Hyper-Kamiokande: Neutrino Astrophysics and Status

The Hyper-Kamiokande (Hyper-K) project is a multi-purpose next generation neutrino experiment. The physics program includes accelerator neutrino, atmospheric neutrino oscillation measurement and proton decay. Neutrino astrophysics is also an important research topic. With its fruitful physics research programs, Hyper-K will play a critical role in the next neutrino physics frontier. It will also provide crucial information via astrophysical neutrino measurements, such as solar neutrino, supernova burst neutrinos and supernova relic neutrino. The Hyper-K far detector is a double-layered cylindrical shape, with 64 m in height and 71 m in diameter. It will be located deep underground to reduce cosmic-ray backgrounds, 600 m below Mt. Tochibora at Kamioka in Japan. The inner detector will be filled with ultra-pure water and surrounded by twenty thousand photosensors of 50 cm diameter and multi-PMT modules to detect water Cherenkov radiation from charged particles from the neutrino interactions. The detector will have a fiducial volume of 188 kt. In August 2025, the excavation of the access tunnels, detector cavern and surrounding caverns was completed. After installing the photosensors and system components, the data taking will start in 2028. Here, we will discuss the physics potential of Hyper-K neutrino astrophysics and construction status.