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.