Speaker
Description
Neutron capture cross sections are essential inputs for modeling stellar nucleosynthesis, particularly
for the slow neutron-capture (s-process.) The 14N(n,p)14C reaction is of particular interest, as it acts
both as a neutron poison and as a source of delayed neutrons through subsequent reaction chains.
An accurate determination of its Maxwellian Average Cross Section (MACS) is therefore essential
for reliable astrophysical models. However, the two most recent measurements exhibit non-
negligible discrepancies [1,2] and the precision achievable with time-of-flight measurements
remains limited, thus motivating the development of complementary approaches.
In this contribution, we present a new measurement, combining neutron activation and
Accelerator Mass Spectrometry (AMS) technique to investigate the 14N(n,p) 14C cross section with
high sensitivity and accuracy [3]. Several nitrogen-rich target materials have been irradiated with
quasi-Maxwellian neutron spectra at the n_TOF NEAR station, using different filter configurations
to probe the energy range relevant to s-process nucleosynthesis. Complementary irradiations at
LNL-INFN [4] are planned to further validate and benchmark the method. Following irradiation,
the freshly produced 14C atoms will be quantified at the CIRCE AMS facility [5], allowing
extraction of the corresponding MACS values.