Impact of object positioning and Compton scattering on material discrimination in high-energy X-ray cargo scans

• Published in: Radiation physics and chemistry (Oxford, England : 1993) England : 1993), 2025-04, Vol.229, p.112444, Article 112444
• Main Authors: Barati, Hossein, Feghhi, Seyed AmirHossein, Azimirad, Rouhollah
• Format: Article
• Language: English
• Subjects: Curve-based material discrimination; Dual-energy; Focused angular distribution; Improving image quality; Radiography
• ISSN: 0969-806X
• DOI: 10.1016/j.radphyschem.2024.112444

A key challenge in multi-energy X-ray inspection systems is the effect of object positioning on material discrimination accuracy. This study addresses the issue by conducting experiments with various materials placed at different positions. Four wedge-shaped samples were tested at different heights and angles within a standard dual-energy cargo inspection system. The results demonstrated that object positioning significantly influences the distribution of radiation reaching the detectors, mainly due to variations in the amount of Compton-scattered X-rays. These changes notably affect material discrimination curves. Additionally, placing objects farther from the accelerator enhanced material discrimination accuracy by 4-14% and improved detection precision by 4%–14% for some detectors. The findings highlight the need for precise control over experimental conditions to achieve optimal material discrimination results. The insights gained from this study can contribute to optimizing multi-energy X-ray inspection systems, improving material discrimination capabilities, and enhancing precision in threat detection. •Object positioning significantly impacts the distribution of X-rays reaching the detector in dual-energy X-ray cargo scanning.•Material discrimination curves are demonstrably affected by object positioning.•A direct correlation exists between material discrimination accuracy and the distance of objects from the accelerator.•Placing samples closer to the detector minimizes the standard deviation in the data, leading to a more precise definition of material boundaries and consequently, enhanced discrimination accuracy.•The investigation highlights the critical role of object positioning and the impact of Compton scattering distribution on material discrimination in dual-energy X-ray scanning.