Underground horizontal ionization-neutron calorimeter-pairmeter

The necessity, prospects, and possibility of development of an underground multipurpose device for detecting high-energy penetrating particles (muons) are described. The use of lead as an absorber and plastic scintillators with gadolinium allow the simultaneous use of the device as an ionization-neutron calorimeter and a pairmeter for detecting nuclear and electromagnetic cascades from penetrating particles and separating ones from the others. The presented results of calculations of the pairmeter characteristics using the GEANT program show the possibility of estimating the muon energy from 100 GeV to 200 TeV with an accuracy of 40% for a version with 150 layers (2 cm lead + 1 cm plastic each).