Speaker
Description
The Jiangmen Underground Neutrino Observatory (JUNO) is designed to determine the neutrino mass ordering and to perform precision measurements of the neutrino oscillation parameters. JUNO consists of a 20-kt liquid scintillator target monitored by a double calorimetry system consisting of 17596 20-inch large photomultiplier tubes (LPMTs) complemented by a 3-inch small photomultiplier tube (SPMT) array. To achieve JUNO’s target energy resolution of $3\%$ at $1\,$MeV a precise calibration of the PMT charge response, timing performance, and dark count rate (DCR) is required.\newline
This poster presents the calibration procedures and performance of the JUNO 20-inch LPMT, including $4939$ dynode-PMTs and $12657$ Micro-Channel Plate PMTs. The gain, relative timing offset, and transit time spread, which are critical for accurate energy and vertex reconstructions, are calibrated using the low-intensity laser data. Additionally, the LPMT DCR provides continuous low-intensity charge spectra that enable in-situ gain monitoring. The DCR-induced offset on the detected charge is monitored over time and subtracted for energy reconstruction.