow" ) to the Royal Society, in 1949, the Hughes Medal and 1961, the Royal Medal awarded him.

Other awards:

  • Lomonosov Gold Medal, 1967
  • Vernon Boys Prize
  • Foreign Member of the Soviet Academy of Sciences
  • Honorary doctorates from the universities of Dublin, Bordeaux and Warsaw
  • Member of the German Academy of Sciences Leopoldina, 1964

It was in 1961 at the scientific advisory board of CERN.

Writings

  • With Occhialini Nuclear physics in photographs, Clarendon Press, 1947
  • With Peter Fowler, Donald H. Perkins The study of elementary particles by the photographic method, Pergamon Press 1959
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