First transmission measurement at n_TOF: determination of the natCu total cross section over a wide energy range

Accurate and precise nuclear data are essential for the design, safety assessment, and performance evaluation of advanced nuclear energy technologies, particularly Generation IV fission and fusion reactors. In this context, copper plays a key role in systems such as the TAPIRO fast-spectrum research reactor, where sensitivity studies have shown a strong dependence on neutron-induced copper cross sections. However, the available experimental data for copper are scarce and significant inconsistencies exist among evaluated nuclear data libraries. To address these limitations, an experimental measurement campaign was proposed, including measurements at the n_TOF facility at CERN to improve neutron-induced copper cross sections. While radiative capture cross section measurements for 63Cu and 65Cu have already been performed, this thesis presents the measurement and analysis of the total cross section of natCu carried out in 2025 at n_TOF. It consisted of a transmission measurement, one of the first ever performed at the n_TOF facility. The experiment was carried out in the EAR1 experimental area, using a natural copper sample and a Low Mass Fission Chamber as a transmission detector. A comprehensive data analysis is presented, involving optimization studies aimed at improving data quality, so as to extract accurate natCu(n,tot) cross section. Thanks to the broad neutron energy spectrum available at the n_TOF facility, the extracted natCu(n,tot) cross section covers a wide energy range, from meV extending up to 30 MeV. The results are in agreement with the limited experimental data reported in the literature and evaluated nuclear data libraries, especially in the resonance region, confirming the quality of the measurements and the robustness of the analysis procedure.