A method for aligning a radiographic inspection system includes providing a radiation source capable of emitting a beam pattern, positioning a detector to receive radiation emitted from the radiation source, and causing the radiation source to emit the beam pattern. The detector is used to determine the distribution of flux intensity of the beam pattern. A two-dimensional or three-dimensional map of the beam pattern may be stored. The system is aligned by positioning the radiation source and the detector with reference to the map, so that the detector is disposed at a predetermined location within the beam pattern.