Articles | Volume 2, issue 1
Geosci. Instrum. Method. Data Syst., 2, 29–34, 2013

Special issue: High energy geophysics: muon and neutrino radiography

Geosci. Instrum. Method. Data Syst., 2, 29–34, 2013

Research article 23 Jan 2013

Research article | 23 Jan 2013

Development and operation of a muon detection system under extremely high humidity environment for monitoring underground water table

H. K. M. Tanaka1 and A. Sannomiya2 H. K. M. Tanaka and A. Sannomiya
  • 1Earthquake Research Institute (ERI), University of Tokyo, Tokyo, Japan
  • 2Chigasaki Research Institute, J-POWER, Chigasaki, Kanagawa, Japan

Abstract. In order to investigate the complex nature of landslides triggered by rainfall, dynamic muon radiography of the motion of the underground water table is planned in a drainage tunnel drilled underneath an estimated fault plane. However, the humidity inside the tunnel is almost 100%. In order to suppress moisture effects, a scintillation counter with Cockcroft–Walton photomultipler tubes (CW-MPT) was developed and tested at the observation site located in Shizuoka Prefecture, Japan. The counter was stably operated for 38 days without gain degrading. Based on the result, we constructed a muon detection system with CW-PMTs at the same site and started operation runs. In this work, the data from borehole-based water gauge measurements of the underground water levels were analyzed and discussed. It was confirmed that the comparison between muon and borehole data would be useful.