DZHELEPOV 94 



Beginning in 1945, Dzhelepov has worked at the Radium Institute 

 of the U.S.S.R. Academy of Sciences. He was elected, in 1953, 

 a Corresponding Member of the U.S.S.R. Academy of Sciences. 

 Dzhelepov' s field is nuclear physics. In 1932-41 he studied 

 the energy spectra of electrons emitted by artificially created 

 radioactive elements. In 1938 he designed a gamma spectrome- 

 ter, based on pair formation. In 1948, together with Orbeli, he 

 developed a gamma spectrometer, based on the measurement 

 of recoil electron energy knocked out by gamma rays in the 

 direction of its initial movement. In 1954 this method was im- 

 proved and a new device was built. Dzhelepov and associates 

 studied beta and gamma spectra and spectra of conversion elec- 

 trons of more than thirty radioactive isotopes. Together with 

 N. A. Vlasov, he studied the angular distribution of quanta 

 formed during positron annihilation, which permitted the evalu- 

 ation of the velocities of positrons at which they are annihilated 

 in solid bodies. Dzhelepov analysed data on beta disintegration, 

 on mirror nuclei, and on isotopic spin. 

 Bibliography: 



and L. N. Syryanova . Influence of the Electric Field of an 

 Atom on Beta Disintegration. Moscow -Leningrad: 1956. 

 and Q. E. Kraft. Positrons in inner conversion of radio- 

 active isotopes Sb 124. Izvest. Akad. Nauk S.S.S.R., Ser. Fiz., 

 1956, 20, #3. 



and S. A. Shestopalova . Magnetic gamma spectrometer with 

 improved focussing-electron. Izvest. Akad. Nauk, Ser. Fiz., 

 1956, _20, #3. 



and I. A. Yaritsyna . The study of hard gamma rays with low 

 intensity with the aid of the photoneutron effect. Izvest. 

 Akad. Nauk, Ser. Fiz., 1956, 20, #3. 



and others. Spectrum of gamma rays S\^^'^^. Izvest. Akad. 

 Nauk, Ser. Fiz., 1956, 20, #8. 



and S. A. Shestopalova. About — *- transformation into 

 RaC. Izvest. Akad. Nauk, Ser. Fiz., 1956, 20, #8. 

 and others . A new method of improving the focusing proper- 

 ties of a lens spectrometer. Izvest. Akad. Nauk, Ser. Fiz., 

 1956, 20, #8. 



and L. K. Peker. On equally solved beta -transformations. 

 Doklady Akad. Nauk, 1956, 106, #4. 



and I. M. Vokhanskii, A. I. Medvedev, I. F. Uchevatkin. The 

 nature of Erl67 at a level of 531.8 kev. Doklady Akad. Nauk 

 S.S.S.R. 146, #2, 789-92 (1962). 



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