Effective atomic numbers for photoabsorption in alloys in the energy region of absorption edges

For photon interactions, the effective atomic numbers for 25 alloys containing different elements from carbon to bismuth at energies 10, 20, 30, 40 60, 80, 100 and 150 keV are derived. It is expected that the number should not vary with energy in this energy region, since photoabsorption is the dominant process. But, it is noticed that the number is not the same for alloys in the energy region of their respective constituent elemental photoabsorption edges. However, above the energy of the K absorption edge of the highest atomic number involved in each alloy, the number for photoabsorption more or less remains the same. (C) 1998 Elsevier Science Ltd. All rights reserved.