Design and Development of Sectional-Chain Silicon Drift Detectors with Diversity Elliptical-Shaped Voltage Dividers

This paper proposes a sectional-chain silicon drift detector (SDD), featuring an elliptical-shaped voltage divider resistor chain, that can address the issue with traditional concentric ring SDDs, which cannot independently provide voltage division. The study replaces the conventional linear voltage divider with an elliptical structure, using its diversity geometry to improve the uniformity of the electric field distribution within the detector's sensitive area, effectively solving the problem of distortions of edge electric fields and those between the SDD's cathode rings in traditional structures. The relevant parameters of the elliptical resistor chain are calculated through formulas, which establish a quantitative relationship between the resistance values and the elliptical geometric dimensions, providing a theoretical basis for electric field uniformity control. A device physics model is then established using TCAD for simulation analysis to obtain key performance parameters: the electric potential and electric field distribution inside the detector, the spatial distribution of electron concentration in the detector bulk, and the electric potential gradient on the detector surface. These parameters provide a design reference for the application of high-performance SDDs in fields such as X-ray energy spectroscopy nuclear physics experiments and space radiation monitoring.