Material study on the use of silicon carbide in position-sensitive particle detectors

Abstract

In this thesis silicon carbide (SiC) is reviewed as a possible material for particle detectors. Its properties are compared to those of silicon in the form of literature studies, simulations and measurements. Silicon is the most common and best understood particle sensor material, but has certain limitations in terms of radiation hardness. Due to the demand of the chip industry, large-area SiC wafers became available recently. The radiation hardness is supposed to be higher than that of silicon. The high drift velocity leads to shorter signal pulses, which are needed to cover beam rates up to the GHz region. The larger bandgap makes it insensitive to visible light and its higher thermal conductivity can help avoid cooling.The different material properties were simulated using the simulation frameworks Weighfield2, TCAD and Allpix2.At MedAustron (Wr. Neustadt, Austria), an ion therapy center for cancer treatment, a silicon carbide strip sensor prototype was tested. This facility consists of a synchrotron particle accelerator that provides protons with an energy of up to 800 MeV. Bias voltage and energy scans were conducted to determine the full depletion voltage of this sensor and compare its energy deposition to the Bethe-Bloch equation. For further data analysis Corryvreckan, a testbeam data reconstruction software, was used.