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1
Machnio, Piotr, Michał Ziemczonok, and Małgorzata Kujawińska. "Reconstruction enhancement via projection screening in holographic tomography." Photonics Letters of Poland 13, no. 2 (June 30, 2021): 37. http://dx.doi.org/10.4302/plp.v13i2.1104.
Анотація:
This paper presents an algorithm for automatic detection of erroneous amplitude and phase components of a sample’s optical field, acquired by a holographic tomograph with a limited angle of projection. By applying image processing methods and statistical analysis to find and remove unfit projections, the quality of tomographic reconstruction of a 3D refractive index distribution of an object is greatly improved. The proposed methods can find their application in preprocessing of data in holographic tomography. Full Text: PDF ReferencesA. Kuś, W. Krauze, P. L. Makowski, and M. Kujawińska, "Holographic tomography: hardware and software solutions for 3D quantitative biomedical imaging (Invited paper)", ETRI Journal, 41, 1 (2019). CrossRef V. Balasubramani et al., "Phase unwrapping in ICF target interferometric measurement via deep learning", Appl. Opt., 60, 10 (2021). CrossRef Y. Park, C. Depeursinge, and G. Popescu, "Quantitative phase imaging in biomedicine", Nature Photonics, 12, 10 (2018). CrossRef W. Krauze, P. Makowski, M. Kujawińska, and A. Kuś, "Generalized total variation iterative constraint strategy in limited angle optical diffraction tomography", Opt. Express, 24, 5 (2016). CrossRef D. Ryu et al., "A non-calorimetric approach for investigating the moisture-induced ageing of a pyrotechnic delay material using spectroscopies", Sci Rep, 9, 1 (2019). CrossRef B. S. Lipkin, Picture Processing and Psychopictorics. (Saint Louis, Elsevier Science 2014). DirectLink A. M. Taddese, N. Verrier, M. Debailleul, J.-B. Courbot, and O. Haeberlé, "Optimizing sample illumination scanning in transmission tomographic diffractive microscopy", Appl. Opt., 60, 6 (2021). CrossRef
2
Krauze, Wojciech, Piotr Makowski, Małgorzata Kujawińska, and Arkadiusz Kuś. "Generalized total variation iterative constraint strategy in limited angle optical diffraction tomography." Optics Express 24, no. 5 (February 26, 2016): 4924. http://dx.doi.org/10.1364/oe.24.004924.
3
Costa, Jessé C., Francisco J. da Silva, Ellen N. Gomes, Jörg Schleicher, Luiz André Melo, and Daniela Amazonas. "Regularization in slope tomography." GEOPHYSICS 73, no. 5 (September 2008): VE39—VE47. http://dx.doi.org/10.1190/1.2967499.
Анотація:
Seismic imaging in depth is limited by the accuracy of velocity model estimation. Slope tomography uses the slowness components and traveltimes of picked reflection or diffraction events for velocity model building. The unavoidable data incompleteness requires additional information to assure stability to inversion. One natural constraint for ray-based tomography is a smooth velocity model. We propose a new, reflection-angle-based kind of smoothness constraint as regularization in slope tomography and have compared its effects to three other, more conventional constraints. The effects of these constraints were evaluated through angle-domain common-image gathers, computed with wave-equation migration using the estimated velocity model. We found that the smoothness constraints have a distinct effect on the velocity model but a weaker effect on the migrated data. In numerical tests on synthetic data, the new constraint leads to geologically more consistent models.
4
Dickens, Thomas A. "Diffraction tomography for crosswell imaging of nearly layered media." GEOPHYSICS 59, no. 5 (May 1994): 694–706. http://dx.doi.org/10.1190/1.1443627.
