Particle simulation software is essential for the development and validation of theoretical prototypes in a myriad of physical appplications. The Geant4 simulation toolkit provides precise particle transport and matter interaction simulations in a controlled setting. The interpretation of simulated results is intimately linked to the level of detail represented in the simulation itself, including the ability of the simulation framework to create detailed geometries. Yet, rendering such highly detailed geometries is a daunting task in Geant4, where high-variance scenes must often be manually coded. Potential geometrical errors increase the time required for this coding procedure, and thus in-depth knowledge of the underlying simulation engine in Geant4 is needed.

This research proposes Blender2Geant4 (B2G4), a novel framework which transplants 3D scenes from Blender into Geant4 for synthetic data generation. This was achieved by synergizing the descriptive 3D modelling tools in Blender with the simulation capabilities of Geant4. The ability to import, arrange, and manipulate 3D objects in Blender permits the creation of highly detailed and varied scenes: users can easily create sophisticated geometries by using drag-and-drop placement, shape variance randomization, and intuitive material assignments. The suite of functionalities defined in B2G4 lexically translates geometry facets from Blender into a readable format for Geant4, enabling the automated export and import of scenes with minimal manual input. Hence, the B2G4 framework enables automated mass production of corrected 3D scene variations with precise annotations and geometrical consistency checks. The B2G4 framework is designed as an all-purpose geometry creation interface to reduce the complexity of simulation scenes in Geant4 for a variety of physical applications. The applicability of B2G4 in a muon tomography setup is highlighted with a set of procedurally generated 3D scenes.

How to cite: Bueno, A., Sattler, F., Perez Prada, M., Stephan, M., and Barnes, S.: B2G4: A synthetic data pipeline for the integration of Blender models in Geant4 simulation toolkit., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6638, https://doi.org/10.5194/egusphere-egu23-6638, 2023.

Muography is an inherently multidisciplinary field, and as such presents a wide range of practical and methodological challenges. Regarding instrumentation, the environment drastically differs from the high energy physics laboratory conditions. In addition, the choice of measurement location and the instrument with the most suitable parameters is far from obvious: one needs to balance between improving detection sensitivity (e.g. moving closer to the target) and local possibilities (accessibility, safety). The presentation gives an overview of successful implementations, with detailed case examples with participation of Wigner Research Centre for Physics. Detectors on the surface need to cope with daily thermal cycling and intermittent high humidity periods, as apparent at the Sakurajima Muography Observatory, or imaging a medieval castle in Sicily. Underground detectors on the other hand require fast and efficient installation, since such environments -- particularly mining -- safety concerns limit personal access. Examples include mines from Finland and Bosnia and Herczegovina. From the point of view of methodology, the presentation will discuss the data quality requirement for three dimensional density map reconstruction (tomography). In case of a complicated karst structure, low density zones identified by muon tomography were confirmed by drilling.

How to cite: Varga, D., Surányi, G., Hamar, G., Nyitrai, G., and Balázs, L.: Challenges, best practices and case examples in muon imaging, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11260, https://doi.org/10.5194/egusphere-egu23-11260, 2023.

Archémuons is a collaborative project between the Institute of Physics of the 2 Infinities of Lyon (IP2I Lyon), the Laboratory of Geology of Lyon (LGL) and the ArchéOrient Laboratory. The three laboratories will perform surveys at the Palais du Miroir of the Gallo Roman Museum of Vienne in France. The goal of the project is to evaluate how geology surveys (electric resistivity, gravimetry, seismometry) synergize with muon tomography for near surface underground studies. The foundation of the Palais du Miroir building and the surrounding extensive network of galleries provide a rich yet challenging set of targets to investigate. The controlled/confined environment provides opportunities to test different analysis and imaging techniques as well as new detector geometries, scintillation materials and a new portable prototype compact detector that combines Cherenkov detection with a scintillator based trajectograph which will be deployed and tested on site. In November 2022 the project kickstarted with an electric resistivity survey of the surface above the gallery where the muon detector will be hosted. In parallel a first set of measurements was acquired with a small scintillation detector as a proof of concept and for a first evaluation of the ground overburden. We will present the current status of this project as well as a preliminary result acquired by the time of the EGU2023 General Assembly.

