A simulations study of the muon response of the Iron Calorimeter detector at the India-based Neutrino Observatory

The magnetised Iron CALorimeter detector (ICAL), proposed to be built at the India-based Neutrino Observatory (INO), is designed to study atmospheric neutrino oscillations. The ICAL detector is optimized to measure the muon momentum, its direction and charge. A GEANT4-based package has been developed by the INO collaboration to simulate the ICAL geometry and propagation of particles through the detector. The simulated muon tracks are reconstructed using the Kalman Filter algorithm. Here we present the first study of the response of the ICAL detector to muons using this simulations package to determine the muon momentum and direction resolutions as well as their reconstruction and charge identification efficiencies. For 1–20 GeV/c muons in the central region of the detector, we obtain an average angle-dependent momentum resolution of 9–14%, an angular resolution of about a degree, reconstruction efficiency of about 80% and a correct charge identification of about 98%.