Estimation of 239Pu independent and cumulative fission product yields from the chain yield data using a Bayesian technique

Abstract

The independent and cumulative fission product yields (FPYs) are obtained by using the Bayesian technique based on the evaluated mass chain yield, where required constraints such as the normalization can be straightforwardly included. We apply this technique to the 239Pu FPY data at neutron incident energies of 0.5, 2.0, and 14 MeV, where the most updated mass chain yield ENDF/B-VII.1 data are available. The obtained yield data are compared with the evaluated values by England and Rider in ENDF/B-VI, and differences from their values are investigated. We show that the modern decay data used, such as branching ratios to ground and metastable states, cause differences in the evaluated individual and cumulative fission yields. © 2013 Taylor and Francis Group, LLC.