Designing a Silicon Drift Detector essentially concerns the definition and optimization of the elementary structures from both the geometrical and technological point of view, in order to guarantee good spatial resolution and reliable operation of the device. Taking into account the complexity of a SDD, the first step towards the production of a prototype is necessarily an extensive numerical simulation of its electrical behaviour. The simulation of a complete large area detector cannot be performed because of the huge amount of memory required. Hence the calculation has to be done on limited portions of the device, introducing artificial boundary conditions.
We use a 2D approximation, though semiconductor detectors are three-dimensional structures and a simulator solving the 3D differential equations would in principle be required. This approximation can be done if we consider cross sections orthogonal to the cathodes in such a way that the partial derivative along the third dimension is negligible.
In these pages you find the analysis done for the ALICE-1B detector. We use ATLAS device simulation software produced by SILVACO. The simulations regard the following regions:
Another aspect that influences the performance of a SDD is the environmental condition. In the following link you find some simulations about this problem: