On-site underground background measurements for the KASKA   reactor-neutrino experiment
  On-site underground background measurements were performed for the planned reactor-neutrino oscillation experiment KASKA at Kashiwazaki-Kariwa nuclear power station in Niigata, Japan. A small-diameter boring hole was excavated down to 70m underground level, and a detector unit for $\gamma$-ray and cosmic-muon measurements was placed at various depths to take data. The data were analyzed to obtain abundance of natural radioactive elements in the surrounding soil and rates of cosmic muons that penetrate the overburden. The results will be reflected in the design of the KASKA experiment. 
H. Furuta, K. Sakuma, M. Aoki, Y. Fukuda, Y. Funaki, T. Hara, T.   Haruna, N. Ishihara, M. Katsumata, T. Kawasaki, M. Kuze, ...