HyperKamiokande

Hyper-Kamiokande, or Hyper-K, is a next-generation water Cherenkov neutrino detector under construction at the Kamioka Observatory in Gifu Prefecture, Japan. It is designed to succeed the Super-Kamiokande detector and to enable a broad program of neutrino physics, proton decay searches, and astrophysical neutrino observations. The project aims to provide large-scale, high-statistics measurements that can address key questions about neutrino properties and fundamental interactions.

The detector consists of two large adjacent water tanks housed in a single cavern. It will contain about 0.52 million tonnes of ultra-pure water, with a fiducial volume of roughly 0.374 megatons, making it several times larger than Super-Kamiokande. Inside the tanks, arrays of photomultiplier tubes detect Cherenkov light produced by charged particles from neutrino interactions, enabling the reconstruction of particle type, energy, and direction. The design emphasizes improved light collection and angular resolution to enhance sensitivity to rare processes.

Hyper-K’s primary physics goals include precision measurements of neutrino oscillations using accelerator-generated neutrinos, with the aim of determining the CP-violating phase δCP and the neutrino mass ordering. The experiment will also study atmospheric neutrinos, search for proton decay in multiple channels, and observe neutrinos from astrophysical sources, including potential signals from galactic supernovae.

The project is an international collaboration led by Japanese institutions, with participating researchers from multiple countries. Construction and funding are planned to advance toward data-taking in the late 2020s, building on the legacy of Super-Kamiokande.