Measurement and simulation of the muon-induced neutron yield in lead

A measurement is presented of the neutron production rate in lead by high energy cosmic-ray muons at a depth of 2850 m water equivalent (w.e.) and a mean muon energy of 260 GeV. The measurement exploits the delayed coincidences between muons and the radiative capture of induced neutrons in a highly segmented tonne scale plastic scintillator detector. Detailed Mo nte Carlo simulations reproduce well the measured capture times and multiplicities and, within the dynamic range of the instrume ntation, the spectrum of energy deposits. By comparing measurements with simulations of neutron capture rates a neutron yield in lead of (5.78 +0.21 −0.28 )× 10 −3 neutrons/muon/(g/cm 2 ) has been obtained. Absolute agreement between simulation and data is of order 25%.