Identifying Inconsistencies in Fission Product Yield Evaluations with Prompt Neutron Emission

TL;DR

This paper introduces a self-consistency analysis method for fission product yield evaluations, identifying anomalies and inconsistencies by comparing charge distributions and prompt neutron multiplicities with experimental data and simulations.

Contribution

It presents a novel approach to detect and analyze inconsistencies in fission yield evaluations using conservation checks and neutron multiplicity comparisons, improving data reliability.

Findings

Identified specific fission reactions with inconsistent yield data.

Proposed solutions to correct identified inconsistencies.

Validated the method against Monte Carlo simulations and experimental data.

Abstract

We present a self-consistency analysis of fission product yield evaluations. Anomalous yields are determined using a series of simple conservation checks and comparing charge distributions with common parameterizations. The total prompt neutron multiplicity as a function of product mass $\bar{\nu}_T(A)$ is derived directly from the independent fission product yields using average charge conservation. This method is checked against Monte Carlo simulations of the de-excitation of the fission fragments in a Hauser-Feshbach statistical decay framework. The derived $\bar{\nu}_T(A)$ is compared with experimental data, when available, and used to compare the prompt neutron multiplicity $\bar{\nu}$ for the various evaluations. Differences in $\bar{\nu}$ for each evaluation are investigated and possible sources are identified. We also identify fission reactions that are inconsistent with prompt neutron data and propose possible solutions to remedy the observed inconsistencies.