Optimization Study of Coupled Hydrogen Moderator with Extended Premoderator

摘要

We performed an optimization study of an extended premoderator (PM) for a coupled supercritical hydrogen (H_2) moderator in a lead reflected system. We found that the extended PM could eliminate a backside PM which had been believed to be indispensable from a neutronic point of view. This means that neutron beams can be extracted from both viewed surfaces of one moderator, so that two H_2 moderators can be replaced by one H_2 without sacrificing neutron intensity.