Determination of beta-decay intensities of ¹⁰⁷Mo using the Modular Total Absorption Spectrometer (MTAS)

Pandemonium effect is a potential systematic bias of beta feeding intensities in the decay measurements with high-resolution but low-efficiency detectors. This leads to the misinterpretation of the feeding intensities to high excited levels as to low-lying levels. Modular Total Absorption Spectrometer (MTAS), which has almost 99% gamma detection efficiency, is an ideal spectrometer to determine the true beta feeding intensities free from Pandemonium effect. 

  We have performed several MTAS experiments of fission products with mass from 99 - 107 at CARIBU (ANL). In this talk, I will present some preliminary data analysis result of ¹⁰⁷Mo, which has 1.4% cumulative fission yield of ²³⁵U but lack of experimental data in current ENSDF dataset. This new result will benefit the fundamental research of reactor anti-neutrino flux and decay heat calculation.