Journal cover Journal topic
Geoscientific Instrumentation, Methods and Data Systems An interactive open-access journal of the European Geosciences Union
Geosci. Instrum. Method. Data Syst., 3, 29-39, 2014
http://www.geosci-instrum-method-data-syst.net/3/29/2014/
doi:10.5194/gi-3-29-2014
© Author(s) 2014. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
16 Apr 2014
Experimental study of source of background noise in muon radiography using emulsion film detectors
R. Nishiyama1, S. Miyamoto1, and N. Naganawa2 1Earthquake Research Institute, The University of Tokyo, Tokyo, Japan
2Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Japan
Abstract. The aim of this study is to ascertain and confirm the source of background noise in cosmic-ray muon radiography (muography) using emulsion film detectors. For this, we build two types of emulsion detectors with different momentum thresholds and perform test measurements of an actual geoscientific target. This experiment reveals that contamination of nonsignal particles with momenta of less than 2 GeV c−1 cause significant systematic errors for the density estimation of muography. Utilizing the results of precedent studies, we conclude that the origin of these low-momentum particles is either electromagnetic components of air showers or cosmic-ray muons scattered in topographic material. In this paper, we analyze the emulsion data in detail, including the film-inefficiency compensation and momentum selection by applying an upper bound to the chi-square distribution for the data.

Citation: Nishiyama, R., Miyamoto, S., and Naganawa, N.: Experimental study of source of background noise in muon radiography using emulsion film detectors, Geosci. Instrum. Method. Data Syst., 3, 29-39, doi:10.5194/gi-3-29-2014, 2014.
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