DIFFERENTIAL SCATTERING CROSS-SECTIONS FOR 8 KEV PHOTONS IN KAPTON AND CRYSTALLINE TARGETS

The model adopted for the calculation of the atomic scattering (Raylei gh or Compton) cross-sections in a material assumes that each atom sca tters independently of the others (isolated or independent atomic mode l approximation). An investigation of the accuracy of this model was p erformed by measuring differential scattering (Rayleigh plus Compton) cross-sections for 8 keV photons in a medium of low atomic number (Kap ton) and in two crystalline targets (silicon and copper). The results for Kapton are in good agreement with theory but for the two crystalli ne targets there is a large discrepancy owing to diffraction phenomena . For this case, the influence of the crystal perfection of the target on the experimental scattered yield is discussed.