How to cite: Avgitas, T. and Marteau, J.: Near surface muography studies at the Gallo-Roman archaeological site of Vienne, France., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1843, https://doi.org/10.5194/egusphere-egu23-1843, 2023.

The employment of remote sensing (RS) survey methods, in particular of close-range methods, as part of the muon imaging process is becoming a topic of growing interest. Use of light detection and ranging (LiDAR) methodologies, like terrestrial laser scanner (TLS), together with the unmanned aerial vehicles digital photogrammetry (UAV-DP) and satellite data are proving to be fundamental tools to carry out a reliable muographic measurements campaign. The main purpose of this presentation is to show the importance of correctly plan TLS and UAV-DP field surveys for muon radiography applications. To this aim, a real case study is presented: the research of hidden tombs at the Volumni Hypogeum archeo-geosite (Umbria, Italy). A high-resolution digital terrain model (DTM) and three-dimensional models of the surface/sub-surface were created merging different RS survey methods. The muon flux transmission was measured using the MIMA detector prototype (Muon Imaging for Mining and Archaeology). The latter is a small tracker (0.5 x 0.5. x 0.5 m³) developed by the physicists of the National Institute of Nuclear Physics (INFN), unit of Florence, and the Department of Physics and Astronomy of Florence. The measured muon flux was compared to the simulated one, obtained using the three-dimensional created environment, to infer information about the average density of the studied target along the various LoS (line of sight). The study highlights the importance of correctly carrying out the TLS and UAV-DP survey to make reliable hypotheses and decisions throughout the muographic measurement campaign. Furthermore, we pointed out how the precision of the tridimensional data can bias the muon imaging results.

How to cite: Beni, T., Borselli, D., Bonechi, L., Lombardi, L., Gonzi, S., Ciaranfi, R., Bongi, M., Ciulli, V., Fanò, L., Frosin, C., Paccagnella, A., Melelli, L., Turchetti, M. A., D'Alessandro, R., Gigli, G., and Casagli, N.: Close-range methods for muon imaging applications: a case study from Italy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2339, https://doi.org/10.5194/egusphere-egu23-2339, 2023.

Muon radiography, or muography, is a non-invasive technique allowing imaging of the interior of large structures (target) thanks to the study of the absorption of atmospheric muons in materials. The muons absorption effect depends not only on the thickness, but also on the density of the target. Careful comparisons of the muographic results with simulations taking into account a precise description of the target's geometry, allow estimating the two dimensional distribution of the average density of the structure under study as seen from the measurement point of view. In this presentation an application in the geological field for the research and localization of low density anomalies attributable to cavities inside an abandoned mine will be shown. The aim of the study is to identify and locate areas that might be responsible for the production of anomalous concentrations of radon gas inside underground mining sites used for touristic itineraries. Radon is a natural radioactive gas that exposes tourists to ionizing radiation. Radon decay products are the second cause of lung cancer after smoking. It is important therefore to understand where the radon gas comes from before moving through the different galleries. The case study is the Temperino mine near Campiglia Marittima (LI-Italy). Here, the mining activity ended in 1980 and it was primarily focused on the extraction of copper, silver lead and zinc minerals. The area to be explored with muon radiography is part of an area dating back to the Etruscan period that has not yet been completely mapped and that is located above the tourist path of the Temperino mine at a depth of about 40 m from the surface of the hill above. Any nearby cavity could represent a prime conduit that brings radon gas into the tourist trail. The identification and localization in space of these ancient excavations is also interesting from a geological and archaeological point of view. The detector employed for the muographic measurements reported in this presentation, designed in Florence by the National Institute of Nuclear Physics (INFN) and the Department of Physics and Astronomy, is called MIMA (Muon Imaging for Mining and Archaeology) and has cubic shape and approximate dimensions of (50x50x50) cm³. MIMA is equipped with a special protective aluminum mechanism that allows its altazimuth orientation.

