Speaker
Description
The study of neutron-induced reaction cross sections for Mo isotopes is crucial for both research and applications in the nuclear industry, while they are vital for reactor safety. Neutron activation is a quite efficient technique for cross-section measurements; however, measurements involving short-lived products remain challenging. In this work, neutron capture cross-section measurements of reactions leading to short-lived products have been performed to improve data accuracy for stable $^{97}$Mo and $^{98}$Mo isotopes, which are currently limited by significant uncertainties. The activation measurements were carried out at the 3.5~MeV Tandem Van de Graaff accelerator at the ``MONNET'' facility of JRC-Geel in Belgium, while the $^{3}$H(d,n)$^{4}$He reaction was used to produce neutron beams with energies above 15~MeV. Thin metallic foils of enriched Mo, provided by the CERN n_TOF collaboration, were utilized. Reference samples of Al were used, and specifically the reference reaction $^{27}$Al(n,p)$^{27}$Mg, in the determination of the neutron flux at the target position. A newly installed automated pneumatic system was used for sample irradiation, transport, and radioactivity measurements to limit the decay of the radioactive products between irradiation and measurement. After the completion of each irradiation, the activity of the Mo targets and the reference foils was measured using a HPGe detector. The cross sections of the reactions $^{97}$Mo(n,p)$^{97\mathrm{m1}}$Nb and $^{98}$Mo(n,p)$^{98}$Nb, with half-lives of 58.7s and 2.86s, respectively, could be measured via the activation technique and were accurately determined, since the implementation of isotopically enriched targets prevents contamination from reactions of neighboring isotopes which produce the same residual nucleus. The new data are expected to reduce the discrepancies among existing data in the literature as well as evaluated nuclear data libraries and improve the reliability in applications requiring accurate neutron-induced reaction cross sections.