Measurement of the $^{232}$Th (n, $\gamma$ )/$^{58}$Ni (n, p) reaction rate ratio in the leakage neutron field of CFBR-II fast burst reactor

TL;DR

This study measures the reaction rate ratio of $^{232}$Th (n, $\gamma$) to $^{58}$Ni (n, p) in a fast reactor's neutron field, comparing experimental results with multiple nuclear data libraries.

Contribution

It provides experimental data on the reaction rate ratio in a fast reactor environment and compares it with several nuclear data evaluations.

Findings

Experimental reaction rate ratio is 4.37 with 3.9% uncertainty.

Results agree with ENDF/B-VII.1, JENDL-4.0, BROND-2.2 databases.

CENDL-3.1 database shows an 11.2% discrepancy.

Abstract

A ThO$_{2}$ sample and a nickel activation foil were irradiated in the leakage neutron field of CFBR-II reactor. The activities of the activation products were measured after irradiation to obtain the reaction rates. The normalized reaction rates were also calculated based on the ENDF/B-VII.1, CENDL-3.1, JENDL-4.0, BROND-2.2 databases. The experimental reaction rate ratio is 4.37 with an uncertainty of 3.9\% which is coincident with each of the ratios calculated based on the ENDFB-VII. 1, JENDL-4.0, BROND-2.2 databases, but is 11.2\% larger than that based on CENDL-3.1 database.