A TUNABLE MONOCHROMATIC GAMMA-RAY SOURCE .3. FEASIBILITY STUDY OF HEAVY ELEMENT TOMOGRAPHY

When the energy of a monochromatic gamma-ray beam is tuned over the K- edge of an element, the absorption of the beam due to this element cha nges abruptly. Using the tunable monochromatic gamma-ray source in Ghe nt, energies just above and just below the edge of an element were pro duced to identify this particular element by means of the absorption c haracteristics. Identification and quantitative analysis were possible for several heavy elements in samples of known composition. Unknown t argets (pieces cut from uranium ore) were analysed as well, and the re sults obtained with the absorption method were compared with X-ray pho tographs taken of the surface of these pieces. Finally, two-dimensiona l heavy element tomographies were performed.