The neutron zero degree calorimeter for the ALICE experiment

In this paper, we present the performance of the Neutron Zero Degree Calorimeter (ZN) for the ALICE experiment. The ZN is a quartz-fiber spaghetti calorimeter, which will measure the energy of the spectator neutrons in heavy ion collisions at the CERN LHC. Its principle of operation is based on the detection of the Cherenkov light produced by the charged particles of the shower in silica optical fibers, embedded in a W-alloy absorber. The detector was tested at CERN SPS using positive hadron and positron beams with momenta ranging from 50 to 150 GeV/c. The response of the calorimeter, the energy resolution, the localizing capability, the signal uniformity and the transverse profile of the detectable hadronic shower are presented.