A 3-D simulation code of electron-hole transport and signal formation with coulomb repulsion and thermal diffusion in 2-D semiconductor detectors

We developed a simulation code for electron-hole transport and signal formation in semiconductor detectors having 2D geometry, either in linear or cylindrical coordinates. Thermal diffusion and Coulomb interaction between the carriers - essential for the correct simulation of high-density ionization tracks - have been included preserving their full 3D nature. In this way we can solve transport problems in the frequent case of 2D detector geometry with a precise treatment of the Coulomb interaction up to high charge levels. The induced current and induced charge signals at arbitrary electrodes are obtained with a microscopic approach, i.e. by computing the trajectories of the individual carriers. Extensive use of parallel programming has been employed in order to optimize the code for multi-core CPUs. As a realistic case study we present the space-time evolution of the electron-hole cloud resulting from a 7.5 MeV 7Li ion impinging on a double-sided silicon strip detector meant for the identification of charged particles in nuclear physics experiments.