Investigation of the influence of nuclear charge and beta-endpoint energy on the internal Bremsstrahlung of Sr-89 and Pm-147

Past experimental studies on the inner Bremsstrahlung (IB) emission from the forbidden beta-transitions have shown marked deviations from the theoretical calculations. In this paper, the IB spectra of the first forbidden beta-emitters of Sr-epsilon 9(38)(E(beta)(=)(max)1463 KeV) and Pm-61(147)(E-beta(max) =223 Key) are investigated. Also the effect of the nuclear charge and the beta-endpoint energy on IB process is investigated. As a result a good agreement between experiment and calculations of modified theory suggested by Konopski and Uhlenbeck was observed in a wide range of energy. Also it was observed that the Coulomb effect on IB process is higher in isotopes of higher values of nuclear charge (Z), and lower values of the beta-endpoint energy E-beta(max) (C) 2010 Elsevier Ltd. All rights reserved.