Near K-edge measurement of the X-ray attenuation coefficient of heavy elements using a tuneable X-ray source based on an electron LINAC

The X-ray attenuation coefficients of bismuth and of uranium were measured in the regions of 40-240 and 70-240 keV, respectively, using a tuneable har d X-ray source based on the linear electron accelerator at the University o f Ghent. Results were compared with the semi-empirical values of Storm and Israel and to the theoretical values of Berger and Hubbell. We also propose a simple function for the attenuation coefficient in the vicinity of the K -edge for uranium and in an extended range of energy for bismuth. The set-u p of the source at Ghent is described and the future improvements are expla ined. (C) 2000 Elsevier Science Ltd. All rights reserved.