Radiography with cosmic-ray and compact accelerator muons; Exploring inner-structure of large-scale objects and landforms

Abstract

Cosmic-ray muons (CRM) arriving from the sky on the surface of the earth are now known to be used as radiography purposes to explore the inner-structure of large-scale objects and landforms, ranging in thickness from meter to kilometers scale, such as volcanic mountains, blast furnaces, nuclear reactors etc. At the same time, by using muons produced by compact accelerators (CAM), advanced radiography can be realized for objects with a thickness in the sub-millimeter to meter range, with additional exploration capability such as element identification and bio-chemical analysis. In the present report, principles, methods and specific research examples of CRM transmission radiography are summarized after which, principles, methods and perspective views of the future CAM radiography are described.

Simulated response of MuTe, a hybrid Muon Telescope

“…Projects like MU-RAY [19], ToMuVol [20], and DIAPHANE [21] use hodoscopes based on different detection technologies: emulsion plates, resistive plate chambers, micromegas, multi-wire proportional chambers, and scintillators, just to mention the most common ones. Each of these techniques has advantages and disadvantages: emulsion plate detectors [4,22] provide an excellent spatial resolution of the order of sub-microns, are passive, and easy to handle. On the other hand, they have short lifetimes, and it is not possible to discriminate the time-stamp of dynamic phenomena, because the recorded events accumulate in the plates.…”

Development of cosmic-ray muon spin rotation radiography to investigate chemical and physical states of steels in large-scale architecture

“…Cosmic-ray muon spin rotation radiography T. Fujimaki 3 (GeV to TeV) and low intensity (1/(cm) 2 /min in vertical direction) [11], a mixed charge state (60% µ + and 40% µ − ) and a partial spin polarization (-0.33 for µ + [12]). Because of high energy nature, a stopping distribution of the cosmic-ray muon in concrete extends from cm to a few km in depth.…”

“…For inspection of the inner structure of the large-scale architectures, a use of cosmic-ray muon is quite effective to observe large scale objectives and landforms [2]. The structure of the Second Pyramid of Giza was confirmed to have no hidden chambers by measuring directional variation of cosmic-ray muons incident to the detectors installed in the Pyramid [3].…”

Characterization and on-field performance of the MuTe Silicon Photomultipliers

“…Muography is a non-invasive technique for imaging anthropic and geologic structures [1][2][3][4][5][6][7][8][9][10][11][12] by measuring the crossing muon flux using sensitive hodoscopes made of nuclear emulsions [2,13], gaseous chambers [14][15][16][17] and scintillators [4,8,11,[18][19][20]. Scintillation hodoscopes provide flexibility on the implementation, low cost, and robustness against environmental variables such as humidity, temperature, and atmospheric pressure [21].…”