Figure 1

Attenuation variation in the spectral dimension for a multi-phase powder phantom. (a) Set of four sinograms taken between channels 100-175 at equal spacing of 25 channels (corresponding average energies are shown-channel width 1.2 keV) for Scan A. A single discontinuity in the sinograms appears due to an interrupted scan. (b) The corresponding FDK reconstructions for each energy channel of the sinograms in (a). Three distinct regions are observed, corresponding to the three metal-based powders. The colour scale measures the attenuation, and is consistent across both images. Three ROIs are highlighted (white/blue squares, marked by numbers for each respective powder phase). (c) Average voxel spectra of powder phase ROI 1. A line signifying the theoretical position of the cerium K-edge is overlaid for comparison. (d) Comparison of measured absorption spectra (top) for ROIs 2 and 3 located in the zinc oxide and iron phases respectively, and the theoretical values (bottom) over the same spectral range.