3D modeling of Cd(Zn)Te detectors for the SIMBOL-X Space mission

Operating in the 0.5 - 70 keV energy range, Simbol-X is a next generation hard X-ray space mission proposed by a collaboration of European laboratories for high energy astrophysics. Simbol-X will consist of two satellites flying in formation. In the first satellite, an X-ray mirror, having a focal length of 30 m, will focus the X-rays on the second satellite containing a silicon low energy detector on top of a Cd(Zn)Te (CZT) high energy detector. The latter consists of a mosaic of - 1 cm(2) elementary arrays with 256 pixels (0.5 x 0.5 mm(2)). As a first step in the development, a prototype CZT detector of 10 x 10 x 2 mm(3), having one side covered with 0.9 x 0.9 mm(2) pixels, is used. A 3-D modeling is performed of the latter. The photon interaction inside the detector is simulated. The spatial distribution of the energy deposition and the amount of charge sharing of the pixels are obtained. The results serve as input parameters for the development and choice of the detector final geometry and electronics.