arXiv subjects

Anzori Sh. Georgadze

Publications and source records attributed to Anzori Sh. Georgadze.

6 recordsLinked to original sources

arXiv2026

All-directional gamma-ray imaging using a NaI(Tl) scintillator with double-sided SiPM readout

Gamma-ray imaging systems capable of determining the direction of incident radiation are essential for homeland security, nuclear non-proliferation, environmental monitoring, and radiological emergency response. This work presents a compact, high-efficiency omnidirectional gamma-ray imaging concept based on a monolithic cylindrical 2 x 2 inch NaI(Tl) scintillation crystal coupled to dual-ended 16 x 16 Silicon Photomultiplier (SiPM) matrices. The system exploits scintillation light distributions collected from both crystal faces to reconstruct three-dimensional interaction positions. GEANT4 Monte Carlo simulations incorporating full optical photon transport were performed for 662 keV gamma rays from a ^137Cs source. The simulated energy resolution is 6.69% +- 0.31% FWHM at the photopeak. A hybrid directional reconstruction framework is implemented, combining volumetric self-attenuation (active masking) for robust low-energy localization with intra-crystal Compton imaging for higher energies. With approximately 40,000 accumulated photopeak counts, the active-masking algorithm achieves angular resolutions of FWHM_rm elev 5.7^degrees and FWHM_rm az 3.7^degrees. The system fully complies with the EN IEC 62327 standard for handheld radionuclide identification devices. Under the required 120-second acquisition window, it suppresses terrestrial background (NORM) from the lower hemisphere by a factor of ~320, improving to ~980 with 300-second integration. These results demonstrate that a monolithic dual-ended NaI(Tl) detector can transform a conventional scalar spectrometer into a sensitive, real-time directional imaging instrument suitable for portable field use and automated cargo inspection.

physics.ins-det↗

arXiv2025

The potential applications of muography to revealing sea shipwrecks

Muon imaging, a non-invasive technique that utilizes naturally occurring cosmic muons, has emerged as a promising tool for exploring underwater objects, including shipwrecks. This study investigates the potential of muon radiography to examine the contents of wrecked ships in the Baltic Sea and other marine environments. These wrecks often pose significant environmental risks due to hazardous contents such as explosives and crude oil, making their detection and monitoring critical for environmental and safety considerations. Accurate modeling and imaging of such wrecks are therefore essential for assessing potential dangers and mitigating environmental impacts. To model the underwater muon flux in this study, an approach similar to that used in underground muon experiments was adopted. Cosmic muons were propagated through seawater using GEANT4, modeling their energy loss as they traverse water. The muons' kinematics and energy depositions were recorded during this process. The resulting distributions were tabulated and used as input for the primary particle generation module. This method enabled the generation of a realistic underwater muon flux at the desired depth above the shipwreck, allowing us to simulate various shipwreck filling scenarios. Assuming an exposure time of one week for a wreck located at 50 meters depth, our simulations demonstrate that muon imaging can sufficiently resolve density contrasts to distinguish between water, oil, and high-density materials. These results demonstrate the feasibility of muon radiography as a practical tool for underwater hazard assessment and shipwreck investigation.

physics.ins-det↗

arXiv2025

Rapid muon tomography for border security

Cosmic-ray muon tomography is a promising technique for border security applications, leveraging highly penetrating cosmic-ray muons and their interactions with various materials to generate 3D images of large and dense objects, such as shipping containers. Using scattering and absorption of muons as they pass through dense cargo materials, muon tomography provides a viable solution for customs and border security by enabling the verification of shipping container declarations and preventing illegal trafficking. In this study, we utilized Monte Carlo simulations to evaluate the effectiveness of muon tomography for cargo characterization and contraband detection in various smuggling scenarios. Our results demonstrate that muon tomography can offers a novel approach to cargo inspection, moving beyond traditional 3D image reconstruction. Instead, it analyzes muon scattering and absorption rates in real time during scanning, enabling the prompt detection of discrepancies between actual cargo contents and declared goods within just 10 to 20 seconds. This method is particularly effective for cargo consisting of uniform loads composed of a single material or product, a common practice in shipping. Unlike traditional X-ray radiography, which analyzes detailed 2D images, muon tomography begins evaluating scatter-absorption rates within the first few seconds of scanning. This early assessment enables cargo evaluation long before a statistically reliable 3D image is formed, significantly improving scanning throughput without disrupting trade flow.

