The Front-End Electronics for the Hyper-Kamiokande Far Detector

A new front-end (FE) board has been designed and developed for the photomultipliers used in the Hyper-Kamiokande (HK) experiment, the new-generation water Cherenkov detector in Japan. The HK far detector will be instrumented by 20000 Hamamatsu R12860 photomultiplier tubes (PMTs), a new and improved version of the photosensors used in the previous experiment Super-Kamiokande (SK). These PMTs have been specially developed by Hamamatsu to create a sensor that improves the quantum efficiency and the ability to withstand higher pressures that will be present in HK. The new PMT electronics will be placed in a pressure vessel alongside the PMTs underwater. The use of new photosensors and the use of underwater vessels require the development of a new board with improved digitizing capabilities and a long life expectancy. This work describes the design and features of the new digitizer FE board designed for HK: the stringent requirements imposed by the collaboration, to how the board was designed, and concluding with the tests performed on the last proven prototypes before mass production.