Development of a prototype portable muography detect

Abstract

  We have developed a prototype portable muography detector to probe underground cavity and water distributions. The detector consists of two pieces of muon position sensitive detectors (mu-PSDs) having 140mm×140mm sensitive area. Each mu-PSD is composed of two arrays fabricated by 2 mm square plastic scintillating fibers (PSFs) to detect a crossing point of cosmic ray muon on two-dimensional plane. A multi-pixel photon counter (MPPC) is connected to each bunch of four PSFs. Total 64 MPPCs are controlled by an EASIROC module for voltage supply and signal readout. An operating test with β rays and cosmic ray muons was performed and satisfactory performance of position sensing was confirmed. Attenuation of cosmic ray muons by a reinforced column in a concrete building was successfully observed as the initial step of muography application.