Calculation of effective atomic numbers using a rational polynomial approximation method with a dual-energy X-ray...

Area of Science:

• Medical Physics
• Imaging Science
• Materials Science

Background:

• Accurate effective atomic number (Zeff) calculation is crucial for material identification in dual-energy X-ray imaging.
• Conventional polynomial approximation methods have limitations in Zeff calculation accuracy.
• Optimizing Zeff calculation improves the performance of X-ray imaging systems.

Purpose of the Study:

• To develop a novel rational polynomial approximation method for enhanced Zeff calculation accuracy.
• To validate the proposed method using simulated and experimental data.
• To assess the method's applicability in baggage inspection for explosives detection.

Main Methods:

• A multi-materials calibration model with iterative optimization was employed.
• A rational polynomial approximation was introduced to improve Zeff calculation.
• Twelve reference materials (Zeff 5.444–22) were used for model calibration.
• Simulated and experimental studies validated the method's performance.

Main Results:

• The rational polynomial approximation method improved Zeff calculation accuracy by approximately 40% compared to conventional methods.
• Relative differences between calculated and experimental Zeff values were below 8.5% for all samples.
• The method demonstrated compliance with international baggage inspection standards for explosives detection.
• Dual-energy images showed significant contrast for explosives using the proposed method.

Conclusions:

• The proposed rational polynomial approximation method offers a significant improvement in Zeff calculation accuracy for dual-energy X-ray imaging.
• This method enhances material characterization and is suitable for security applications like explosives detection.
• The technique provides a computationally efficient way to improve imaging system performance.