Measurement of Spectrum Averaged Cross Sections in LR-0 Benchmark Reference Neutron Field

TL;DR

This paper reports on the measurement and validation of spectrum averaged cross sections in the LR-0 benchmark neutron field, crucial for nuclear data accuracy and industrial applications, including contamination assessment.

Contribution

It provides a comprehensive set of low-uncertainty SACS measurements in the LR-0 neutron field for validation of nuclear data and assesses gamma-induced reaction impacts.

Findings

Gamma competition contributes up to 1% for 197Au(n,2n) reactions.

Large, validated SACS dataset enables improved nuclear data validation.

Gamma effects are negligible for most reactions.

Abstract

The measured and evaluated excitation functions are fundamental quantities that affect the accuracy of all calculations in nuclear applications. Some cross sections, such as 14N(n,p)14C, have added value for special applications, as these reactions may be responsible for possible contamination in industrial processes such as spent fuel reprocessing. For the validation of the evaluated cross sections, we can rely on the comparison of the calculated spectrum averaged cross sections (SACS) for the given neutron spectrum with the measured SACS value. The benchmark reference neutron field has been identified, characterized, and well validated in the LR-0 special core. A very large set of SACS measurements in the LR0 reference field is measured with low uncertainty, making it an excellent set for deconvolution codes validation. The impact of the gamma-induced reaction on the production yield of neutron-induced reactions was investigated for most of the benchmarked reactions. Gamma competition was found to contribute at most 1% for the 197Au(n,2n) reaction, while being substantially lower for other target isotopes and neutron-induced activation reactions.