Development of BJT radiation sensors and read-out systems for Radon detection

In this thesis we present a novel BJT (Bipolar Junction Transistor) detector that was developed and optimized for alpha particle and radon detection and monitoring. Using functional tests, we have shown that BJT detector operated with floating base can efficiently be used for the purpose of alpha-particle and, consequently, radon gas detection. Basing on these results, we have designed and fabricated a new batch of optimized BJT detectors. The results of electrical and functional characterization of newly fabricated detectors were presented in this work. Fabricated detectors observed high gain, low leakage currents and good detection properties. In parallel to the development of the detector, we successfully designed and implemented FPGA-based readout electronics ALPHADET. Design of the board and results of electrical tests of the board along with extensive data acquired by BJT detectors coupled to the board are presented in the thesis as well. The results of radon tests acquired using BJT detector confirmed that the detector can be successfully used in systems for radon monitoring.