Monte Carlo polarimetric efficiency simulations for a single monolithic CdTe thick matrix

Polarimetric measurements for hard X- and soft gamma-rays are still quite unexplored in astrophysical source observations. In order to improve the study of these sources through Compton polarimetry, detectors should have a good polarimetric efficiency and also satisfy the demands of the typical exigent detection environments for this kind of missions. Herein we present a simple concept for such systems, since we propose the use of a single thick (∝10 mm) monolithic matrix of CdTe of 32 x 32 pixels, with an active area of about 40 cm2. In order to predict the best configuration and dimension of detector pixels defined inside the CdTe monolithic piece, a Monte Carlo code based on GEANT4 library modules was developed. Efficiency and polarimetric modulation factor results as a function of energy and detector thickness, are presented and discussed. Q factor of the order of 0.3 has been found up to several hundreds of keV. (orig.)