Study of neutron transmission on 154,155,157Gd at neutron time-of-flight facility GELINA

The measurements of transmission on 154,155,157Gd for energies below 100 eV are discussed in this thesis. This study aimed at reducing the uncertainty to provide very accurate cross section data relevant for nuclear technology, nuclear medicine and detector development. In particular, I have analysed the transmission measurements carried out at the neutron time-of-flight facility GELINA at the EC-JRC-Geel (Belgium). The measurements were performed under different neutron irradiation conditions, using 9 different samples in order to minimize systematic uncertainties related to the samples, which was the main limitation in previous experiments. The samples analysed in this work are five isotopically enriched 154,155,157Gd metallic disks used in a previous capture measurement at the n_TOF facility at CERN and four samples consisting in an alloy of magnesium with a 0.25%wt of natGd. Transmission experiments were carried at a measurement station located at 10 m from the neutron source. I have performed the data reduction of these transmission measurements using dedicated software programs. The resulting cross sections data for 154,155,157Gd will be delivered to the publicly available experimental nuclear reaction database EXFOR.