JUNO central detector and PMT system

Abstract

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi - purpose underground experiment and the largest liquid scintillator (LS) detector going for neutrino mass hierarchy, precise neutrino oscillation parameter measurement and studies of other rare processes which include but not l imit ed to solar neutrino, geo - neutrino, supernova neutrino and the diffuse supernova neutrino background. The 20 kt LS central detector (CD) of JUNO is the key of the whole facility. Parallel efforts and R&D activities addressing different aspects of the c entral detector are being actively pursued at different collaboration institutions. We present here details on the detector design and progresses. In another hand, how to build/install the largest LS detector also is a big challenge for the Φ 35.4 m acrylic sphere vessel with a stainless steel latticed shell and the ~17000 20’’ PMT and ~3 4 000 3’’ PMT. A nother key design for photon collection and detection is the PMT system, and here also will show a preliminary consideration of the final installation of the whole system including CD, PMT etc. A JUNO detector prototype with ~ 5 0 % photon - cathode coverage is under running and analysing. Goals of the prototype include testing different large area PMTs, testing electronics design and detector/data analysis algorit hm etc. Preliminary results including PMTs about the prototype will be presented here.