Materials analysis using x-ray linear attenuation coefficient measurements at four photon energies

Area of Science:

• Medical Physics
• Materials Science
• Computational Physics

Background:

• Accurate measurement of x-ray linear attenuation coefficients is crucial for materials analysis.
• Existing parameterization schemes may lack accuracy or applicability in specific energy ranges.
• Diagnostic x-ray energies (20-150 keV) present unique challenges for accurate attenuation analysis.

Purpose of the Study:

• To examine the analytical properties of a novel parameterization scheme for x-ray linear attenuation coefficients.
• To develop and validate a method for materials analysis using this parameterization within the diagnostic energy range.
• To address mathematical challenges in solving the inverse problem for in vivo applications.

Main Methods:

• Developed an additive parameterization using compositional- and energy-dependent coefficients.
• Utilized elemental cross-section parameterization and mixture parameters (electron density, statistical moments).
• Employed an iterative inversion strategy for materials analysis with multi-energy measurements.

Main Results:

• The parameterization accurately models x-ray linear attenuation coefficients.
• Electron density was recovered to within +/-4% using diagnostic x-ray energies.
• The second and third mixture parameters were found to be unrecoverable due to minor importance at these energies.

Conclusions:

• The proposed parameterization scheme is effective for materials analysis using diagnostic x-ray energies.
• An iterative inversion strategy successfully overcomes mathematical pathologies in this energy regime.
• The method allows for reliable determination of electron density, crucial for various applications.