Анотація:
Diffraction tomography is a high‐resolution imaging technique applicable to the mapping of formation velocities away from the borehole, achieving a spatial resolution of better than one acoustic wavelength when used to image synthetic model data. However, traditional filtered back‐propagation diffraction tomography algorithms are based on weak‐scattering and constant‐background velocity assumptions, which limits their applicability to models of realistic structural complexity. Results are obtained using a new, computationally efficient single‐mode (P‐wave) diffraction tomography algorithm that is applicable to models, including geologically realistic ones, whose strongest variations can be approximated as a set of horizontal layers. The algorithm starts with a layered model of the subsurface velocity structure, which may be constructed from well logs or by using traveltime tomography. Application of layered diffraction tomography updates this model to reveal 2-D structures such as faults, pinch‐outs, and dips. An overview of the layered diffraction tomography algorithm and information on its computational implementation are presented. Layered diffraction tomography can, given an accurate initial model, successfully image complex structures for which filtered back‐propagation fails, with a spatial resolution on the order of one‐third wavelength. Synthetic crosswell data are used to construct images of models ranging from an isolated simple target to geologically realistic structures containing faults, erosional surfaces, and dipping beds. The initial layered model must represent the actual subsurface structure with as much fidelity as possible; it is important to use all available a priori information in the construction of this model. The enhanced spatial resolution provided by diffraction tomography does not require the use of high‐angle reflections; in the presence of noise, image quality and resolution can be largely maintained by using only a short time window of (the high S/N) data immediately following the first break that is employed for traveltime imaging.
5
Rekdal, Thorbjørn, and Durk J. Doornbos. "A modified form of diffraction tomography to image boundary structures." GEOPHYSICS 58, no. 8 (August 1993): 1136–47. http://dx.doi.org/10.1190/1.1443497.
Анотація:
Wavefield extrapolation downward from the surface, as applied in migration and associated inversion methods, is a common procedure to image subsurface reflectors. These methods require adequate (i.e., extensive and unaliased) sampling of the surface wavefield. Seismic tomography on the other hand, relates parameters of the upward propagated wavefield to the diffracting image, and sampling requirements are less severe; it is usually the only option to image deep structures from sparse data. The ordinary form of ray tomography, however, imposes a severe smoothness constraint on the boundary; in particular the “tops” and “valleys” of a relatively rough structure are not well‐resolved. We have implemented a generalized form of tomography, which uses both the ray term and the diffraction term linearized in the boundary perturbation. We introduce a generalized reflection coefficient that can be linearized in terms of the (unknown) boundary gradient, and we demonstrate the adequacy of this approximation with the help of synthetic seismograms. We compare the performance of the new inversion method with migration and ray tomography in a number of model experiments where a source and receiver array are used to image (1) a rough sea bottom and (2) a rough sedimentary layer boundary. In these experiments the new method is superior, especially in the outer part of the inversion region where migration and seismic tomography suffer seriously because of the lack of adequate surface information. Even for well‐controlled surveys there is the potential to successfully image a much larger area of the reflector than is possible with migration. Our experiments involved a single reflector in a known velocity‐density structure. The method’s applicability or modifications required when relaxing these assumptions, remains to be investigated.
6
Liang, Kaichao, Li Zhang, and Yuxiang Xing. "Reciprocal-FDK reconstruction for x-ray diffraction computed tomography." Physics in Medicine & Biology 67, no. 9 (April 20, 2022): 095009. http://dx.doi.org/10.1088/1361-6560/ac5bf9.
Анотація:
Abstract Objective. X-ray diffraction (XRD) technology uses x-ray small-angle scattering signal for material analysis, which is highly sensitive to material inter-molecular structure. To meet the high spatial resolution requirement in applications such as medical imaging, XRD computed tomography (XRDCT) has been proposed to provide XRD intensity with improved spatial resolution from point-wise XRD scan. In XRDCT, 2D spatial tomography corresponds to a 3D reconstruction problem with the third dimension being the XRD spectrum dimension, i.e. the momentum transfer dimension. Current works in the field have studied reconstruction methods for either angular-dispersive XRDCT or energy-dispersive XRDCT for small samples. The approximations used are only suitable for regions near the XRDCT iso-center. A new XRDCT reconstruction method is needed for more general imaging applications. Approach. We derive a new FDK-type reconstruction method (Reciprocal-FDK) for XRDCT without limitation on object size. By introducing a set of reciprocal variables, the XRDCT model is transformed into a classical cone-parallel CT model, which is an extension of a circular-trajectory cone-beam CT model, after which the FDK method is applied for XRDCT reconstruction. Main results. Both analytical simulation and Monte Carlo simulation experiments are conducted to validate the XRDCT reconstruction method. The results show that when compared to existing analytical reconstruction methods, there are improvements in the proposed Reciprocal-FDK method with regard to relative structure reconstruction and XRD pattern peak reconstruction. Since cone-parallel CT does not satisfy the data completeness condition, cone-angle effect affects the reconstruction accuracy of XRDCT. The property of cone-angle effect in XRDCT is also analyzed with ablation studies. Significance. We propose a general analytical reconstruction method for XRDCT without constraint on object size. Reciprocal-FDK provides a complete derivation and theoretical support for XRDCT reconstruction by analogy to the well-studied cone-parallel CT model. In addition, the intrinsic problem with the XRDCT data model and the corresponding reconstruction error are discussed for the first time.
