Characterisation of the LYCCA Double-Sided Silicon Strip Detectors

Abstract: The goal of this thesis work is to describe the methods used and perform comprehensive testing of the Double-Sided Silicon-Strip Detectors (DSSD) prior to their implementation in the Lund-York-Cologne CAlorimeter (LYCCA) detector. In the framework of this project, the DSSD characterisation was carried out to ensure specification compliance prior to their "in-kind contribution" delivery to the HISPEC experiment at the NUSTAR collaboration. NUSTAR is one of the four scientific pillars of the future FAIR international accelerator facility currently under construction in Darmstadt, Germany. The main performance parameters obtained were the DSSD's operating voltage, strip-by-strip resolution, leakage current, etc. Two uncollimated alpha sources, 244Cm and 148Gd were used for the DSSD testing and performance studies. The energy spectra were measured by the dedicated real time data acquisition system. These spectra were analysed using a Python code to extract the detector’s energy and position resolution. The DSSD's operation voltage and leakage current were obtained from the NIM module used for the detector's high voltage biasing. The intrinsic energy resolution was measured to be approx. 100 keV (FWHM) at 5.797 MeV. The measured resolution is higher than expected for this type of DSSD, which can be partially attributed to the electrical noise, non-uniformity of the dead layer thickness, and non-optimal FPGA-based digital signal processing algorithms.