How to cite: Borselli, D., Beni, T., Bonechi, L., Bongi, M., Brocchini, D., Casagli, N., Ciaranfi, R., Ciulli, V., D'Alessandro, R., Dini, A., Frosin, C., Gigli, G., Gonzi, S., Guideri, S., Lombardi, L., Paccagnella, A., and Vezzoni, S.: Three-dimensional localization of Radon source conduits inside the Temperino mine (Tuscany-Italy) with the muon radiography technique, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2352, https://doi.org/10.5194/egusphere-egu23-2352, 2023.

Tunnelling and underground mining face many risks threatening underground operations. Such hazards include sudden incidents of dangerous and violent rock bursts and cave-ins. The likelihood of these disastrous events increases as operations go deeper and the in-situ stresses increase. Triggers leading to such accidents can be regional seismic events related to faults and tectonically active contacts between rock types (e.g., dyke contacts). Therefore, it is paramount to know the locations of such pre-existing brittle rock structures, understand their 3D extent, and monitor their changes in time. This allows proactive measures to be taken and stresses to be mitigated before disastrous events occur.

Muography is a novel and passive method for imaging rock densities. Muographical techniques can image and distinguish faults and dykes as long as their densities differ from the surrounding rock. Such anomalies are identified by collecting data and statistics on muons - elementary particles which form in the atmosphere and, at near lightspeed, penetrate all matter. The most energetic ones travel over 1 km in rocks. The number of muons coming from each direction reveals the density of the rock column the muons traversed through.

Muography is conceptually akin to X-ray imaging: In both, the formed image relates to the density profile of the target, i.e., a higher-density medium stops more X-rays and muons than a lower-density medium. Images are reconstructed based on the attenuation of natural background radiation flux. Muography can yield both 2D radiography and 3D tomography density images based on the number of survey locations. A third option, time-sequential (time-lapse) muography, allows long-term monitoring of the target rocks and can detect if any changes occur within it as a function of time. This type of imaging works in both radiographical and tomographical modes.

The flux of muons is high at ground level and decreases with depth as bedrock attenuates muons. This means that muon detectors located at shallow observation depths will be faster to record a statistically sound dataset and, as such, quicker in pinpointing any time-varying changes within the target density.

We propose that stationary muography arrays in underground settings could map potentially risky bedrock structures and monitor their density-affecting changes over time. E.g., hidden faults may become visible due to the passing of seasons or after the passing of substantial rainfall as the excess water percolates through the mechanically broken fractures. Another advantage of the time-sequential approach is that it reveals if the studied structure is stable and time-invariant, i.e., no ongoing processes affect its density. Therefore, we propose that applying muography in underground spaces improves understanding of the conditions of the rock body and, hence, increases safety.

We aim to conduct pilots for this application soon.

How to cite: Holma, M., Korteniemi, J., Kuusiniemi, P., and Zhang, Z.: Using a new geophysical tool for improving underground safety in mining and civil engineering: time-sequential muography, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3567, https://doi.org/10.5194/egusphere-egu23-3567, 2023.

Muography studies density differences within a medium using muons. They are elementary particles generated by primary cosmic rays as they collide with the matter. On Earth, muons are produced at ca. 15-25 km altitude in the upper atmosphere and penetrate down to ca. 1 km depth in the bedrock (with ever-decreasing numbers by increasing depth due to attenuation). Muons provide a powerful local probe to investigate density variations in any material they pass through (e.g., soils, rock, buildings, magma, or even the atmosphere itself).

Although muography has so far only been applied on Earth, several extra-terrestrial applications have recently been proposed. Many of them focus on possible lunar applications. However, first, we need to understand how muons are formed on the Moon.

As the Moon has no atmosphere the primary cosmic radiation hits the surface unobstructed. Muon production can thus be expected to occur within the lunar regolith, i.e., the ca. 5-10 m thick lunar "soil" layer. Regolith consists of crushed rock dust and shards (bulk density ca. 1.5 g/cm3 with rock fragments, e.g., lunar anorthosite 2.7 g/cm3 [1]).

