Cecil Frank Powell (5.12.1903-9.08.1969) was an English physicist and a Fellow of the Royal Society (1949). He was born in Tonbridge. He graduated from the University of Cambridge (1925) and worked at the Cavendish Laboratory, where in 1927 he received his doctorate. From 1927 he was at the University of Bristol (from 1948 as professor and from 1964 as director of the laboratory).
His work was in the field of cosmic-ray physics, nuclear physics, meson physics and elementary particle physics. He improved the photographic technique for observing nuclear processes, in particular the preparation of highly sensitive thick-layer photographic emulsions. In 1947, together with C. Lattes and G. Occhialini, he discovered the charged pions (Nobel Prize, 1950). In 1949 he was the first to prove reliably the existence of kaons. He detected a new decay channel of the tau meson (kaon), which later led to the discovery of the violation of the law of conservation of parity.
He organised numerous expeditions to study cosmic rays with the help of large stratospheric balloons (in 1952 —61 he was director of the European Expedition for High-Altitude Balloon Measurements in Italy). The scientific material obtained on these expeditions became the property of many laboratories of the world.
He was active in public life; throughout 1957—62 he was head of the World Federation of Scientific Workers, was an active participant in the Pugwash movement and chairman of the Pugwash Continuing Committee (from 1967). He founded a school of physicists (E. Burhop, C. Lattes, M. Menon, D. Perkins and others). He was a member of a number of academies of sciences, in particular a foreign member of the USSR Academy of Sciences (1958). The M. V. Lomonosov Gold Medal (1967), the D. Hughes Medal (1949), the Royal Medal (1961).