New Generation GridPix: Development and characterisation of pixelated gaseous detectors based on the Timepix3 chip

Due to the increasing demands of high energy physics experiments there is a need for particle detectors which enable high precision measurements. In this regard, the GridPix detector is a novel detector concept which combines the benefits of a pixel chip with an integrated gas amplification structure. The resulting unit is a detector sensitive to single electrons with a great potential for particle tracking and energy loss measurements. This thesis is focusing on the development of a new generation of GridPix detectors based on the Timepix3 chip, which implements a high resolution Time to Digital Converter (TDC) in each pixel. After an introductory chapter describing the motivation behind GridPix, the manuscript presents the physics of gaseous detectors in chapter 2 along with the gaseous detectors used for particle tracking in chapter 3. Chapters 4 and 5 are focusing on the tracking performance of GridPix detectors. Chapter 4 presents results obtained with a GridPix detector based on a small scale prototype chip that was designed towards the development of the Timepix3. Chapter 5 presents the result obtained using a detector based on a full size Timepix3 chip. Finally, chapter 6 concerns the reliability of the detector and presents results obtained with dummy and real Timepix3 chips from measurements performed in harsh radiation environments. The research that has been performed in the context of this thesis shows the great potential of GridPix detectors for future tracking applications. Pixel chips with improved specifications can improve further the position resolution along the drift direction, which can be comparable to the in-plane position resolution. Moreover GridPix detectors equipped with high uniformity protection layers would be able to suppress all the discharges in the future. However the production techniques should be optimised further so that GridPix becomes a mature technology.