Powell Cecil( English physicist, Nobel Prize in Physics, 1950)
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Biography Powell Cecil
December 5, 1903, Mr.. - August 9, 1969
English physicist Cecil Frank Powell was born in Tonbridge (Kent), the son of a schoolteacher's daughter, Caroline Elizabeth (nee Bisakr) Powell and gunsmith Frank Powell. Litigation over the accidental discharge devastated father and the family began to experience financial difficulties. P. studied at the local primary school until until the age of eleven did not receive a scholarship that enabled him to study at the Judd School in Tonbridge, where one teacher was able to awaken his interest in physics. Great achiever in all subjects, P. has scholarships that allowed him to enter the Sydney-Sussex College in Cambridge, which he graduated in 1925. summa cum laude in physics.
Although he was offered a teacher, P. chose to stay in Cambridge, where he enrolled in graduate school to CH.T.R. Wilson and Ernest Rutherford. In his first independent study of P. tried to improve the camera, invented by Wilson in 1911, in the hope that it will register the nuclear particles with higher energies. Attempts were unsuccessful, but in the course of his experiments, he became a deeper understanding of the processes of condensation of gases in the cloud chamber. For his work, P. in 1927. receives doctorate.
The following year, P. becoming an assistant researcher at п-.п°. Tindala University of Bristol. In 1931, Mr.. he begins to lecture on physics, followed by appointment to the post of senior lecturer in physics (1946), Professor of Physics (1948) and director of the university physics laboratory (1964). From 1964 to 1967. He also holds the post of Vice-Chancellor of the University.
In Bristol P. began his studies with measurements of ion motion in gases. Tindal, believing that the future of the university depends on the research on nuclear physics, applied to P. request to lead the construction of the accelerator - a project which P. worked until 1939. In 1936, Mr.. it a few months prorogued, . to go as a seismologist with the British scientific expedition to the island of Montserrat in the West Indies, . because the government feared possible catastrophic volcanic eruption (fortunately, . not held).,
. Shortly after the completion of construction of the accelerator P
. interested in the potential uses of photographic plates to detect tracks (traces) of electrically charged particles. Although this method was used in the past, scientists have abandoned it, because they believed that the photographic emulsion does not allow to obtain accurate and reliable results. Most of the subsequent studies was associated with the use of a cloud chamber.
. AP, . however, . was convinced, . that can serve as a photo-sensitive tool for precise measurements of particle physics, . because it allows you to record any track of the charged particle, . passing through the emulsion, . while in the cloud chamber tracks can be observed only for very short periods of time,
. In the late 30-ies. P. persuaded specialists on photos to develop new, more sensitive emulsion specifically designed for physics research, and bought high-quality microscopes for studying German plates. But, despite all efforts, the results of initial studies P. been disappointing.
After the Second World War (1939) P. and his colleagues took part in the British Atomic Energy Project, doing measurements of the neutron energy. In the postwar period, the resumption of work on the detection of particles, P. persuaded the company to produce photographic 'Ilford' and 'Kodak' to focus on creating special emulsions and new methods of expression for the fixation of the film tracks of nuclear particles. In 1946, Mr.. Ilfordskaya laboratory improved emulsion, and it is possible to obtain a more distinct image particle tracks and measure with greater reliability. With the new emulsion P. took up the study of cosmic rays in the Pyrenees: choice of a considerable height above sea level (about 3000 m) due to the fact that the Earth's atmosphere prevents many particles, cosmic rays come closer to Earth.
In 1947, Mr.. with colleagues, it opens in a new cosmic ray charged particles - pi-meson, or pion. Pion mass of 273 times larger than the electron mass, and approximately one-seventh of the mass of the proton. Peony - and short-lived particle decays into a muon (a particle, akin to the electron) and neutrino (a particle with no mass and electric charge). Peony mainly responsible for the interaction between protons and neutrons and the nucleus does not disintegrate. Opening of the pion was predicted in 1935. Japanese physicist Hideki Yukawa and subsequently led to the discovery of many subatomic particles. P. and his colleagues also discovered the K-mesons, which are heavier than pi-mesons, have even less time of life and are also involved in the forces that keep the particles from the decay of the atomic nucleus.
Expanding the search for cosmic particles, P. runs photographic plates in the higher layers of the atmosphere, first with a balloon and then with rockets. In 1952, Mr.. He carries a satellite mission in the Mediterranean basin, where favorable weather conditions allow for longer flights probe. At the start of probes, their return and analysis of film to detect tracks of new particles with P. collaborating scientists from many countries in Europe.
P. was awarded the Nobel Prize in Physics 1950 g. 'for the development of a photographic method of studying nuclear processes and the discovery of mesons, carried out using this method'. When presenting the winner of A. Lindh, a member of the Royal Swedish Academy of Sciences, said: 'P. deserves special thanks, because he has convincingly demonstrated that the opening of the fundamental values can be committed by the simplest of equipment (in this case, special nuclear emulsion, developed under the general direction) and microscopes'.
. After receiving the Nobel Prize P
. continues to study cosmic rays, extending the scope of international projects aimed to examine the range of phenomena. It also conducts research related to the use of accelerators. Deeply conscious of the social responsibility of scientists, it has increasingly collaborating in research institutions dealing with nuclear non-proliferation. When he was president of the Association of Scientific Workers (1952 ... 1954) he demanded that the British Government has taken steps to ban nuclear weapons. In 1955, Mr.. P. persuaded eight other distinguished scientists, including Albert Einstein, Bertrand Russell to sign the appeal, in which the peoples of the world have warned about the horrors of nuclear war and called for the convening of the Conference on Disarmament. P. was also a member of the Pugwash movement and participated in the plenary sessions of the first Pugwash Conference in 1957
In 1932, Mr.. P. married Isabel Teresa Artner from Hamburg, which introduced him to Max Delbruck. In the couple's two daughters. P. died suddenly while on vacation, which he spent in Milan (Italy).
P. has been awarded many honorary titles and medals, including medals for Hugh (1949) and Royal Medals (1961) Royal Society of London and the gold medal Lomonosov USSR (1967). He was a member of the Royal Society of London and a foreign member of numerous scientific societies around the world. In 1961 ... 1963. He was chairman of the Committee on Science Policy of CERN (European Organization for Nuclear Research), Universities of Dublin, Bordeaux and Warsaw assigned him honorary degrees.