A new method enables precise mapping of the effective atomic number (Z_eff) in composite materials, overcoming limitations of current techniques. This advance is crucial for applications in materials science, security, and medicine, where elemental composition is key. The method addresses two significant challenges in X-ray tomography: beam hardening and detector response, which distort attenuation measurements.

Beam hardening occurs when low-energy X-rays are preferentially absorbed, altering the beam's spectrum as it passes through the material. Detector response, on the other hand, refers to how the detector converts X-ray photons into a measurable signal, which can introduce nonlinearities and artifacts. By jointly correcting these effects, the new approach significantly improves the fidelity of Z_eff mapping in heterogeneous materials, where compositional variations are common.

The developed technique provides a more reliable distribution of Z_eff, a parameter that reflects the average elemental composition of a material. This is particularly relevant in composite materials with multiple phases and elements, where macroscopic properties critically depend on microstructure and Z_eff distribution. The ability to robustly map Z_eff opens new avenues for non-destructive characterization and quality control across various industries.