In current and future high-energy physics experiments (i.e. upgrades of large detectors at the LHC and experiments in future colliders), the granularity of particle detectors continues to increase, and the use of multi-channel submicron integrated circuits has become a standard.

This granularity was taken one step further in the field of 'Monolithic Active Pixel Sensor' (MAPS) technology, where pixel sizes can be as small as 10 x 10 µm2. These small pixels make it possible to achieve record spatial resolutions or greatly improve the radiation resistance of the trace detector, at the cost of a large quantity of data produced. This large amount of data is acceptable where a maximum spatial resolution is required, but can be prohibitive when this is not necessary, or when space and consumption constraints put limits on the number of fast downstream links.

Each experiment therefore requires to redefine the combination of the pixel size and the architecture of the detector's readout electronics, in order to meet the occupancy rate requirements of each physics experiment, and the detector's readout capabilities.
A major innovation in the design of pixel sensors for particle physics is to decouple the pixel matrix from the data rate sent.
As part of a team that has been developing MAPS since 1999, the approach required for the thesis is in a first step to study the existing trace detector architecture in order to understand its limitations in terms of radiation resistance. In a second step, the thesis will focus on information grouping options, assessing the impact of these options on data reduction as well as on induced information loss.

This will be supported by the design of a system-on-chip architecture, including pixel array optimization and digital processing, validating the work carried out in an integrated circuit.

To this end, this thesis will focus specifically on one of the major experiments at the European Center for Nuclear Research (CERN): the Upstream Tracker detector for the LHC Beauty Quark Experiment (LHCb).