Characterization of the HZC Photonics XP82B20D and XP1805D Photomultiplier Tubes for Low-Temperature Applications

The IceCube Collaboration is investigating various types and manufacturers of photomultiplier tubes (PMT) for possible use in future optical modules. This report presents characterization results for two different types of HZC Photonics PMTs: the 3.5 inch XP82B20D and the 9 inch XP1805D. The results are in good agreement with the specifications as provided by the manufacturer. In addition, excellent noise behaviour is observed at the low temperatures relevant for possible use in IceCube optical modules.