Detecting supernova neutrinos with iron and lead detectors

Supernova (SN) neutrinos can excite the nuclei of various detector materials beyond their neutron emission thresholds through charged current (CC) and neutral current (NC) interactions. The emitted neutrons, if detected, can be a signal for the supernova event. Here we present the results of our study of SN neutrino detection through the neutron channel in Pb-208 and Fe-56 detectors for realistic neutrino fluxes and energies given by the recent Basel/Darmstadt simulations for an 18 solar mass progenitor SN at a distance of 10 kpc. We find that, in general, the number of neutrons emitted per kiloton (kTon) of detector material for the neutrino luminosities and average energies of the different neutrino species as given by the Basel/Darmstadt simulations are significantly lower than those estimated in previous studies based on the results of earlier SN simulations. At the same time, we highlight the fact that, although the total number of neutrons produced per kTon in a Fe-56 detector is more than an order of magnitude lower than that for Pb-208, the dominance of the flavor blind NC events in the case of Fe-56, as opposed to the dominance of nu(e) induced CC events in the case of Pb-208, offers a complementarity between the two detector materials so that simultaneous detection of SN neutrinos in a Pb-208 and a sufficiently large Fe-56 detector suitably instrumented for neutron detection may allow estimating the fraction of the total mu and tau flavored neutrinos in the SN neutrino flux and thereby probing the emission mechanism as well as flavor oscillation scenarios of the SN neutrinos.