7
Fang, Haixing, Wolfgang Ludwig, and Pierre Lhuissier. "Implementation of grain mapping by diffraction contrast tomography on a conventional laboratory tomography setup with various detectors." Journal of Applied Crystallography 56, no. 3 (May 31, 2023): 810–24. http://dx.doi.org/10.1107/s1600576723003874.
Анотація:
Laboratory-based diffraction contrast tomography (LabDCT) is a novel technique used to resolve grain orientations and shapes in three dimensions at the micrometre scale using laboratory X-ray sources, allowing the user to overcome the constraint of limited access to synchrotron facilities. To foster the development of this technique, the implementation of LabDCT is illustrated in detail using a conventional laboratory-based X-ray tomography setup, and it is shown that such implementation is possible with the two most common types of detectors: CCD and flat panel. As a benchmark, LabDCT projections were acquired on an AlCu alloy sample using the two types of detectors at different exposure times. Grain maps were subsequently reconstructed using the open-source grain reconstruction method reported in the authors' previous work. To characterize the detection limit and the spatial resolution for the current implementation, the reconstructed LabDCT grain maps were compared with the map obtained from a synchrotron measurement, which is considered as ground truth. The results show that the final grain maps from measurements by the CCD and flat panel detector are similar and show comparable quality, while the CCD gives a much better contrast-to-noise ratio than the flat panel. The analysis of the grain maps reconstructed from measurements with different exposure times suggests that a grain map of comparable quality could be obtained in less than 1 h total acquisition time without a significant loss of grain reconstruction quality and indicates a clear potential for time-lapse LabDCT experiments. The current implementation is suggested to promote the generic use of the LabDCT technique for grain mapping on conventional tomography setups.
8
Atakul-Özdemir, Ayse, Xander Warren, Peter G. Martin, Manuel Guizar-Sicairos, Mirko Holler, Federica Marone, Carlos Martínez-Pérez, and Philip C. J. Donoghue. "X-ray nanotomography and electron backscatter diffraction demonstrate the crystalline, heterogeneous and impermeable nature of conodont white matter." Royal Society Open Science 8, no. 8 (August 2021): 202013. http://dx.doi.org/10.1098/rsos.202013.
Анотація:
Conodont elements, microfossil remains of extinct primitive vertebrates, are commonly exploited as mineral archives of ocean chemistry, yielding fundamental insights into the palaeotemperature and chemical composition of past oceans. Geochemical assays have been traditionally focused on the so-called lamellar and white matter crown tissues; however, the porosity and crystallographic nature of the white matter and its inferred permeability are disputed, raising concerns over its suitability as a geochemical archive. Here, we constrain the characteristics of this tissue and address conflicting interpretations using ptychographic X-ray-computed tomography (PXCT), pore network analysis, synchrotron radiation X-ray tomographic microscopy (srXTM) and electron back-scatter diffraction (EBSD). PXCT and pore network analyses based on these data reveal that while white matter is extremely porous, the pores are unconnected, rendering this tissue closed to postmortem fluid percolation. EBSD analyses demonstrate that white matter is crystalline and comprised of a single crystal typically tens of micrometres in dimensions. Combined with evidence that conodont elements grow episodically, these data suggest that white matter, which comprises the denticles of conodont elements, grows syntactically, indicating that individual crystals are time heterogeneous. Together these data provide support for the interpretation of conodont white matter as a closed geochemical system and, therefore, its utility of the conodont fossil record as a historical archive of Palaeozoic and Early Mesozoic ocean chemistry.
9
Perotti, Giulia, Henning O. Sørensen, Henning Haack, Anja C. Andersen, Dario Ferreira Sanchez, Elishevah M. M. E. van Kooten, Esther H. R. Tsai, et al. "Thermal History of Matrix Forsterite Grains from Murchison Based on High-resolution Tomography." Astrophysical Journal 922, no. 2 (December 1, 2021): 256. http://dx.doi.org/10.3847/1538-4357/ac26bc.
