Upgrade and performance studies of a CMOS pixel sensor for the future circular colliders

The Future Circular Collider (FCC-hh) is a new particle collider designed to provide proton-proton collisions with a center-of-mass energy of 100 TeV and an integrated luminosity of 30 ab−1 for 25 years of operation. With the center-of-mass energy it has, FCC-hh is aimed to not only test the Standard Model (SM) and Beyond Standart Model (BSM) theories with high precision but also try to observe unknowns of the universe such as dark energy and dark matter. Therefore, the FCC-hh detector has to be capable of measuring the particles in the environment. However, when such large center-of-mass energy is reached, difficulties arise especially in terms of technology. The most important of these, the radiation levels around the beamline, is beyond today's technologies. Another major challenge at that energy for the detector and physics studies is a large number of p-p collisions that lead to an increase of simultaneous events per bunch crossing known as pile-up. The observation of rare physics events may be obstructed due to the high pile-up environment. These pile-up events can be determined by silicon pixel sensors which have a high granularity structure, good time resolution and radiation hardness. The MALTA sensor is a state-of-the-art radiation hard monolithic silicon pixel sensor with a small collection electrode produced by Tower Semiconductor for 180 nm CMOS imaging technology. The MALTA pixel sensor has been started to develop from experiences with ALPIDE sensor to be used in HL-LHC upgrades of the inner tracker of the ATLAS experiment considering the demanding radiation levels and high pile-up environment of the detector. Thanks to its improvable structure, it is also considered a candidate pixel sensor for the inner tracker of the FCC-hh detector. In this thesis, details of the development process of the MALTA pixel sensors are discussed with respect to the laboratory and test beam results. After that, the time resolution performance of the MALTA sensor is tested with Higgs self-coupling (gg\rightarrow HH\rightarrow b\bar{b}\gamma\gamma) physics process study including realistic detector effects and pile-up environment of the FCC-hh detector within the DELPHES simulation. Consequently, the thesis is concluded with a discussion of the possible usage of the MALTA sensor in the FCC-hh detector based on its radiation performance and time resolution.