PHOTON INTERACTION CROSS-SECTIONS AND ANOMALOUS SCATTERING FACTORS OFCU AND AG

Total attenuation cross sections of copper and silver have been measur ed in the energy range 5 to 85 keV in a narrow beam good geometry set up using X- and gamma-rays emitted from radio isotopes, by employing a high resolution hyper pure germanium detector. From the measured valu es, the photoeffect cross-sections have been derived by subtracting a small contribution of the sum of the theoretical coherent and incohere nt scattering cross sections. The photoeffect cross-sections so obtain ed are found to be in better agreement with the unrenormalized values of Scofield [10]. These photoeffect cross-sections have been used to e valuate the dispersion corrections (also called anomalous scattering f actors) f(+) and f'' for the forward Rayleigh scattering amplitude by a numerical evaluation of the dispersion integral that relates them at the energies at which the cross-sections have been measured. To the f (+) values so obtained, the relativistic corrections proposed by diffe rent investigators are included separately and the values f' so obtain ed are compared with the available data and discussed. Possible conclu sions are drawn From the present study.