Nuclear Physics Group 1C

Lepton Nuclear Physics Group



「極低放射能バックグラウンド 環境下における科学とその展望」ワークショップ

OTO Cosmo Observatory

The OTO Cosmo Observatory is the center of OTO Tentsuji tunnel which is located 100km south from RCNP. The maximum depth is about 470m. This is an ultra low-background laboratory with 4×10-7/cm2・sec for cosmic ray, 4×10 -5/cm2・sec for neutron flux, and about 10 Bq/m3 for radon concentration in the air.

Temperature and Moisture in the OTO Cosmo Observatory


ELEctron GAmma-ray Neutrino Telescope (ELEGANT V), whole detectors are surrounded by Lead and Copper (OFHC) shields, DC: Drift Chambers. PL:plastic scintillators, NaI: NaI scintillators, 100Mo source of double beta decay.