Collision Integral Cross Section Measurements in Two-Photon Compton Scattering

The collision integral cross sections in two-photon Compton scattering are measured experimentally for 0.662 MeV incident gamma photons. Two simultaneously emitted gamma quanta are investigated using a slow-fast coincidence technique of 25 ns resolving time. The coincidence spectra for different energy windows of one of the two final photons are recorded using HPGe detector. The experimental data do not suffer from inherent energy resolution of gamma detector and provide more faithful reproduction of the distribution under the full energy peak of recorded coincidence spectra. The present results of collision integral cross sections are in agreement with the currently acceptable theory of this higher order process. (author)