Development of a simple-material discrimination method with three plastic scintillator strips: For easy inspection of mass-conserved system

Muon radiography based on the multiple Coulomb scattering of cosmic-ray muons has been performed. In this work, we discuss experimental results obtained with a cost-effective simple detection system assembled with three plastic scintillator strips. We counted the number of muons that were not largely deflected by restricting the zenith angle in one direction to 0.8°. The capability of the apparatus to discriminate Fe, Pb and C is presented. This principle can be applied to inspect large constructions with mass-conserved reactions such as a nuclear reactor. We show that materials lighter than Pb also can be discriminated with this system.