Measurements of Singly Differential Collision Cross Sections of Double-Photon Compton Scattering of 662-keV Gamma Photons

Abstract

The singly differential collision cross sections of the double-photon Compton process have been measured for 662-keV incident gamma photons by using a single-gamma-ray detector. This technique avoids the use of the complicated slow-fast coincidence setup used until now for observing this higher-order process. The measured values of the singly differential collision cross section are of the same magnitude but deviate from the corresponding values calculated from the theory and are nearly α (fine-structure constant, ≅ 1/137) times the Klein-Nishina cross-section value for different scattering angles.