Research

14 pages, 2838 KiB

Open AccessArticle

Geant4 Simulation of Muon Absorption in Concrete Layers

by David Joffe and Christian Perez

Instruments 2023, 7(2), 17; https://doi.org/10.3390/instruments7020017 - 31 May 2023

Viewed by 1808

Muography requires a detailed understanding of the absorption of muons in the material situated between the muon source and the detector. A large-statistics (>3 billion event) Geant4 simulation was run to simulate the absorption of muons in different thicknesses of concrete layers and [...] Read more.

Muography requires a detailed understanding of the absorption of muons in the material situated between the muon source and the detector. A large-statistics (>3 billion event) Geant4 simulation was run to simulate the absorption of muons in different thicknesses of concrete layers and to determine the effect of the material on the energies of muons that were not absorbed. The Geant4 simulation included a simple detector placed directly behind the absorbing material. A Geant4 simulation was also run for the same detector for alpha sources with no absorbing material and the results of this simulation were compared to the signals from the physical detector built in the laboratory and measured using standard alpha sources. The large-statistics simulations using muons of different energies were compared to the predictions of muon absorption from existing literature. The results of the simulations were in good agreement with both the measured signals from the laboratory as well as the predictions from the literature and the general method is found to be well-suited for studies used for muography involving material layers of uniform thickness. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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13 pages, 1895 KiB

Open AccessArticle

Characterization and On-Field Performance of the MuTe Silicon Photomultipliers

by Jesús Peña-Rodríguez, Juan Sánchez-Villafrades, Hernán Asorey and Luis A. Núñez

Instruments 2023, 7(1), 7; https://doi.org/10.3390/instruments7010007 - 22 Jan 2023

Viewed by 1248

Abstract

The Muon Telescope, MuTe, is an instrument for imaging volcanoes in Colombia. It consists of a scintillator tracking system and a water Cherenkov detector for particle energy measurement. The Muon Telescope operates autonomously in high-altitude environments where the temperature gradient reaches up to [...] Read more.

The Muon Telescope, MuTe, is an instrument for imaging volcanoes in Colombia. It consists of a scintillator tracking system and a water Cherenkov detector for particle energy measurement. The Muon Telescope operates autonomously in high-altitude environments where the temperature gradient reaches up to 10 °C. In this work, we characterize the telescope silicon photomultipliers’ breakdown voltage, gain, and noise for temperature variations spanning 0 to 40 °C. We demonstrate that the discrimination threshold for the Muon Telescope hodoscope must be above 5 photo-electrons to avoid contamination due to dark count, crosstalk, and afterpulsing. We also assess the detector counting rate depending on day-night temperature variations. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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10 pages, 8305 KiB

Open AccessArticle

Muon Radiography Investigations in Boreholes with a Newly Designed Cylindrical Detector

by Mariaelena D’Errico, Fabio Ambrosino, Luigi Cimmino, Vincenzo Masone, Marco Mirra, Giulio Saracino and Lorenzo Roscilli

Instruments 2023, 7(1), 2; https://doi.org/10.3390/instruments7010002 - 27 Dec 2022

Viewed by 1531

Abstract

Muons are constantly produced in cosmic-rays and reach the Earth surface with a flux of about 160 particles per second per square meter. The abundance of muons with respect to other cosmic particles and their capability to cross dense materials with low absorption [...] Read more.

Muons are constantly produced in cosmic-rays and reach the Earth surface with a flux of about 160 particles per second per square meter. The abundance of muons with respect to other cosmic particles and their capability to cross dense materials with low absorption rate allow them to be exploited for large scale geological or human-made object imaging. Muon radiography is based on similar principles as X-ray radiography, measuring the surviving rate of muons escaping the target and relating it to the mass distribution inside the object. In the course of decades, after the first application in 1955, the methodology has been applied in several different fields. Muography allows us to measure the internal density distribution of the investigated object, or to simply highlight the presence of void regions by observing any excess of muons. Most of these applications require the detector to be installed below the rock being probed. In case that possible installation sites are not easily accessible by people, common instrumentation cannot be installed. A novel borehole cylindrical detector for muon radiography has been recently developed to deal with these conditions. It has been realized with a cylindrical geometry to fit typical borehole dimensions. Its design maximizes the geometrical acceptance, minimizing the dead spaces by the use of arc-shaped scintillators. The details of the construction and preliminary results of the first usage are described in this paper. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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19 pages, 1840 KiB