physics.app-ph↗

arXiv2025

Cherenkov detector with wavelength-shifting fiber readout for muon tomography applications

Cherenkov detectors have been extensively developed and utilized in various scientific fields, including particle physics, astrophysics, and nuclear engineering. These detectors operate based on Cherenkov radiation, which is emitted when a charged particle traverses a dielectric medium at a velocity greater than the phase velocity of light in that medium. In this work, we present the development of a Cherenkov radiation detector designed for a muon tomography system with high spatial resolution, employing wavelength-shifting (WLS) fiber readout. The detector consists of two large-area Cherenkov radiators, each measuring 1 m x 1 m, with each read out by WLS fibers arranged orthogonally to determine the x and y coordinates of muon hit positions. The system is modeled using the GEANT4 simulation package, and the achieved position resolution is is 1.8 mm+-0.1 (FWHM). The detector is inherently insensitive to natural background radiation and exhibits directional sensitivity, which helps prevent image blurring caused by muons scattered from the Earth's surface and entering the detector from the rear. This capability enables applications in non-invasive archaeological and geophysical imaging.

physics.ins-det↗

arXiv2025

Muon Imaging for Illicit Cargo Detection: A Simulation-Based Study

This study evaluates the potential of muon tomography as a non-invasive technique for detecting concealed illicit drugs in cargo, based on detailed simulations performed using the GEANT4 toolkit. A combined analysis of muon scattering and absorption data was employed to enhance material discrimination, with a focus on realistic smuggling scenarios involving cocaine hidden within legitimate cargo. A two-stage inspection protocol is proposed to balance detection speed and resolution. In the first stage, a rapid scan lasting ~ 60 seconds is used to identify anomalous scattering and absorption rates, without requiring full tomographic reconstruction. Receiver Operating Characteristic (ROC) analysis of rapid scan data revealed that the Random Forest classifier achieved an area under the curve (AUC) of 0.9969, while the multivariate normal likelihood model attained an AUC of 0.9977, both indicating excellent discrimination between benign cargo and smuggled contraband. Upon detection of anomalies, an extended scan ~30 minutes is initiated to enable high-resolution three-dimensional imaging for accurate localization and identification of hidden materials. Simulation results demonstrate that, with a detector spatial resolution of 1~mm (FWHM), concealed contraband such as cocaine can be detected with approximately 3 sigma statistical significance during the rapid scan phase. In extended scans, cocaine packages concealed within banana boxes were successfully visualized and automatically identified using clustering algorithms such as DBSCAN applied to the tomographic reconstruction. These findings confirm the feasibility of cosmic-ray muon tomography as a passive, safe, and effective approach for contraband detection in real-world cargo inspection applications.

physics.ins-det↗

arXiv2024

Rapid cargo verification with cosmic ray muon scattering and absorption tomography

Cosmic ray muon tomography is considered a promising method for the non-invasive inspection of shipping containers and trucks. It utilizes highly penetrating cosmic-ray muons and their interactions with various materials to generate three-dimensional images of large and dense, like inter-modal shipping containers, typically not transparent with conventional X-ray radiography technique. The commonly used methods for imaging with muons are based on muon scattering or absorption-transmission data analysis. Due to large thickness of cargo material in shipping container substantial scattering and absorption occur when muons passing through cargo. One of the key tasks of customs and border security is to verify shipping container declarations to prevent illegal trafficking, and muon tomography could be a viable choice for this task. In this paper, we demonstrate through Monte Carlo simulations using the GEANT4 toolkit that a combined analysis of muon scattering and absorption data can improve the identification of cargo materials compared to using scattering or absorption data alone. The statistical differences in scattering and absorption data for several cargo materials are quantified. For a particular smuggling scenario where tobacco declared as paper towel rolls, it is demonstrated that the combined analysis can accurately distinguish between tobacco and paper towel rolls with 5.5$σ$ accuracy for detector spatial resolution (FWHM) of 0.235 mm, 4.5$σ$ for 1.175 mm resolution (FWHM), and 3.9$σ$ accuracy for 2.35 mm spatial resolution (FWHM), in a short scanning time of 10 seconds. This rapid detection capability has significant implications for anti-smuggling efforts and cargo inspection.

physics.app-ph↗