摘要：The application of muon radiography will be greatly enhanced by the use of two muon sensor modules that save electric power consumption and are easily transportable.Muon sensor modules used for a volcano observation must have a low electric power consumption requirement and be both waterproof and portable.In this article, we discuss two candidate sensor modules: (1) a portable muon sensor module with wavelength-shifting (WLS) fibers and a multi-anode photomultiplier tube (MAPMT), and (2) a regular scintillator telescope with PMT complemented by a low-power Cockcroft-Walton circuit (CWPMT).A realistic telescope system consisting of a muon sensor module with MAPMT has been tested and found to consume 76 W, most of which (72 W) is used by the redundant electronic circuit required for pulse shaping; this could be modified to drastically improve the power consumption.In comparison, a muon telescope system with a CWPMT was found to consume 7.57 W.We also calculated the muon stopping length in SiO2 by means of a Monte-Carlo simulation.This calculation provided the average density structure along the muon path in rock, where the muon path length was shorter than 1.5 km, with an accuracy of about 5% during a 90-day measurement period by assuming a 1-m2 muon detector with an angular resolution of 25 mrad.
