A Neutron Multiplicity Meter for Deep Underground Muon-Induced High Energy Neutron Measurements

摘要

We present the design of an instrument capable of measuring the high energy($>$60 MeV) muon-induced neutron flux deep underground. The instrument is basedon applying the Gd-loaded liquid-scintillator technique to measure the rate ofhigh-energy neutrons underground based on the neutron multiplicity induced in aPb target. We present design studies based on Monte Carlo simulations that showthat an apparatus consisting of a Pb target of 200 cm by 200 cm area by 60 cmthickness covered by a 60 cm thick Gd-loaded liquid scintillator (0.5% Gdcontent) detector could measure, at a depth of 2000 meters of water equivalent,a rate of $70\pm8$ (stat) events/year. Based on these studies, we also discussthe benefits of using a neutron multiplicity meter as a component of activeshielding in such experiments.