Robust [Formula: see text]-mapping in composites via joint beam-hardening and detector-response correction

Area of Science:

• Medical Physics
• Materials Science
• Imaging Science

Background:

• Quantitative effective atomic number (Zeff) imaging is crucial but hindered by beam hardening and detector response.
• Spectral distortion in X-ray projection imaging affects accuracy.

Purpose of the Study:

• To develop a joint beam-hardening and detector-response correction framework for thickness-decoupled Zeff inversion.
• To improve the accuracy and stability of Zeff calculations in X-ray imaging.

Main Methods:

• A folded-spectrum forward model incorporating X-ray spectrum, attenuation, and detector response was established.
• Monte Carlo simulations were used to create a response-corrected spectral database.
• Spectral mass-attenuation linearization and reliability-weighted least-squares spectral matching were employed for Zeff inversion.

Main Results:

• Experimental validation showed improved thickness stability and quantitative agreement for standard materials.
• The method was successfully applied to carbon-fiber-reinforced polymer specimens with inclusions.
• Resulting Zeff maps provided material-dependent contrast, aiding discrimination.

Conclusions:

• The proposed framework effectively corrects spectral distortions in X-ray imaging.
• This approach enhances quantitative Zeff inversion and material characterization.
• The method shows potential for qualitative and semi-quantitative material discrimination in composite non-destructive testing.