The Hyper-Kamiokande (Hyper-K) experiment in Japan is an advanced neutrino observatory designed to explore fundamental physics questions, including neutrino oscillations, proton decay, and astrophysical neutrino sources. Located deep underground to reduce interference from cosmic rays, Hyper-Kamiokande consists of a massive tank filled with ultrapure water.
When neutrinos interact with the water molecules, they produce Cherenkov radiation, which is detected by an array of over 400 large photomultiplier tubes (PMTs) for precise measurement of neutrino events.

To meet the specific demands of this experimental setup, CAEN has provided a reliable underwater power supply system composed of 911 Low Voltage and High Voltage boards. The
Low Voltage boards supply stable power to the High Voltage modules and digitizers, supporting both the power needs of the PMTs and data acquisition electronics. The High Voltage system, the A7026HK module (24 channels, 2.6 kV/500 μA each), is designed specifically to power the PMTs that capture Cherenkov light, ensuring a consistent and reliable signal.

Each component is engineered for high reliability with redundancy across both the high and low voltage systems. This redundancy ensures that even if a single component fails, the system remains operational, which is essential given the tank’s human-inaccessible environment. CAEN’s robust design also allows for extended maintenance intervals, a critical requirement for the remote and submerged setup of the Hyper-K detector, enhancing the stability and operational longevity of this groundbreaking experiment.