Inelastic and anomalous elastic scattering of 88.03-keV<i>γ</i>rays

Abstract

Cross sections for the elastic scattering of 88.03-keV \ensuremath{\gamma} rays through 125\ifmmode^\circ\else\textdegree\fi{} by aluminum, gold, lead, and bismuth have been measured with a semiconductor detector. Simultaneously, information has been obtained regarding resonance Raman scattering and Compton scattering in the case of bismuth, and K-shell photoeffect cross sections in the case of gold and lead. Values accurate to about 8% were determined with the help of a normalization technique relying on a comparison with the Compton scattering counts from the low-atomic-number aluminum target. The elastic scattering cross section of aluminum at the chosen photon energy, which is far above the aluminum K-shell threshold, is in reasonable accord with form-factor and S-matrix calculations based on the independent-particle approximation. For gold, 7.3 keV above its threshold, the experiment agrees with the S-matrix prediction. However, for lead some 25 eV above threshold, the experimental value is about 40% larger than predicted, while for bismuth (2.5 keV below threshold), experiment lies 70% above theory. The measured K-shell photoeffect cross section of lead is within 10% of the prediction based on the independent-particle approximation.