Speaker
Description
Neutron capture cross-section measurements are fundamental in the study of astrophysical phenomena, such as the slow neutron capture (s-) process of nucleosynthesis operating in red-giant and massive stars. One of the best suited methods to measure neutron capture (n,γ) cross sections over the full stellar range of interest is the time-of-flight (TOF) technique.
TOF neutron capture measurements on key s-process branching isotopes are very challenging due to the limited mass (~mg) available and the high experimental background arising from the sample activity. Overcoming the current experimental limitations requires the combination of facilities with high instantaneous flux, such as the CERN n_TOF facility, with detection systems with an enhanced detection sensitivity and high counting rate capabilities.
This contribution will present a brief summary about recent improvements at the n_TOF facility and new detection systems for (n,γ) measurements, such as i-TED, an innovative device which exploits the Compton imaging technique to reduce the dominant neutron scattering background. The discussion will be illustrated with results of the first measurement of the s-process branching-point reaction 79Se(n,γ).
Last, an overview will be given on the brand new high-flux n_TOF-NEAR activation station, and the future perspectives for new measurements of astrophysical interest involving unstable targets will be discussed.
