Linearity and saturation properties of Hamamatsu R5912-MOD photomultiplier tube for the ICARUS T600 light detection system

Abstract The ICARUS T600 liquid argon time projection chamber (LAr-TPC) will operate at shallow depth as far detector for the Short Baseline Neutrino (SBN) program at FNAL. A new scintillation light detection system, based on 360 Hamamatsu R5912-MOD Photomultiplier Tubes (PMTs), will allow to distinguish the actual beam related events from the huge cosmic background. A fundamental parameter for the correct reconstruction of events is the linearity of the photon detection system. The main response characteristics of the adopted PMT model as a function of the incident light intensity was evaluated. A comparison of the behavior at room and at cryogenic temperature was also carried out. Results confirm the conformity of this PMT model to the requirements of the ICARUS T600 light detection system.