Measurement of β−-decay intensity distributions of several fission-product isotopes using a total absorption γ-ray spectrometer

Abstract A total absorption γ-ray spectrometer coupled to the 252 Cf-based INEL ISOL facility has been used in a program of systematic study of the distributions of β − -decay intensities of fission-product radionuclides. Cascade-summed γ-ray spectra measured with the system have been compared with the spectrum simulated from the corresponding decay schemes, as a test of the completeness and correctness of these schemes. New β − -decay intensity distributions have been deduced for the decay of these radionuclides. Radionuclides which have been studied in this manner include 89 Rb, 90g Rb, 90m Rb, 91 Rb, 93 Rb, 93 Sr, 94 Sr, 94 Y, 95 Sr, 95 Y, 138g Cs, 138m Cs, 139 Cs, 140 Cs, 141 Cs, 141 Ba, 142 Ba, 142 La, 143 Ba, 143 La, 144 Ba, 144 La, 145 Ba, 145 La, 145 Ce, 146 Ce, 146 Pr, 147 Ce, 147 Pr, 148 Ce, 148 Pr (2.0 min), 148 Pr (2.27 min), 149 Pr, 149 Nd, 151 Pr, 151 Nd, 152 Nd - 152 Pm (4.1 min.), 153 Nd, 153 Pm, 154 Nd, 154 Pm (1.7 min), 155 Nd, 155 Pm, 156 Pm, 157 Pm, 157 Sm, 158 Sm, and 158 Eu.