Optimizing contrast agents with respect to reducing beam hardening in nonmedical X-ray computed tomography experiments.
X-ray computed tomography (CT) images obtained with a polychromatic X-ray source were simulated by computer for homogeneous solutions and suspensions containing a heavy element. When the K-edge of the element was near the peak energy of the polychromatic X-ray spectrum, the degree of beam hardening in the simulated CT image strongly depended on the atomic number and molar concentration of the heavy element. We analyzed the beam hardening of a single measured CT image of a CeCl(3) aqueous solution sample, and successfully estimated the atomic number and the molar concentration of Ce simultaneously within a certain error. This single-shot, or single-energy (as opposed to dual-energy), CT method permits quick, nondestructive screening of a hazardous heavy element in a solution or suspension confined in a container.