Testing of various neutron filters in reference neutron field in LR-0 reactor for nuclear data validation and verification

Highlights: • Measurement of reaction rates in various neutron filters in reference neutron field. • Calculation of reaction rates in various neutron filters in reference neutron field. • Discrepancies between calculation and experiment. • Testing of ⁵⁵Mn(n,γ) cross section in various energy regions. Neutron activation analysis is the reference method used for offline determination of the neutron flux density in defined positions. It can be used in the nuclear energy industry-as well as in medical- or space applications. For accurate neutron flux evaluation, well-known and reliable cross sections are needed. In the thermal and fast energy region, many reliable monitoring reactions exists, however, in case of the epithermal and intermediate energy region, there are practically no dosimetry nuclear reactions sensitive specifically in this energy range. Due to this fact, both new data are being measured and methodologies are under development to describe and test this energy region. It was found that various neutron filters can be used to cut parts of neutron spectra and thus methodology based on spectrum filtering could potentially be employed to survey cross sections of interest. It this paper, the use of 3 different filters – B₄C, Cd, and In is studied, on the case of the ⁵⁵Mn(n,γ) reaction. Measured values of that cross section in the given filtered reference spectra are reported.