Visited the Under-Construction "Neutrino Detector" — Hyper-Kamiokande Project

KEK is developing a neutrino observation system for the Hyper-Kamiokande project and is installing a new intermediate detector, the IWCD.

The IWCD is a movable water Cherenkov intermediate detector designed to measure neutrinos shortly after production with high precision.

The IWCD is being placed about 1 km from J-PARC's neutrino source in Tokai-mura, Ibaraki Prefecture.

Its internal water tank is about 50 m deep, 10 m in diameter, with an effective volume of 800 t; the detector can sample the neutrino beam across about 30 m horizontally and about 40 m vertically.

Hyper-Kamiokande will observe artificial neutrinos sent 295 km from J-PARC to Kamioka, with observations planned to begin in fiscal 2028 to test CP symmetry violation.