Figure 1.

The sample is translated along an axis which is perpendicular to the beam axis while being illuminated with an X-ray beam and rotated, typically covering an angular range of 0 to π, while two-dimensional diffraction patterns (size X × Y) are recorded with an area detector. The total number of two-dimensional diffraction patterns collected is equal to T × R, where T is the number of translation steps and R is the number of rotation steps. The two-dimensional diffraction patterns are then azimuthally integrated to give one-dimensional diffraction patterns (containing d observation points) which are plotted as a function of translations and rotations, yielding the sinogram volume (T × R × d matrix). The reconstructed volume (T × T × d matrix) is derived by applying a tomographic reconstruction algorithm to the sinogram volume. The images shown in this figure were derived from the XRD-CT data presented later in this paper.