Feasibility of multilayer neutron spectrometer with Backus and Gilbert approach using moderator-combination selection for energy-resolution optimization in Boron Neutron Capture Therapy irradiation field

The replacement of solid moderators of different thicknesses in a Bonner spectrometer is a conventional method. However, some studies have proposed the use of multilayer liquids as moderators. We are currently developing a cylindrical hemisphere-accurate remote multilayer spectrometer (CHARMS). As a novel method, we use the approach of Backus and Gilbert to select combinations of multiple moderators to achieve high-energy-resolution response functions. By simulation calculation, the performance of CHARMS with selection using the approach of Backus and Gilbert for evaluating the neutron spectrum in a Boron Neutron Capture Therapy (BNCT) irradiation field was confirmed to be better than that of the conventional method.