Uranium-sensitive tomography with synchrotron radiation

Element-sensitive tomography produces quality information in the field of medical imaging. This method, also known as dichromatic tomography, can be useful to visualize the distribution of heavy elements, such as actinides, without destroying the sample. One of the problems is to obtain a monochromatic photon beam of sufficiently high energy; the other is to have a way of recording these high-energy photons with a good spatial resolution. Here, the results of a first experiment on uranium mapping with synchrotron radiation are reported. Various natural and artificial samples of a few centimetres in size with uranium concentration between 0.008 g cm^-3 and 2 g cm^-3 were scanned using photon beams around 115 keV and a specially designed camera. The data were then analysed using a conventional fast reconstruction technique. This yielded excellent results with spatial resolutions down to 50 µm. For the first time it was shown that element-sensitive tomography using synchrotron radiation could be extended to the heaviest natural element. Therefore, in principle, the spatial distribution of any element can now be reconstructed using synchrotron radiation. Extension of this technique to very heavy elements can be important for geology, health physics and nuclear waste storage.