Анотація:
Abstract Protoplanetary disks are dust- and gas-rich structures surrounding protostars. Depending on the distance from the protostar, this dust is thermally processed to different degrees and accreted to form bodies of varying chemical compositions. The primordial accretion processes occurring in the early protoplanetary disk such as chondrule formation and metal segregation are not well understood. One way to constrain them is to study the morphology and composition of forsteritic grains from the matrix of carbonaceous chondrites. Here, we present high-resolution ptychographic X-ray nanotomography and multimodal chemical microtomography (X-ray diffraction and X-ray fluorescence) to reveal the early history of forsteritic grains extracted from the matrix of the Murchison CM2.5 chondrite. The 3D electron density maps revealed, at unprecedented resolution (64 nm), spherical inclusions containing Fe–Ni, very little silica-rich glass and void caps (i.e., volumes where the electron density is consistent with conditions close to vacuum) trapped in forsterite. The presence of the voids along with the overall composition, petrological textures, and shrinkage calculations is consistent with the grains experiencing one or more heating events with peak temperatures close to the melting point of forsterite (∼2100 K), and subsequently cooled and contracted, in agreement with chondrule-forming conditions.
10
Albert, J. G., M. S. S. L. Oei, R. J. van Weeren, H. T. Intema, and H. J. A. Röttgering. "A probabilistic approach to direction-dependent ionospheric calibration." Astronomy & Astrophysics 633 (January 2020): A77. http://dx.doi.org/10.1051/0004-6361/201935668.
Анотація:
Calibrating for direction-dependent ionospheric distortions in visibility data is one of the main technical challenges that must be overcome to advance low-frequency radio astronomy. In this paper, we propose a novel probabilistic, tomographic approach that utilises Gaussian processes to calibrate direction-dependent ionospheric phase distortions in low-frequency interferometric data. We suggest that the ionospheric free electron density can be modelled to good approximation by a Gaussian process restricted to a thick single layer, and show that under this assumption the differential total electron content must also be a Gaussian process. We perform a comparison with a number of other widely successful Gaussian processes on simulated differential total electron contents over a wide range of experimental conditions, and find that, in all experimental conditions, our model is better able to represent observed data and generalise to unseen data. The mean equivalent source shift imposed by our predictive errors are half as large as those of the best competitor model. We find that it is possible to partially constrain the hyperparameters of the ionosphere from sparse-and-noisy observed data. Our model provides an alternative explanation for observed phase structure functions deviating from Kolmogorov’s five-thirds turbulence, turnover at high baselines, and diffractive scale anisotropy. We show that our model performs tomography of the free electron density both implicitly and cheaply. Moreover, we find that even a fast, low-resolution approximation of our model yields better results than the best alternative Gaussian process, implying that the geometric coupling between directions and antennae is a powerful prior that should not be ignored.
11
Zhai, Chongpu, Eric B. Herbold, and Ryan C. Hurley. "The influence of packing structure and interparticle forces on ultrasound transmission in granular media." Proceedings of the National Academy of Sciences 117, no. 28 (June 29, 2020): 16234–42. http://dx.doi.org/10.1073/pnas.2004356117.
Анотація:
Ultrasound propagation through externally stressed, disordered granular materials was experimentally and numerically investigated. Experiments employed piezoelectric transducers to excite and detect longitudinal ultrasound waves of various frequencies traveling through randomly packed sapphire spheres subjected to uniaxial compression. The experiments featured in situ X-ray tomography and diffraction measurements of contact fabric, particle kinematics, average per-particle stress tensors, and interparticle forces. The experimentally measured packing configuration and inferred interparticle forces at different sample stresses were used to construct spring networks characterized by Hessian and damping matrices. The ultrasound responses of these network were simulated to investigate the origins of wave velocity, acoustic paths, dispersion, and attenuation. Results revealed that both packing structure and interparticle force heterogeneity played an important role in controlling wave velocity and dispersion, while packing structure alone quantitatively explained most of the observed wave attenuation. This research provides insight into time- and frequency-domain features of wave propagation in randomly packed granular materials, shedding light on the fundamental mechanisms controlling wave velocities, dispersion, and attenuation in such systems.
12
Wang, Qianqian, Shize Liu, Xuejun Gao, Yan Wei, Xuliang Deng, Haifeng Chen, and Xuehui Zhang. "Remineralizing Efficacy of Fluorohydroxyapatite Gel on Artificial Dentinal Caries Lesion." Journal of Nanomaterials 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/380326.
