Hadron energy response of the Iron Calorimeter detector at the India-based Neutrino Observatory

Abstract

The results of a Monte Carlo simulation studyof the hadron energy response for the magnetized Iron CALorimeterdetector, ICAL, proposed to be located at the India-based NeutrinoObservatory (INO) is presented. Using a GEANT4 modeling of the detectorICAL, interactions of atmospheric neutrinos with target nuclei are simulated.The detector response to hadrons propagating through it isinvestigated using the hadron hit multiplicity in the active detector elements.The detector response to charged pions of fixed energy is studied first,followed by the average response to the hadrons produced in atmosphericneutrino interactions using events simulated with the NUANCE event generator.The shape of the hit distribution is observed to fit theVavilov distribution, which reduces to a Gaussian at high energies.In terms of the parameters of this distribution, we presentthe hadron energy resolution as a function of hadron energy, andthe calibration of hadron energy as a function of the hit multiplicity.The energy resolution for hadrons is found to be in the range85% (for 1 GeV) – 36% (for 15 GeV).