Simulation Studies for a Shallow Depth ICAL

The Iron CALorimeter (ICAL) is an upcoming neutrino detector at India-based Neutrino Observatory (INO). The observatory is planned to be located at Bodi West Hills, Madurai, under a mountain cover of \(\sim \)1 km. The rock overburden reduces the cosmic muon background by a factor of 10\(^{6}\) and also casts aside the hadronic component of cosmic ray background. It is possible to remove the hadronic component almost completely by a shallow depth (100 m) of the rock where the cosmic muon flux also reduces by a factor of 100. For achieving the same background reduction of cosmic muons at a shallow depth of 100 m, a veto detector with veto efficiency of 99.99% is required which appears to be feasible Panchal et al. (J Instrum 12:T11002, 2017 [1]). The neutral particles (neutrons and K\(^{0}_{L}\)) produced by muon-nuclear interaction can pass through the veto detector undetected which can mimic neutrino events in the ICAL detector. With this motivation, Geant4 based simulation studies have been performed to estimate such false positive event rate in the ICAL detector and the results are presented in this paper.