KeV-neutron capture cross-section measurement of ¹⁹⁷Au with a Cr-filtered neutron beam at the ANNRI beamline of MLF/J-PARC

Cr-filtered keV-neutron experiments were performed in the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) beamline in the Materials and Life Science (MLF) facility of the Japan Proton Accelerator Research Complex (J-PARC) to measure the neutron capture cross-section of ¹⁹⁷Au. The energy range of the neutron filtering system at ANNRI was extended through the use of 15 cm of ^natCr as filter material to tailor quasi-monochromatic neutron peaks with averaged neutron energies of 133.4 and 45.0 keV. The performance of the ^natCr filter assembly was evaluated by means of experimental capture and transmission analyses, together with the use of Monte-Carlo simulations. The present ¹⁹⁷Au neutron capture cross-section results provide agreement within uncertainties with the JENDL-4.0 evaluated library and the IAEA standard data library further demonstrating the capabilities of the neutron filtering system at ANNRI. (author)