Radiographic measurements of the internal structure of Mt. West Iwate
Cosmic-ray muon radiography has been studied as a potential method for the measurement of the internal structure of the active volcano Mt. West Iwate. We improved a cosmic-ray muon detection system built with a set of two position-sensitive segmented detectors by the multiplicity analysis of a soft-component background after passing through an Fe plate between the detectors. We measured the density of the region located 160m under the peak of Mt. Kurokura and compared to the gravimetric data.
Cosmic-ray muons as a radiographic probe provide useful information that complements the gravimetric data. We analyzed the
data to find time-dependent changes in the cosmic-ray muon intensity after passing through Mt. West Iwate, and a lower limit of 0.82% was found in Mt. Kurokura at the 90% CL. We discuss the possibility of cosmic-ray muon tomography with two or more
detection systems. / 830.00 Кб