Performance studies on new 4" photomultiplier types intended for IceCube-Gen2 optical modules

Abstract

In the upcoming IceCube-Gen2 extension, the newly developed optical modules will include 4-inch PMTs. For this purpose, the manufacturers Hamamatsu and North Night Vision Technology have developed new PMT models to meet the requirements of the IceCube-Gen2 science case. The specifications include strict requirements on temporal resolution, detection efficiency, and dark noise. We summarize the efforts to measure these performance characteristics and show that both PMT models meet the performance specifications set by IceCube-Gen2. Prototype optical modules based on both PMT models will be deployed with the IceCube Upgrade in order to test them in situ and help decide on a vendor for the Gen2 extension.