Measurement of neutron total cross-section of Mg and MgF$_{2}$ at MONNET (JRC-Geel) from transmission with fine multi-scattering corrections

Abstract

Neutron-transmission measurements through samples of magnesium fluoride (MgF$_2$) and pure magnesium were performed to obtain the (n, tot) cross section for all isotopes involved, $^{19}$F and $^{24-26}$Mg. Lithium-glass detectors were used in conjunction with the neutron time-of-flight technique. The measurement campaign was performed at the MONNET fast-neutron source of the European Commission Joint Research Centre (JRC-Geel, Belgium). Highly precise corrections for multiple scattering were calculated using a sophisticated iterative method based on Monte Carlo simulations with the MCNP6.3 code, accounting for the effects of the experimental setup. With the SAMMY code, an R-Matrix analysis of the experimental data was performed. The extracted cross-sections, resonance spin and parity as well as the limitations of the method are carefully discussed.