Detection of Gamma Ray Polarization Using a 3-D Position-Sensitive CdZnTe Detector

When a polarized gamma ray photon undergoes a Compton scatter, the probability for the photon to scatter at a fixed scattering angle depends on the azimuthal angle. The polarization of incident gamma rays can be measured using this effect by observing the angular distribution of scatters. Room-temperature 3-dimensional position-sensitive CdZnTe detectors can provide good energy resolution as well as positions of interactions, allowing these detectors to perform Compton imaging and polarization detection simultaneously. In this paper, we demonstrate that an pixellated CdZnTe detector with 3-D position sensing capability can be an effective instrument to detect the polarization of incident gamma rays.