Sprecher
Beschreibung
We present a theoretical study of the Compton scattering of photons by K-shell electrons of a target atom. Special attention is paid to the polarization of the scattered photons for the case when the incident photons are themselves linearly polarized. In order to explore this polarization transfer we employ the S-matrix approach and the density matrix theory. Moreover, the S-matrix results are compared with the predictions of the well-known impulse approximation (IA), thus allowing to clarify the role of electron binding in polarization studies. Detailed IA and S-matrix calculations have been performed for hydrogen, xenon, and uranium targets, and for photon energies ranging from just above the K-shell ionization threshold to ten times above it. Based on these calculations, we conclude that the impulse approximation is suitable for describing the polarization of scattered photons only for their energies near the Compton peak. If the scattered photon is observed with higher or lower energy, electron binding can strongly affect the polarization transfer, which is clearly evident from the significant discrepancy between the S-matrix and impulse approximation predictions.
