Characterization of TRIGA RC-1 neutron irradiation facilities for radiation damage testing

TL;DR

This study thoroughly characterizes the neutron flux at TRIGA RC-1 reactor facilities using activation techniques and Bayesian unfolding, enabling precise dose assessments for radiation damage testing.

Contribution

It introduces a comprehensive method combining neutron activation and Bayesian unfolding to accurately measure neutron flux, spectrum, and distribution in irradiation facilities.

Findings

Total neutron flux measured within 2% uncertainty

Good agreement between measured and expected energy spectrum

Spatial distribution of neutron flux well characterized

Abstract

This paper presents the results of neutron flux measurements at two irradiation facilities of the TRIGA Mark II reactor at ENEA Casaccia Research Center, Italy. The goal of these measurements is to provide a complete characterization of neutron irradiation facilities for accurate and precise dose evaluation in radiation damage tests and, more generally, for all applications that need a good knowledge of neutron flux in terms of intensity, energy spectrum and spatial distribution. The neutron activation technique is used to measure the activation rates of several reactions, chosen so to cover the whole energy range of neutron flux spectrum. A multi-group neutron flux measurement is obtained through an unfolding algorithm based on a Bayesian statistical model. The obtained results prove that this experimental method allows to measure the total neutron flux within 2% statistical uncertainty, and to get at the same time a good description of its energy spectrum and spatial distribution.