Joliot (Joliot), Frederic( French physicist)
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Biography Joliot (Joliot), Frederic
March 19, 1900, Mr.. - August 14, 1958
French physicist Frederic Joliot Jean was born in Paris. He was the youngest of six children in the family of a prosperous businessman Henri Joliot and Emilia (Roderer) Joliot, which came from a prosperous Protestant family from Alsace. In 1910,. the boy was learning the Lyceum Lakanal, provincial boarding school, but seven years after his father's death he returned to Paris and became a student at Ecole townhouse syuperer Lavoisier. Having decided to devote himself to scientific careers, F. in 1920. enrolled in the Higher School of Physics and Applied Chemistry in Paris and three years later he graduated its best in the group.
Resulting F. diploma engineer said that in the formation of a future scientist prevailed practical application of chemistry and physics. However, the interests of M. lay rather in the field of basic research that is largely due to the influence of one of his teachers at the Higher School of Physics and Applied Chemistry - French physicist Paul Langevin. After compulsory military service, J., Langevin discussed with their plans for the future, got advice to try to take a position as an assistant to Marie Curie at the Radium Institute of Paris University.
M. the advice and in early 1925. assumed his new duties at the Institute, where, working taxidermist, continued to study chemistry and physics. The following year he married Irene Curie, daughter of Marie and Pierre Curie, who also worked at this institute. Since her marriage last name changed to Irene Joliot-Curie. In spouses born son and daughter, both of whom are scientists. A J., receiving a Licentiate (equivalent to M.Sc.), continued its work in 1930. was awarded a doctorate for a study of electrochemical properties of the radioactive element polonium.
Attempts to find an academic position were unsuccessful, and M. quite been decided to return to the work of chemist practice on industrial production, but Perrin has helped him win a government scholarship that enabled M. stay at the institute and to continue research related to radiation exposure. In 1930. German physicist Walther Bothe discovered, . some light elements, . in particular, beryllium and boron, . emit a strong penetrating radiation by bombarding them moving with high speed helium nuclei (later it was named by irradiation of alpha-radiation), . formed by the decay of radioactive polonium.,
. Knowledge engineering has helped M
. construct a sensitive detector with the condensing chamber, in order to capture this radiation, and prepare a sample with an unusually high concentration of polonium. With this apparatus wife Joliot-Curie (as they called themselves), . began their cooperation in 1931, . found, . that a thin plate of hydrogenous material, . located between irradiated beryllium or boron, and a detector, . increases the initial radiation almost doubled.,
. Additional experiments showed them that this additional radiation is composed of atoms of hydrogen, which is caused by ionizing radiation released by acquiring an extremely high speed
. Although neither of these two researchers did not understand the essence of the process, nevertheless held their precise measurements led to the fact that in 1932. James Chadwick discovered the neutron - a neutral particle that is included in the atomic nucleus.
Byproducts in the bombardment of boron or aluminum with alpha particles are also positrons (positively charged electrons), which in the same 1932. were found American physicist Carl D. Anderson. Spouses Joliot-Curie studied these particles with the end of 1932. - Throughout 1933, and in early 1934. started a new experiment. Closing the opening of the condensing chamber a thin plate of aluminum foil, they irradiated samples of boron and aluminum alpha radiation. As they expected, the positrons emitted in fact, but to their surprise, positron emission lasted for several minutes after it removed the polonium source.
. Thus, Joliot-Curie discovered that some of the samples subjected to analysis of aluminum and boron into new chemical elements
. Moreover, these new elements were radioactive: aluminum, absorbing two protons and two neutrons, alpha particles, turned into a radioactive phosphorus, and boron - a radioactive isotope of nitrogen. Since these unstable, radioactive elements were not like any of the naturally produced radioactive elements, it was clear that they were created artificially. Subsequently, the wife Joliot-Curie synthesized a large number of new radioactive elements.
In 1935. Frederick M. and Irene Joliot-Curie were jointly awarded the Nobel Prize in Chemistry 'made for the synthesis of new radioactive elements ". KV. Palmayer presenting them on behalf of the Royal Swedish Academy of Sciences, said: 'Thanks to your discovery was first made possible the artificial transformation of one element to another, until then unknown. The results of your research are of paramount purely scientific value '. 'But in addition, - continued Palmayer - physiologists, doctors and all the suffering humanity hope to gain through your discoveries of precious drugs'.
In his Nobel lecture M. noted that the use of artificial radioactive elements as a tracer 'simplify the problem of finding and removing the various elements that exist in living organisms'. From the accumulated information, he said, 'we can conclude that we should not assume, though a few hundred atoms, forming our planet were created all at once and will live forever'. Furthermore, added J., 'we have reason to believe that the scientists ... able to carry out conversion of the explosive nature, these chemical chain reactions', which released a huge amount of useful energy. 'However, if the expansion will extend to all elements of our planet - a scientist warned - the consequences of unleashing such a disaster can only cause alarm'.
In 1937, Mr.. J., continuing to work at the Radium Institute, at the same time and took the post of professor at the College de France in Paris. Here he created the Research Center for Nuclear Physics and Chemistry, and founded a new laboratory, where the departments of physics, chemistry and biology to work in close collaboration. In addition, the scientist supervised the construction of one of the first cyclotrons in France, which in research as a source of alpha particles were used radioactive elements.
. In 1939, following the discovery by German chemist Otto Hahn possibility fission (splitting) of uranium atoms, M
. found a direct physical evidence that such a division is explosive. Recognizing that a huge amount of energy released in the process of splitting the atom, can be used as an energy source, he purchased from Norway almost all of the then-available amount of heavy water. However, the outbreak at this time of the Second World War and the occupation of France, Germanic armies forced him to suspend investigations. At considerable personal risk, F. managed to smuggle in its possession the heavy water to England, where it was used by British scientists in their efforts to develop atomic weapons.
Staying in Paris during the occupation, F. retained the positions at the Radium Institute and the College de France. As an active member of the Resistance movement, he used the opportunity of his laboratory for making explosives and radio equipment for the Resistance fighters until 1944, when he himself went into hiding.
. After the liberation of Paris M
. was appointed director of the National Center for Scientific Research, it was responsible for restoring the country's scientific potential. In October 1945,. ZH. convinced President Charles de Gaulle to create the Atomic Energy Commission of France. Three years later he led the launch of the first French nuclear reactor. Despite the fact that the credibility of M. as a scholar and administrator was extremely high, its relationship with the Communist Party, which he joined in 1942, was resented, and in 1950, Mr.. He was released from his post as head of the Atomic Energy Commission.
Now M. devoted much of his time to research in the laboratory and teaching. Being an active politician, he was also president of the World Peace Council. The death of Irene Joliot-Curie in 1956. was for M. heavy blow. Having her successor as director of the Institute of Radium, and replacing it with the teaching at the Sorbonne, he has assumed control over the construction of a new institute at Orsay, south of Paris. However, his organism has been weakened because of the transferred two years earlier, viral hepatitis, and 14 August 1958. ZH. died in Paris after surgery related to internal bleeding.
M. described as a sensitive man, kind and patient. He loved to play the piano, painting landscapes and read. In his later years devoted much time with political issues. In 1940. Columbia University scientist awarded gold medal Barnard for outstanding scientific achievements,. ZH. was a member of the French Academy of Sciences and the Medical Academy of France, as well as a foreign member of many scientific societies.