Silver is a very common material in archaeology, and its neutron total cross-section is crucial for neutron resonance transmission analysis (NRTA) in archaeometry. In this work, the neutron total cross sections of natural silver (^natAg) in the resonance region from 10 to 100 eV are measured at the China Spallation Neutron Source (CSNS) back-streaming neutron facility (Back-n). The neutron transmission rate of a 0.3 mm ^natAg sample is measured with a fission chamber equipped with ²³⁵U neutron converters. The neutron total cross-sections around resonance peaks at 16.25 eV, 30.35 eV, 40.15 eV, 41.35 eV, 44.6 eV, 51.25 eV, 55.45 eV, 70.75 eV, 87.3 eV are obtained. The cross-sections measured in this work are generally higher than previous measurements by G. Kim et al. and F. G. P. Seidl et al. These significant discrepancies are probably due to the resolution function of the facility, which is very sensitive to the resonance peaks.

The resonance parameters, i.e. the peak position of the resonances (E_res) and the neutron width (Γ_n)—of ¹⁰⁷Ag and ¹⁰⁹Ag, are extracted by fitting the transmission rate based on R-matrix theory. The extracted parameters E_res and Γ_n are generally in good agreement with the evaluations of ENDF/B-VIII.0 and CENDL-3.2, but the neutron width at 16.33 eV is significantly lower than the evaluations. The resolution function of the facility is considered to be the main reason of the inaccuracy. More accurate resonance parameters will be extracted in the future when a better control of the resolution function is achieved.

This work provides new cross-section data for the research and development of the NRTA technique at the CSNS Back-n facility and enriches the experimental dataset for the neutron total cross-section of natural silver. The dataset of this paper is available at https://www.scidb.cn/s/mu2Mjq.