Measurement of the 197-Au(n,gamma ) cross section at n_TOF, - a step forward towards a new standard for capture cross section measurements

Abstract

The accurate knowledge of the 197Au(n,g ) reaction cross section is of great importance, since this reaction if often used as a reference in capture cross section measurements relevant to Nuclear Astrophysics, as well as for neutron flux determination in nuclear power reactors. With the aim of improving the accuracy of the neutron capture cross section on 197Au, extensive measurements were performed at the n_TOF facility at CERN with two detection systems: a total absorption calorimeter and a set of C6D6 detectors. The capture yield and the resonance parameters have been determined in the energy range from 1 eV to 5 keV and compared with evaluated data files. The present capture kernels are on average in good agreement with tabulated data, although sizable differences are observed for several resonances. A few new resonances are also reported.