The KM3NeT multi-PMT optical module

Abstract The optical module of the KM3NeT neutrino telescope is an innovative multi-faceted large area photodetection module. It contains 31 three-inch photomultiplier tubes in a single 0.44 m diameter pressure-resistant glass sphere. sensory device also comprising calibration instruments and electronics for power, readout data acquisition. capped with breakout-box connection to electro-optical cable power long-distance communication onshore control station. design was qualified first time deep sea 2013. Since then, technology has been further improved meet requirements scalability, cost-effectiveness high reliability. features sub-nanosecond timing accuracy dynamic range allowing measurement photon up cascade thousands photons, suited Cherenkov radiation induced water by secondary particles from interactions neutrinos energies GeV PeV. A distributed production model implemented delivery more than 6000 modules coming few years average rate 100 per month. In this paper review presented multi-PMT proven effective background suppression signal recognition sensitivity incoming direction photons.