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The total energy of the γ-radiation emitted from the active deposit of actinium

  • E. Kara-Michailova (a1)


The disintegrations by which Ac B passes into the inactive AcPb are accompanied by a γ-radiation very weak compared with the intense γ-emission in the case of Ra or Th-active deposit. The analysis of the secondary β-ray spectrum of actinium-active deposit has revealed the existence of at least five γ-rays (1) (see Table I), of which the ray with energy 0·349 × 106 e.V. definitely belongs to the disintegration Ac C—C″ and is associated with the fine-structure of α-particles of Ac C. According to the measurements of Surugue the two rays of 0·4038 × 106 and 0·4257 × 106 e.V. energy are to be attributed to the disintegration AcB—C, whereas the origin of the 0·829 × 106 e.V. ray is less definite. The fit with experiments is best if this ray is assumed to be emitted from Ac B—C; but it may also (within experimental error) be attributed to the disintegration Ac C″—Pb. Experiments on the absorption coefficient of the γ-radiation of RaAc and its disintegration products prove that the 0·829 × 106 e.V. ray is the hardest γ-ray emitted by the active deposit of actinium(2). The value for the absorption coefficient between 4·6 and 10·6 cm. of lead was found to be μ/ρ = 0·76, in good agreement with the value found in previous experiments at smaller absorptions in aluminium (3). There is, on the whole, excellent agreement concerning the energies of the γ-components as measured according to different methods by different observers.



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(1)Subugue, J.Journ. de Phys. (7) 7 (1936), 337.
(2)Curie, M. and Savel, P.Journ. de Phys. (7) 4 (1933), 457.
(3)Rutherford, E. and Richardson, H.Phil. Mag. 26 (1913), 937.
(4)Li, K. T.Proc. Roy. Soc. A, 158 (1937), 571.
(5)Hulme, H. R., Mott, N. F., Oppenheimer, F. and Taylor, H. M.Proc. Roy. Soc. A, 155 (1936), 315.
(6)Ellis, C. D. and Aston, G. H.Proc. Roy. Soc. A, 129 (1930), 180.
Skobeltzyn, D.Zeitschr. f. Phys. 58 (1929), 595.
Alichanow, A. I. and Spiwak, P. E.Phys. Zeitschr. d. Sowjet-Union, 11 (1937), 351 and 354.
(7)Tarrant, G. T. P.Proc. Cambridge Phil. Soc. 28 (1932), 475.
(8)Sargent, B. W.Proc. Cambridge Phil. Soc. 25 (1929), 514.
(9)Zlotowski, I.Journ. de Phys. (7), 6 (1935), 242.
(10)Gray, L. H.Proc. Roy. Soc. A, 159 (1937), 263.
(11)Jaffé, G.Ann. der Phys. 42 (1913), 303.
Lea, D. E.Proc. Cambridge Phil. Soc. 30 (1934), 80.
Bowen, J. S. and Cox, E. F.Phys. Rev. 51 (1937), 232.
Clay, J.Proc. Amsterdam Akad. 40 (1937), 824.

The total energy of the γ-radiation emitted from the active deposit of actinium

  • E. Kara-Michailova (a1)


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