Photon Detection System for DUNE Dual Phase*

The Deep Underground Neutrino Experiment (DUNE) is a dual-site experiment for long-baseline neutrino oscillation studies, and for neutrino astrophysics and nucleon decay searches. The Far Detector (FD) of DUNE will consist of four 10-kt LAr TPCs at 1300 km distance from the neutrino beam. The photon detection system (PDS) embedded within the detector adds precise timing capabilities for non-beam events, such as supernova burst neutrinos and proton decay. The ProtoDUNE Dual Phase (DP) detector consists of a 6x6x6 m³ LAr TPC and is crucial to demonstrate the viability of the technology on a massive scale. The PDS is formed by 36 8-inch cryogenic R5912-20Mod photomultiplier tubes (PMTs) from Hamamatsu. An LED-based fiber calibration system has been designed to check the PMT performance. The validation measurements of the PMT model will be reviewed as well as the characterization results of the PMTs used in ProtoDUNE-DP. The validation of the light calibration system will be also presented. In addition, the first simulation studies of the supernova trigger based on the light for DUNE-DP 10-kt FD will be shown.