Open AccessArticle

Atmospheric Muon Flux Measurement near Earth’s Equatorial Line

by Cristian Borja, Carlos Ávila, Gerardo Roque and Manuel Sánchez

Instruments 2022, 6(4), 78; https://doi.org/10.3390/instruments6040078 - 22 Nov 2022

Viewed by 3291

Abstract

We report measurements of muon flux over the sky of the city of Bogotá at 4°35′56′′ north latitude, 74°04′51′′ west longitude, and an altitude of 2657 m above sea level, carried out with a hodoscope composed of four stations of plastic scintillators located [...] Read more.

We report measurements of muon flux over the sky of the city of Bogotá at 4°35′56′′ north latitude, 74°04′51′′ west longitude, and an altitude of 2657 m above sea level, carried out with a hodoscope composed of four stations of plastic scintillators located equidistant over a distance of 4.8 m. Measurements were taken at different zenith (θ) angles within the range

{1.5}^{°} \leq θ \leq 90^{°}

, the muon flux data is statistically consistent with a

\cos^{2} θ

dependence, with a

χ^{2}

per degree of freedom near unity. If instead, we fit to a

\cos^{n} θ

we obtain

n = 2.145 \pm 0.046

with a lower

χ^{2}

per degree of freedom. Integrating the muon flux distribution as a function of the zenith angle over the solid angle of the upper Earth’s hemisphere allows an estimation of the atmospheric vertical muon rate at the altitude and latitude of Bogota obtaining a value of

255.1 \pm 5.8

m^{- 2} s^{- 1}

. This estimate is consistent with an independent direct measurement of the vertical muon flux with all detectors stacked horizontally. These measurements play a key role in the further development of detectors, aimed to perform muon imaging of Monserrate Hill, located in Bogotá, where the detectors will be placed at similar locations to those used in the present study. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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11 pages, 1612 KiB

Open AccessArticle

Muography for Inspection of Civil Structures

by Subhendu Das, Sridhar Tripathy, Priyanka Jagga, Purba Bhattacharya, Nayana Majumdar and Supratik Mukhopadhyay

Instruments 2022, 6(4), 77; https://doi.org/10.3390/instruments6040077 - 18 Nov 2022

Cited by 1 | Viewed by 2482

Abstract

Aging infrastructure is a threatening issue throughout the world. Long exposure to oxygen and moisture causes premature corrosion of reinforced concrete structures leading to the collapse of the structures. As a consequence, real-time monitoring of civil structures for rust becomes critical in avoiding [...] Read more.

Aging infrastructure is a threatening issue throughout the world. Long exposure to oxygen and moisture causes premature corrosion of reinforced concrete structures leading to the collapse of the structures. As a consequence, real-time monitoring of civil structures for rust becomes critical in avoiding mishaps. Muon scattering tomography is a non-destructive, non-invasive technique which has shown impressive results in 3D imaging of civil structures. This paper explores the application of advanced machine learning techniques in identifying a rusted reinforced concrete rebar using muon scattering tomography. To achieve this, we have simulated the performance of an imaging prototype setup, designed to carry out muon scattering tomography, to precisely measure the rust percentage in a rusted rebar. We have produced a 2D image based on the projected 3D scattering vertices of the muons and used the scattering vertex density and average deviation angle per pixel as the distinguishing parameter for the analysis. A filtering algorithm, namely the Pattern Recognition Method, has been employed to eliminate background noise. Since this problem boils down to whether or not the material being analyzed is rust, i.e., a classification problem, we have adopted the well-known machine learning algorithm Support Vector Machine to identify rust in the rusted reinforced cement concrete structure. It was observed that the trained model could easily identify 30% of rust in the structure with a nominal exposure of 30 days within a small error range of 7.3%. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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17 pages, 7022 KiB

Open AccessArticle

Gaseous Detectors for Field Applications: Quality Control, Thermal and Mechanical Stability

by Ádám Gera, Gábor Nyitrai, Gergely Surányi, Gergő Hamar and Dezső Varga

Instruments 2022, 6(4), 74; https://doi.org/10.3390/instruments6040074 - 10 Nov 2022

Cited by 3 | Viewed by 1592

Abstract

A cosmic muon imaging system is essentially a particle tracking detector as known from experimental High Energy Physics. The Multiwire Proportional Chamber (MWPC) once revolutionized this field of science, and as such it is a viable choice as the core element of an [...] Read more.