We simulated lunar muon production using silica (SiO2, density 2.65 g/cm3) as it is easy to construct in a simulation. Silica is a common constituent in silicate minerals, which are abundant also on the Moon, although free quartz itself is rare there. It is also more realistic than water, which we used earlier for testing and developing the simulations' routines and methods [2]. Simulated primary cosmic-ray particles were protons with two energies: 1 PeV and 3 PeV. Protons were chosen since they dominate up to the knee region and are the most relevant primary particles for these studies. The incoming proton zenith angle was selected to be uniform and limited to 75 degrees. Simulations were performed by the Fluka simulation package using the CSC (IT Center For Science Ltd., Finland) supercomputer.

Our preliminary results suggest that about 50% of the muons are generated in the topmost 125 cm. About 90% of the muons are generated in the range of 275 cm. Interestingly, this depth is almost independent of the primary-particle energy. Hence, if these quartz-based simulations are taken as a simplified model for lunar muon production, all muons are generated within just some metres of material.

Consequently, lunar muography should not only work, but it should work for small targets quite close to the surface. Muography could be applied, e.g., to identify H2O ice sources at elevated locations (e.g., crater walls, central peaks, hills, and cliffs), investigate the structural integrity of lunar lava tubes (which are often suggested as possible human habitation sites), and monitoring structural weaknesses of lava tubes or artificial in-situ constructs.

[1] C. Meyer, 2003. The Lunar Petrographic Educational Thin Section Set. https://www-curator.jsc.nasa.gov/education/lpetss/index.cfm.

[2] T. Enqvist, 2021. Exploration of Lunar In Situ Resources Can Be Conducted by Applying Density-Sensitive Cosmic-Ray-Based Geophysical Muon Imaging Method Called Muography. ST.040. SEG 100 Conference.

How to cite: Kuusiniemi, P., Enqvist, T., Holma, M., Korteniemi, J., and Öhman, T.: Muon production in the lunar regolith: Opportunities for muon imaging in the Moon, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7336, https://doi.org/10.5194/egusphere-egu23-7336, 2023.

The Exploring the Great Pyramid (EGP) Mission is investigating using cosmic-ray muons to study the interior of the Great Pyramid of Giza with unprecedented resolution. Muon telescopes would collect data over a large angular range at different locations around the pyramid base to produce a tomographic image of the internal structures of the pyramid. The muon telescopes will use scintillator bars with embedded wavelength-shifting fibers read out by silicon photomultipliers, a technology successfully employed in several high-energy physics experiments. We will report on measurements made with a prototype detector at the Fermilab test beam facility and extensive simulation results showing the expected performance of the detectors. 

How to cite: Ehrlich, R.: Cosmic Ray Muon Imaging of the Great Pyramid of Giza, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8785, https://doi.org/10.5194/egusphere-egu23-8785, 2023.

Dry rock and soil have the capability to absorb and contain water because of their porosity. Measuring water concentration in different materials is important for many applications. For example, in heap leaching the leaching liquid distribution directly affects the metal recovery. The water concentration is the key parameter affecting the slope stability, and its measurement is therefore of a great importance for landslide prevention and tailing dams safety. Measurement of this parameter is however a significant challenge, and is done mostly by measuring rainfall in the field and/or analyzing soil samples in the laboratory. These measurements are model-dependent and require significant extrapolation of the results. 

A direct measurement of the water concentration in-situ is offered by muon radiography - through measuring density distribution based on cosmic-ray muon flux monitoring. By measuring the flux of muons from different directions we can reconstruct density maps of any object they traverse, including large volumes of rock. By monitoring the muon flux, our sensors are sensitive to the density changes in any material above it.  From these density changes we can infer the amount of water contained within the rock or soil.
         
We performed the first in-situ, fully volumetric monitoring of the water concentration in an active leaching heap in Chile.  Here we discuss the results of these pioneering measurements and the potential for muon imaging of the water concentration for different applications.

How to cite: Borozdin, K., Botto, T., De Beer, N., Repenning, R., and Rocha, C.: Measuring of water concentration in rock and soil with muon radiography, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13175, https://doi.org/10.5194/egusphere-egu23-13175, 2023.