to deviation between the assumptions of the model and artificial image generator. Tomo-NeRF and artificial image generators assume a monochromatic beam. In reality, synchrotron facilities produce monochromatic beams (I 0 ) through single-crystal monochromators and Xray diffraction at a higher intensity than the in-house imaging facility in our experiment. The in-house imaging facility uses the filter to decrease the intensity of the beams with an unwanted wavelength, yet the emitted radiation is still polychromatic, which is different from the ideal assumption (Eq. 2). This deviations results in an attenuation coefficient which is dependent on the local spatial heterogenity in the sample and X-ray energy (i.e., µ(x, y, z; ε)). In addition, the lower energy of the in-house facility increases the contrast I d /I 0 (e.g., the overexposure for the void region near the overlapping particles), and results in more noise in the real experiment (Figure ). By comparing the input images from the real sample (Figure ) and that from the artificial samples (Figure ), we can see that there is information loss in the particle shape, where the boundaries of the overlapping particles cannot be resolved due to high contrast and noise. It is more difficult for the convolution network to extract features from blurrier input radiographic images, leading to higher deviations of localized porosity in the central region (Figure ).