A cosmic muon imaging system is essentially a particle tracking detector as known from experimental High Energy Physics. The Multiwire Proportional Chamber (MWPC) once revolutionized this field of science, and as such it is a viable choice as the core element of an imaging system. Long term construction and operation experience was gathered from a Japanese–Hungarian collaboration that gave rise to the MWPC-based Muon Observatory System (MMOS), and is being used in Japan at the Sakurajima volcano. The present paper attempts to draw conclusions on the thermal and mechanical limits of the system, based on controlled measurements and detailed simulations. High temperature behavior and effects of thermal cycling and conditioning are presented, which appear to consistently allow one to propose quality control criteria. Regarding mechanical stability, the relation between gluing quality (tensile strength) and expected stress from vibration (during transportation) determines the safety factor to avoid damages. Both of these are presented and quantified in the paper using a conservative and austere approach, with mechanical simulations validated with experimental modal testing data. One can conclude that mechanical stress during industrial standard air freight shipping conditions is nearly a factor of three below the calculated maximum stress. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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23 pages, 44483 KiB

Open AccessArticle

Analysis of Secondary Particles as a Complement to Muon Scattering Measurements

by Maximilian Pérez Prada, Sarah Barnes and Maurice Stephan

Instruments 2022, 6(4), 66; https://doi.org/10.3390/instruments6040066 - 18 Oct 2022

Cited by 1 | Viewed by 1972

Abstract

Cosmic ray tomography is an emerging imaging technique utilizing an ambient source of radiation. One common tomography method is based on the measurement of muons scattered by the examined objects, which allows the reconstruction and discrimination of materials with different properties. From the [...] Read more.

Cosmic ray tomography is an emerging imaging technique utilizing an ambient source of radiation. One common tomography method is based on the measurement of muons scattered by the examined objects, which allows the reconstruction and discrimination of materials with different properties. From the interaction of air shower particles induced through cosmic rays with the material to be scanned, secondary particles, predominantly photons, neutrons and electrons, can be produced, which carry complementary information about the objects and their materials. However, this information is currently not fully exploited or only studied in coincidence with the incoming air shower particles. Therefore, this work presents a novel approach utilizing only the information from secondary particles to reconstruct and discriminate objects made out of a variety of materials. It also includes a detailed analysis of the kinematics of secondary particles and their dependency on material characteristics. In addition, a reconstruction algorithm to produce 3D maps of the examined volume from the measurement of secondary particles is introduced. This results in a successful reconstruction and differentiation of objects in various geometrical compositions. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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8 pages, 509 KiB

Open AccessArticle

DOME: Discrete Oriented Muon Emission in GEANT4 Simulations

by Ahmet Ilker Topuz, Madis Kiisk and Andrea Giammanco

Instruments 2022, 6(3), 42; https://doi.org/10.3390/instruments6030042 - 15 Sep 2022

Cited by 1 | Viewed by 2318 | Correction

Abstract

The simulation of muon tomography requires a multi-directional particle source that traverses a number of horizontal detectors of limited angular acceptance that are used to track cosmic-ray muons. In this study, we describe a simple strategy that can use GEANT4 simulations to produce [...] Read more.

