Speaker
Description
The study of short-lived neutron induced reaction products is crucial for improving the nuclear reactor and astrophysical nucleosynthesis models. Short-lived residual nuclei only exist for a few minutes, or even seconds, and due to the difficulty in measuring short-lived activities, the data available in literature present high discrepancies and consequently can cause significant uncertainties in current nuclear evaluation databases. In this work, cross section measurements of neutron-induced reactions leading to short-lived products have been performed to improve data accuracy for the reactions 97Mo(n,p)97m1Nb, and 98Mo(n,p)98Nb isotopes, 197Au(n,3n)195Au and 197Au(n,n’)197mAu, 74Ge(n,p)74Ga and 76Ge(n,2n)75mGe, with half-lives ranging from as short as 3 seconds to approximately 500 seconds. The 3H(d,n)4He reaction has been used at the 3.5 MeV Tandem Van de Graaff accelerator at the “MONNET” facility of JRC-Geel in Belgium, to produce neutron beams with energies above 15 MeV for these measurements, carried out by means of the activation technique. A newly installed automated pneumatic system (Rabbit) was used for sample irradiation, rapid transport and subsequent radioactivity measurements to limit the decay of the radioactive products between irradiation and measurement. Cyclic activations were carried out to increase the counting statistics. Thin metallic foils of high purity Au, and highly enriched Mo and Ge samples, provided by the CERN n_TOF collaboration, were utilized. Reference samples of Al were used, and specifically the reference reaction 27Al(n,p)27Mg, in the determination of the neutron flux at the target position. After the completion of each irradiation, the activity of the targets and the reference foils were measured using HPGe detector. The newly obtained data would significantly reduce discrepancies among evaluated nuclear data libraries and contribute to improved reliability in applications requiring accurate neutron-induced reaction cross sections.