  We present the design of an instrument capable of measuring the high energy
($>$60 MeV) muon-induced neutron flux deep underground. The instrument is based
on applying the Gd-loaded liquid-scintillator technique to measure the rate of
high-energy neutrons underground based on the neutron multiplicity induced in a
Pb target. We present design studies based on Monte Carlo simulations that show
that an apparatus consisting of a Pb target of 200 cm by 200 cm area by 60 cm
thickness covered by a 60 cm thick Gd-loaded liquid scintillator (0.5% Gd
content) 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 discuss
the benefits of using a neutron multiplicity meter as a component of active
shielding in such experiments.