The simulation of muon tomography requires a multi-directional particle source that traverses a number of horizontal detectors of limited angular acceptance that are used to track cosmic-ray muons. In this study, we describe a simple strategy that can use GEANT4 simulations to produce a hemispherical particle source. We initially generate random points on a spherical surface of practical radius by using a Gaussian distribution for the three components of the Cartesian coordinates, thereby obtaining a generating surface for the initial position of the particles to be tracked. Since we do not require the bottom half of the sphere, we take the absolute value of the vertical coordinate, resulting in a hemisphere. Next, we direct the generated particles into the target body by selectively favoring the momentum direction along the vector constructed between a random point on the hemispherical surface and the origin of the target, thereby minimizing particle loss through source biasing. We also discuss a second scheme where the coordinate transformation is performed between the spherical and Cartesian coordinates, and the above-source biasing procedure is applied to orient the generated muons towards the target. Finally, a recipe based on restrictive planes from our previous study is discussed. We implement our strategies by using G4ParticleGun in the GEANT4 code. While we apply these techniques to simulations for muon tomography via scattering, these source schemes can be applied to similar studies for atmospheric sciences, space engineering, and astrophysics where a 3D particle source is a necessity. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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19 pages, 1466 KiB

Open AccessArticle

Atmospheric and Geodesic Controls of Muon Rates: A Numerical Study for Muography Applications

by Amélie Cohu, Matias Tramontini, Antoine Chevalier, Jean-Christophe Ianigro and Jacques Marteau

Instruments 2022, 6(3), 24; https://doi.org/10.3390/instruments6030024 - 04 Aug 2022

Cited by 3 | Viewed by 1916

Abstract

Muon tomography or muography is an innovative imaging technique using atmospheric muons. The technique is based on the detection of muons that have crossed a target and the measurement of their attenuation or deviation induced by the medium. Muon flux models are key [...] Read more.

Muon tomography or muography is an innovative imaging technique using atmospheric muons. The technique is based on the detection of muons that have crossed a target and the measurement of their attenuation or deviation induced by the medium. Muon flux models are key ingredients to convert tomographic and calibration data into the 2D or 3D density maps of the target. Ideally, they should take into account all possible types of local effects, from geomagnetism to atmospheric conditions. Two approaches are commonly used: semi-empirical models or Monte Carlo simulations. The latter offers the advantage to tackle down many environmental and experimental parameters and also allows the optimization of the nearly horizontal muons flux, which remains a long-standing problem for many muography applications. The goal of this paper is to identify through a detailed simulation what kind of environmental and experimental effects may affect the muography imaging sensitivity and its monitoring performance. The results have been obtained within the CORSIKA simulation framework, which offers the possibility to tune various parameters. The paper presents the simulation’s configuration and the results obtained for the muon fluxes computed in various conditions. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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Review

Jump to: Research, Other

36 pages, 4043 KiB

Open AccessReview

Cosmic-Ray Tomography for Border Security

by Sarah Barnes, Anzori Georgadze, Andrea Giammanco, Madis Kiisk, Vitaly A. Kudryavtsev, Maxime Lagrange and Olin Lyod Pinto

Instruments 2023, 7(1), 13; https://doi.org/10.3390/instruments7010013 - 20 Mar 2023

Cited by 7 | Viewed by 5898

Abstract

A key task for customs workers is the interception of hazardous, illegal and counterfeit items in order to protect the health and safety of citizens. However, it is estimated that only a small fraction of cargo is inspected and an even smaller fraction [...] Read more.

A key task for customs workers is the interception of hazardous, illegal and counterfeit items in order to protect the health and safety of citizens. However, it is estimated that only a small fraction of cargo is inspected and an even smaller fraction of trafficked goods are detected. Today, the most widely used technology for scanning vehicles, ranging from vans and trucks to railcars, is

γ

ray and X-ray radiography. New technologies are required to overcome current technological shortcomings, such as the inability to detect the target material composition, the usage of harmful ionising radiation sources and the resultant low throughput. Cosmic ray tomography (CRT) is a promising technology for cargo screening. Cosmic ray muons have average energies of around 10,000 times larger than a typical X-ray and therefore can penetrate relatively large and dense materials. By analysing muon scattering, it is possible to identify materials hidden inside shielding that is too thick or deep for other imaging methods. CRT is also completely passive, exploiting naturally occurring secondary cosmic radiation, and is therefore safe for humans and animals. Contrary to conventional X-ray- or

γ

-ray-based imaging techniques, CRT also allows material differentiation and anomaly localisation within the cargo or vehicle through the provision of 3D images. This article reviews the current state-of-the-art technology in CRT, critically assessing the strengths and weaknesses of the method, and suggesting further directions for development. Full article

(This article belongs to the Special Issue Muography, Applications in Cosmic-Ray Muon Imaging)

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