The results of a Monte Carlo simulation study of the hadron energy response
for the magnetized Iron CALorimeter detector, ICAL, proposed to be located at
the India-based Neutrino Observatory (INO) is presented. Using a GEANT4
modeling of the detector ICAL, interactions of atmospheric neutrinos with
target nuclei are simulated. The detector response to hadrons propagating
through it is investigated 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
atmospheric neutrino interactions using events simulated with the NUANCE event
generator. The shape of the hit distribution is observed to fit the Vavilov
distribution, which reduces to a Gaussian at high energies. In terms of the
parameters of this distribution, we present the hadron energy resolution as a
function of hadron energy, and the calibration of hadron energy as a function
of the hit multiplicity. The energy resolution for hadrons is found to be in
the range 85% (for 1GeV) -- 36% (for 15 GeV).Comment: 14 pages, 10 figures (24 eps files
