Measurement of prompt neutron decay constant with spallation neutrons at Kyoto University Critical Assembly using linear combination method

Abstract

ABSTRACTThe robustness of the linear combination method to neutron source is demonstrated in the pulsed neutron source (PNS) experiment. The linear combination method reduces the spatial higher-mode (HM) components in neutron flux distribution by integrating the neutron counts obtained in the PNS experiment with the linear combination. In the previous study, we have confirmed the applicability of the linear combination method based on the PNS method conducted at Kyoto University Critical Assembly (KUCA) with a deuteron-tritium (D-T) neutron source. In this study, the PNS experiment is conducted at KUCA with 100 MeV proton accelerator and Pb-Bi target. The experiment is aimed at showing that the masking time dependence of the estimated prompt neutron decay constant is dramatically reduced by the linear combination method compared to the conventional method: these results demonstrate the linear combination method is applicable to spallation neutron source as well as D-T neutron source.