Анотація:
The aim was to evaluate the remineralizing efficacy of fluorohydroxyapatite (FHA) gel on artificial dentinal caries lesion in vitro. Artificial carious lesions were made on occlusal cavities of teeth by exposing the dentin surface to a demineralizing solution. Each cavity was capped with a 3 mm thick FHA gel for 4 weeks. After the FHA gel was removed, the surface morphology and structure of the dentin were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The dentin mineral density (DMD) was measured by micro-computed tomography (Micro-CT). A layer of dense and orderly hexagonal crystal structure, with average diameter of 1 μm and thickness of 4~5 μm, could be observed on dentin surface. These crystals exhibited elemental peaks for calcium, phosphorus, carbon, and oxygen and characteristic peaks of hydroxyapatite (HA) and fluorapatite (FA) via XRD and FT-IR. The DMD of dentin surface layer significantly increased after it was capped with FHA gel (P<0.05). In the present study, the FHA gel could rapidly construct apatite on the artificial dentin caries surface and significantly increase the mineral density, which suggests that FHA gel might be a proper IPT material with remineralizing function.
13
Du, Meng, Zhengming Yang, Shuo Yang, Chun Feng, Guofeng Wang, Ninghong Jia, Haibo Li, and Xiaoxing Shi. "Study on the Quantitative Characterization and Heterogeneity of Pore Structure in Deep Ultra-High Pressure Tight Glutenite Reservoirs." Minerals 13, no. 5 (April 26, 2023): 601. http://dx.doi.org/10.3390/min13050601.
Анотація:
The precise characterization of a tight glutenite reservoir’s microscopic pore structure is essential for its efficient development. However, it is difficult to accurately evaluate using a single method, and its microscopic heterogeneity is not fully understood. In this study, a combination of X-ray diffraction, casting thin section observations, scanning electron microscopy, high-pressure mercury injection, constant-speed mercury injection, X-ray computed tomography, and the advanced mathematical algorithms in the AVIZO 8.0 visualization software was used to construct the three-dimensional digital core of a glutenite reservoir at the study site, and the parameters of the pore network model were extracted. The overall microscopic pore structure characteristics were quantitatively investigated from multiple scales. Based on this, the mineral quantitative evaluation system (QEMSCAN) examined the microscopic heterogeneity of the glutenite reservoir and its impact on seepage. The results show that the glutenite reservoir in the study block can be classified into three categories based on lithology and capillary pressure curve characteristics. The type I reservoir samples have large and wide pore throats, low threshold pressure, and high reservoir quality; type II reservoir samples are characterized by medium-sized pore throat, medium threshold pressure, and moderate reservoir quality; and the small and narrow pore throat, high threshold pressure, and poor reservoir quality are characteristics of type III reservoir samples. The various pore throat types and mineral distributions are due to the differences in dissolution, compaction, and cementation. The continuous sheet pores have good connectivity, which is related to the interconnection of primary intergranular pores and strip fractures, while the connectivity of isolated pores is significantly poor, which is related to the development of intragranular dissolved pores and intercrystalline pores. This suggests the deterioration of physical properties and pore throat connectivity, reduced average pore radius, and decreased pore sorting as decreasing permeability. The tight glutenite pores range in size from 5 nm to 80 μm and primarily feature Gaussian and bimodal distribution patterns, and submicron–micron pores contribute more to seepage. The effective pores were found to be attributed to the slowing effect of abnormally high pressure on the vertical stress, and the protective effect was positively correlated with the high-pressure strength. Notably, there is strong microscopic heterogeneity in the distribution of the reservoir matrix minerals and the pore throat size. As a result, the injected fluid easily flows along the preferential seepage channel with pore development and connectivity. This study provides new insights into the exploration and development of similar tight reservoirs.
14
Wang, Qianke, Jun Liu, Dawei Lyu, and Jian Wang. "Ultrahigh-fidelity spatial mode quantum gates in high-dimensional space by diffractive deep neural networks." Light: Science & Applications 13, no. 1 (January 5, 2024). http://dx.doi.org/10.1038/s41377-023-01336-7.
