Development of an FPGA-based DAQ system and power integrity analysis of the pixel sensor for the upcoming Belle II vertex upgrade

Sumitted to PubDB: 2026-05-01

Category: Master Thesis

Tags: Upgrade

Principal Authors Tobias Blesgen
Date 2025-09-07
Belle II Number BELLE2-MTHESIS-2026-013
Abstract Sensor development for particle physics experiments is a complex process that spans multiple years. The associated work does not end once the sensor is designed, but involves detailed computer aided analysis of the design and the preparation of test systems. The development of the Optimized Belle II pixel sensor (OBELIX) is a collaborative effort of multiple institutes to create a next-generation sensor for the particle physics experiment Belle II in Japan. This thesis focuses on simulation-based work for the OBELIX sensor during the critical transition phase from the virtual design work to the physical hardware. OBELIX is designed to be integrated into the Belle II experiment as part of a planned detector upgrade - the VTX upgrade. Chapter 2 introduces the current Belle II detector, the upgrade plans and the OBELIX sensor itself. OBELIX-1 is the first revision of the OBELIX sensor. To test its capabilities and identify issues to be improved upon in the final sensor iteration, OBELIX-1 will undergo extensive lab testing and test beam campaigns. The control and readout of the sensor will be realized by an FPGA-based data acquisition system (DAQ). In Chapter 3 the development process of the software and FPGA firmware is discussed. Together with the codebase verification testbenches are introduced and their output displayed. Fast, dense transistor logic, as implemented in the digital periphery of the OBELIX-1 sensor, generates heat due to its power consumption. Related large currents flowing through on-chip supply nets can - when unchecked - lead to large voltage drops, while high current densities in wires are prone to producing failures over time. Investigations of all of these issues are crucial steps before chip production to ensure long living, functional sensor designs. Dedicated power and rail analyses of the OBELIX-1 digital periphery are performed in Chapter 4 covering the different types of analysis. The final chapter Chapter 5 highlights the results presented in this thesis and gives an outlook on future developments.
Institute Bonn

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