The calculation of internal conversion coefficients of γ-rays

Abstract

The purpose of this paper is the calculation of theoretical values for the internal conversion coefficient I, of γ -rays converted K-and L 1 -shells. Hulme has obtained values for I in the K-shell assuming the radiating nucleus to emit the field of a dipole; while Taylor and Mott have assumed a quadripole field. The internal conversion coefficient has here been calculated for a number of values of hv for the L I -shell applying the theory developed by Taylor and Mott; the previous results for the K-shell have been extended and slight errors in the region of soft γ-rays have been corrected. Finally, the limiting values for very soft γ -rays have been obtained for both K-and L I -shells, with both quadripole and dipole fields. The calculations have been carried through using a value of the charge number Z = 84. The correction for RaB (Z = 82) would be small. Recently Taylor and Mott have extended their theory to account for the interaction between nucleus and the extranuclear electrons. They have shown that the "internal conversion coefficients" as calculated in H II and TM I are not a measure of the ratio Number of β-particles ejected in time dt /Number of γ -quanta leaving the nucleus in time dt , but, apart from a factor in general effectively unity, give I ≡ Number of β-particles ejected in time dt /Number of γ -quanta escaping from the system in time dt .