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To date in astrophysics, X- and \gamma-ray celestial emissions have been studied almost exclusively through spectral and timing variability analysis. By measuring the angle and degree of linear polarization of the detected radiation, it is possible to double the number of observational parameters, allowing better discrimination between different astrophysical models. Therefore, future \gamma-ray telescope instrumentation should include the capability to perform high sensitivity polarimetric measurements. This idea has recently become even more appealing in the perspective of new very sensitive \gamma-ray focusing missions equipped with a CdZnTe focal plane, such as the Gamma-Ray Imager and DUAL missions submitted to the European Space Agency's Cosmic Vision calls. By combining the most recent simulation developments and the latest experimental results we present the best polarization assessment so far of such a CdZnTe focal plane when coupled to wide band-pass Laue optics (up to 1 MeV). Firstly, the Laue lens response to different source types (Crab type and monochromatic) was simulated by a Monte Carlo code generating a characteristic PSF (point spread function). Afterwards this PSF served as the input to the focal plane mass model simulation. We have calculated the respective modulation Q factor for on- and off-axis (2') sources. Finally, experimental polarimetric performances of a CdZnTe prototype operating together with Laue lens crystal samples, tested at the European Synchrotron Radiation Facility, validated the focal plane simulation results (Q\sim 0.30 to 0.40, 200 keV to 600 keV range). A minimum detectable polarization of 2% (3\sigma,10^6~s) was estimated for a 100 mCrab, type source, which is compatible with the high polarimetric sensitivity required for space \gamma-ray polarimetry. [ABSTRACT FROM AUTHOR]

To date in astrophysics, X- and gamma-ray source emissions have been studied almost exclusively through imaging techniques, spectral- and timing-variability analysis. However, often two or more distinct models potentially describe the same observations of a particular celestial-radiation source. By measuring the angle and degree of linear polarization of the detected radiation, it is increased by two the number of observational parameters thereby allowing a better discrimination between different models. Therefore, future \gamma-ray-telescope instrumentation should include the capability to perform highly sensitive polarimetric measurements. This idea has recently become even more important from the perspective of new very sensitive hard X- and soft gamma-ray focusing missions based on Laue lenses such as the Gamma-Ray Imager and DUAL missions, submitted to ESA Cosmic Vision calls. In order to optimize the design of a gamma-ray telescope focal plane, a CdZnTe detector prototype has been tested at the European Synchrotron Radiation Facility under a \sim100\\% polarized gamma-ray beam. The tested detector was a 5 mm thick CdZnTe array with segmented anodes into 16\,\times\,16 pixels of 2.5\,\times\,2.5 mm^2. The aim of these tests was to study the polarimetric performance of this prototype as a function of the polarization state of the synchrotron beam. In particular, we determined the sensitivity of the detector to the level of the beam polarization as well as its potential to determine the polarization angle orientation by performing measurements at different polarization direction angles. In both tests the CdZnTe prototype showed a good linearity in its response and good sensitivity to polarization levels down to 50% and a polarization angular resolution better than 5^\circ. [ABSTRACT FROM AUTHOR]