Анотація:
AbstractWhile the spatial mode of photons is widely used in quantum cryptography, its potential for quantum computation remains largely unexplored. Here, we showcase the use of the multi-dimensional spatial mode of photons to construct a series of high-dimensional quantum gates, achieved through the use of diffractive deep neural networks (D2NNs). Notably, our gates demonstrate high fidelity of up to 99.6(2)%, as characterized by quantum process tomography. Our experimental implementation of these gates involves a programmable array of phase layers in a compact and scalable device, capable of performing complex operations or even quantum circuits. We also demonstrate the efficacy of the D2NN gates by successfully implementing the Deutsch algorithm and propose an intelligent deployment protocol that involves self-configuration and self-optimization. Moreover, we conduct a comparative analysis of the D2NN gate’s performance to the wave-front matching approach. Overall, our work opens a door for designing specific quantum gates using deep learning, with the potential for reliable execution of quantum computation.
15
Jourdan, Fred, Nicholas E. Timms, Tomoki Nakamura, William D. A. Rickard, Celia Mayers, Steven M. Reddy, David Saxey, et al. "Rubble pile asteroids are forever." Proceedings of the National Academy of Sciences 120, no. 5 (January 23, 2023). http://dx.doi.org/10.1073/pnas.2214353120.
Анотація:
Rubble piles asteroids consist of reassembled fragments from shattered monolithic asteroids and are much more abundant than previously thought in the solar system. Although monolithic asteroids that are a kilometer in diameter have been predicted to have a lifespan of few 100 million years, it is currently not known how durable rubble pile asteroids are. Here, we show that rubble pile asteroids can survive ambient solar system bombardment processes for extremely long periods and potentially 10 times longer than their monolith counterparts. We studied three regolith dust particles recovered by the Hayabusa space probe from the rubble pile asteroid 25143 Itokawa using electron backscatter diffraction, time-of-flight secondary ion mass spectrometry, atom probe tomography, and 40 Ar/ 39 Ar dating techniques. Our results show that the particles have only been affected by shock pressure of ca. 5 to 15 GPa. Two particles have 40 Ar/ 39 Ar ages of 4,219 ± 35 and 4,149 ± 41 My and when combined with thermal and diffusion models; these results constrain the formation age of the rubble pile structure to ≥4.2 billion years ago. Such a long survival time for an asteroid is attributed to the shock-absorbent nature of rubble pile material and suggests that rubble piles are hard to destroy once they are created. Our results suggest that rubble piles are probably more abundant in the asteroid belt than previously thought and provide constrain to help develop mitigation strategies to prevent asteroid collisions with Earth.
16
Lauper, Bruno, Géraldine N. Zimmerli, David Jaeggi, Gaudenz Deplazes, Stephan Wohlwend, Johannes Rempfer, and Anneleen Foubert. "Quantification of Lithological Heterogeneity Within Opalinus Clay: Toward a Uniform Subfacies Classification Scheme Using a Novel Automated Core Image Recognition Tool." Frontiers in Earth Science 9 (May 12, 2021). http://dx.doi.org/10.3389/feart.2021.645596.
Анотація:
The Opalinus Clay is notable in Switzerland as being the selected host rock for deep geological disposal of radioactive waste. Since the early 1990’s, this argillaceous mudstone formation of Jurassic age has been intensively studied within the framework of national and international projects to characterize its geological, hydrological, mechanical, thermal, chemical, and biological properties. While there is no formal stratigraphic subdivision, the Opalinus Clay lithology is classically divided into several, dam- to m-scale sub-units (or facies), depending on location. Recent multi-proxy studies (combining petrographic, petrophysical, geochemical, and mineralogical analyses) have however demonstrated that high, intra-facies, lithological heterogeneity occurs at the dm- to cm-scale. To constrain this small-scale heterogeneity into distinct lithological units (subfacies), the present study aims at defining and presenting a convenient subfacies classification scheme covering the overall Opalinus Clay lithology across northern Switzerland. Petrographic (macro- and microfacies), mineralogical (X-ray diffraction) and textural (image analysis, machine learning and 3D X-ray computed tomography) analyses are performed on diverse drill cores from the Mont Terri rock laboratory (northwestern Switzerland), and results are extended further to the east (Riniken, Weiach, and Benken). Most of the investigated Opalinus Clay can be described by the use of five distinctive subfacies types (SF1 to SF5), which are visually and quantitatively distinguishable by texture (grain size, bedding, fabric, and color) and composition (nature and mineralogy of components). The five subfacies types can be further refined by additional attributes and sedimentary characteristics (biogenic, diagenetic, and structural). Eventually, the widespread and consistent use of standardized Opalinus Clay subfacies types provides the means to harmonize petrographic descriptions within multidisciplinary research projects, enhance reproducibility of in situ experiments, and further evidence the tight relations between lithology and various rock properties.