Low-Noise Front-End Electronics for Semiconductor X-Ray and Gamma-Ray Detectors

摘要

This thesis deals with improving the performance of semiconductor X-ray and gamma-ray detection systems with the help of low-noise analog electronics. Several methods were used to improve the performance of the detection systems: using optimum preamplifier topologies, cooling the detector and input FET in order to reduce leakage currents and noise, using low-noise JFETS as input devices of the preamplifier, matching the JFET gat capacitance as closely as possible with the detector capacitance, using good-quality low-loss materials for mounting the detector and the JFET in order minimize the dielectric noise, and using rise-time discrimination at the pulse-shaping amplifier in order to reduce the effect of photon events that have experienced charge carrier trapping in the detector materials.