Cosmic Ray Muography

Description

Muography is a term recently introduced to embrace different techniques that profit from the penetration capability of the muon component of cosmic rays to investigate the interior of large and otherwise inaccessible structures. Primary cosmic rays — high energy particles originating outside the solar system — interact with the Earth atmosphere and generate muons, particles with the same electric charge as the electron, while their mass is 200 times heavier. At the Earth's surface, cosmic muons represent the most abundant component of cosmic rays, and favourably, they can feature energies sufficiently high to penetrate even thick and dense materials, giving the opportunity of unveiling the internal structure of large volumes. Muography was made possible by the development of detectors in the field of particle physics, allowing the exploitation of this natural source for imaging in a vast variety of fields, characterizing this technique as truly interdisciplinary, and leading to significant advances in several disciplines. This book tries to cover all aspects of this methodology, with the different chapters pointing to the general physics principles, to the technological and image reconstruction challenges and to the principal applications in several fields, such as archaeology and geology but also civil and industrial applications. The volume contributors had omitted unnecessary technical details, while focusing on the main features and methodologies. Hence, the book not only targets scientists working in the field but also non-specialists, who might enjoy the reading as a tutorial. Contents Chapter 1. Historical Developments and Perspectives of Muography 1. Introduction 2. Historical Developments and Pioneering Works 2.1. Early works 2.2. Revealing the internal structure of a volcano 2.2.1. Phreatic explosion 2.2.2. Magma convection 2.3. Real-time monitoring and multiple exposure muography 2.4. From 2D imaging to 3D reconstruction 2.5. Mobile muography 2.5.1. Airborne muography 2.5.2. Automobile muography 2.6. Usage of AI 2.7. Muography art 3. Perspectives 3.1. From land to sea 3.2. From Earth to outer space 4. Conclusion References Chapter 2. Cosmic Ray Muons 1. Introduction 2. The Primary Cosmic Radiation 3. Propagation of the Cosmic Radiation in the Atmosphere 4. Secondary Particles 5. Muon Production 5.1. Main channels 5.2. Muon production via photopion production 5.3. Direct photoproduction of muon pairs 5.4. Muon production by neutrinos 6. Muon Decay 7. Muon Interactions and Energy Losses 7.1. General comments 7.2. Ionization losses of muons 7.3. Muon Bremsstrahlung 7.4. Direct electron pair production by muons 7.5. Direct muon pair production by muons, muon trident events 7.6. Photonuclear interactions of muons 8. Summary of Muon Reaction Probabilities and Energy Losses 9. Zenith Angle Dependence of the Atmospheric Column Density 9.1. Flat earth approximation 9.2. Curved earth atmosphere 10. Muon Data at Sea Level 10.1. General comments 10.2. Muon flux and energy spectra References Chapter 3. Principle of Cosmic Muography — Techniques and Review 1. Introduction 2. Muon Interactions with Matter 2.1. Energy losses 2.2. Multiple Coulomb scattering 3. Muography Techniques 3.1. Transmission technique 3.2. Absorption technique 3.3. Multiple Coulomb Scattering (MCS) technique 3.4. Muon-induced fission neutrons 3.5. Final remarks 4. Summary Appendix: Examples of Tomographic Imaging with MSC Technique and MLEM Reconstruction Acknowledgments References Chapter 4. Emulsion Detectors for Muography 1. Introduction 2. Emulsion Detectors 2.1. History 2.2. Detection mechanism 2.3. Performance 2.4. Scanning system 2.5. Measurement procedure 3. Development of Emulsion Detector for Muon Radiography 3.1. Emulsion stability 3.2. Background rejection 3.2.1. Selection of tracks during observation 3.2.2. Removal of low-energy noise 3.2.3. Effects of environmental radiation 3.3. Mass production 3.4. Scanning speed 4. Summary References Chapter 5. Real-time Detectors for Muography 1. Real-time Detectors 1.1. Scintillator-based detectors 1.1.1. Scintillation process 1.1.2. Photodetection 1.1.3. Examples 1.2. Gas detectors 1.2.1. Examples 1.2.2. Cherenkov detectors 1.3. Portable devices References Chapter 6. Three-Dimensional Muography and Image Reconstruction Using the Filtered Back-Projection Method 1. Introduction 2. Filtered Back-Projection for Multi-Directional Muography 2.1. Projection and back-projection 2.2. Filtered back-projection 2.3. Three-dimensional imaging with the cone-beam approximation 2.4. Application to multi-directional muographic imaging of a volcano 3. Performance Estimation with a Forward Modeling Simulation 3.1. Models, assumptions, parameters, and procedures 4. Results 5. Discussion 6. Conclusions and Future Prospects Acknowledgments References Chapter 7. Muography and Geology: Volcanoes, Natural Caves, and Beyond 1. Introduction 2. Muography Basics: Direct and Inverse Problem 2.1. Detecting muons: The direct problem 2.2. From data to images: The inverse problem 3. From Volcanoes to Geotechnical Imaging 3.1. Pioneering works in Japan 3.2. Diaphane and the Soufrière of Guadeloupe 3.3. MURAVES (Vesuvius) and TOMUVOL (Puy-de-Dôme) 3.4. Nuclear reactor investigation 4. From Natural Caves to Civil Engineering 4.1. The underground Mont Terri laboratory: Geological muography 4.2. Observation of Sudden Stratospheric Warmings event 4.3. Tunnel-boring machines 5. Conclusions References Chapter 8. Muography and Geology: Alpine Glaciers 1. Introduction 2. Emulsion Detectors and Field Observations 3. Data and Analysis 4. Results 5. Discussion 6. Future Prospects References Chapter 9. Muography and Archaeology 1. Introduction 2. Egyptian Pyramids 2.1. Khafre’s Pyramid 2.2. ScanPyramids 2.2.1. Bent Pyramid 2.2.2. Khufu’s Pyramid 3. Ancient Mesoamerican Civilization 3.1. Pyramid of the Sun 3.2. Copan 4. Ancient Civilization in ItalyIn the underground areas of Italian cities 4.1. Subterranean remains 4.2. Underground cavities 4.3. Ancient mines 5. Japanese Burial Mounds 6. Summary References Chapter 10. Civil and Industrial Applications of Muography 1. Introduction 2. Muon Geotomography for Subsurface Exploration 2.1. Mining industry 2.2. Tunnels and other underground civil engineering structures 2.3. Portable borehole muon detectors for industrial and civil applications 3. Muography of Civil and Industrial Structures 3.1. Monitoring of blast furnaces 3.2. Inspection of the Unit-1 reactor at Fukushima Daiichi Nuclear Power Plant 3.3. Exploring the inner structure of buildings 3.3.1. Search for a iron hoop inside the Florence Cathedral’s Dome 3.3.2. Detection of rebars in concrete 3.4. Non-destructive testing of industrial equipment using muon radiography 4. Nuclear Controls 4.1. Inspection of dry storage casks 4.2. Imaging of intermediate level nuclear waste drums 4.3. Vehicle and cargo scanning for nuclear contraband 4.4. Search for radioactive sources in scrap metal 5. Muon Metrology for Civil and Industrial Applications References