Kurchatov, Igor

KHARITON, YULI (1904-1996). Russian physicist. Khariton was among the founders of the Soviet nuclear weapon program. His influence was greatest through his position as director of Arzamas-16, the secret nuclear weapon complex that he established in 1946. In the 1920s, Khariton studied under the famed British physicist Ernest Rutherford. See also KURCHATOV, IGOR VASILIEVICH SAKHAROV, ANDREI DMITRIYEVICH SEMIPALATINSK. 

New data, reportedly issued by Soviet scientists, have reduced the half-life of the isotope they worked with from 0.3 to 0.15 s. The Dubna scientists suggest the name kurchatauium and symbol Ku for element 104, in honor of Igor Vasilevich Kurchatov (1903-1960), former Head of Soviet Nuclear Research. 

Element 104, the first transactinide element, is expected to have chemical properties similar to those of hafnium. It would, for example, form a relatively volatile compound with chlorine (a tetrachloride). The Soviet scientists have performed experiments aimed at chemical identification, and have attempted to show that the 0.3-s activity is more volatile than that of the relatively nonvolatile actinide trichlorides. This experiment does not fulfill the test of chemically separating the new element from all others, but it provides important evidence for evaluation. New data, reportedly issued by Soviet scientists, have reduced the half-hfe of the isotope they worked with from 0.3 to 0.15 s. The Dubna scientists suggest the name kurchatovium and symbol Ku for Element 104, in honor of Igor Vasilevich Kurchatov (1903—1960), late Head of Soviet Nuclear Research. The Dubna Group also has proposed the name for Element 104. In 1969, Ghiorso, Nurmia, Harris, K. A. Y. Eskola, and P. L. Eskolaof the University of California... 

Nuclear research in the Soviet Union during this period was limited to skillful laboratory work. Two associates of Soviet physicist Igor Kurchatov reported to the Physical Review in June 1940 that they had observed rare spontaneous fissioning in uranium. The complete lack of any American response to the publication of the discovery, writes the American physicist Herbert F. York, was one of the factors which convinced the Russians that there must be a big secret project under way in the United States. It was not yet big, but by then it had begun to be secret. 

Work toward an atomic bomb had begun in the USSR in 1939. A thirty-six-year-old nuclear physicist, Igor Kurchatov, the head of a major labora-... 

In 1964 a Soviet team led by G. N. Flerov at the Joint Institute for Nuclear Research at Dubna announced the discovery of element 104 after bombarding plutonium-242 atoms with neon-22 ions. They proposed that the element name should be kurcha-tovium Ku to honor Igor Kurchatov, a Soviet pioneer in nuclear physics. At Berkeley... 

SEMIPALATINSK. Now located in Kazakhstan, Semipalatinsk was the principal nuclear weapon test site of the Union of Soviet Socialist Republics (USSR). It was established in accordance with a 1947 decision by the Soviet Communist Party s Central Committee and the Council of Ministers. The USSR detonated its first nuclear weapon there on 29 August 1949 under the scientific direction of Igor V. Kurchatov. It was also the site where the USSR detonated its first thermonuclear weapon (12 August 1953) and its first hydrogen bomb (22 November 1955). A total of 467 nuclear weapons were detonated at Semipalatinsk firom 1949 to 1990. The test facility was shut down in 1991. The site is today occupied by the National Nuclear Center of the Republic of Kazakhstan. The region has experienced serious environmental and human health damage as a result of the nuclear weapon tests. See also JOE. 

---