VERIFICATION OF INCOHERENT-SCATTERING FUNCTIONS AT INTERMEDIATE PHOTON MOMENTUM-TRANSFER

Experimental whole atom differential incoherent scattering cross secti ons were measured for Cu, Mo, Ag, Cd, Sn, Pr, Sm, Gd, Dy, Ho, Yb, Ta, W, Th and U for the 90-degrees scattering of 145.4 and 84.3 keV gamma rays. The scattering experiments were conducted in a reflection geomet ry set up with a graded shielding arrangement. A 133 cm3 HpGe detector was used to detect the scattered gamma rays. The cross sections were measured using Al as standard. From the measured cross sections the in coherent scattering functions were extracted. The results are compared with theory and with the experimental values reported in literature f or available cases. The electron binding effects and the validity of t he incoherent scattering functions at intermediate momentum transfer a re discussed.