Test and characterization of 400 Hamamatsu R5912-MOD photomultiplier tubes for the ICARUS T600 detector

ICARUST600 will be operated as far detector of the Short Baseline Neutrino program at Fermilab(USA), which foresees three liquid argon time projection chambersalong the Booster Neutrino Beam line to search for a LSND-like sterile neutrinosignal. The detector employs 360 photomultipliertubes, Hamamatsu model R5912-MOD, suitable for cryogenicapplications. A total of 400 PMTs were procured from Hamamatsu and tested at room temperature to evaluate the performance of the devices and their compliance to detect the liquid argonscintillation light in the T600 detector. Furthermore 60 units were also characterized at cryogenictemperature, in liquid argonbath, to evaluate any parameter variation which could affect the scintillation light detection. All the tested PMTs were found to comply with the requirements of ICARUST600 and a subset of 360 specimens was selected for the final installation in the detector.