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Characterizing Single Event Upsets within the lpGBT-based End-of-Substructure Card

The CERN ATLAS particle physics experiment is currently undergoing a significant system upgrade (ATLAS Phase II upgrade). As a result of the upgrade the experiment's Inner Tracker (ITk) and the front-end electronics of the ITk are being redesigned to handle increased data rates and a higher radiatio...

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Main Author: Naidoo, Joash Nicholas
Other Authors: Wyngaard, Janet
Format: Thesis
Language:English
Published: Department of Electrical Engineering 2022
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access_status_str Open Access
author Naidoo, Joash Nicholas
author2 Wyngaard, Janet
author_browse Naidoo, Joash Nicholas
Wyngaard, Janet
author_facet Wyngaard, Janet
Naidoo, Joash Nicholas
author_sort Naidoo, Joash Nicholas
collection Thesis
description The CERN ATLAS particle physics experiment is currently undergoing a significant system upgrade (ATLAS Phase II upgrade). As a result of the upgrade the experiment's Inner Tracker (ITk) and the front-end electronics of the ITk are being redesigned to handle increased data rates and a higher radiation environment. Within the ITk, the End Of Substructure (EoS) card is a new custom designed digital board that will provide the data, command, and power interface between on and off-detector electronics. Each EoS card makes use of one or two custom CERN designed low power Gigabit Transceivers (lpGBTs) ASICS that have been created for the purposes of supporting high bandwidth optical links in high radiation environments throughout CERN experiments. An estimated 1552 EoS cards will be installed in the ITk, each representing a potential point of failure. Given the complexity and quantity of new hardware designs involved, and that the EoS cards will be not be accessible or serviceable after the upgrade has been completed, there is a need for rigorous quality assurance (QA) and quality control (QC) testing. This thesis therefore describes an independent test setup commissioned, by the author, at the University of Cape Town (UCT) Physics Department for characterising aspects of EoS card's operation under representative radiation conditions. Specifically, the radiation environment of the ITk poses a challenge to electronics as energetic particles can deposit their energy within the circuit material resulting in an erroneous change in logic known as a Single Event Upset (SEU). The lpGBT is a radiation tolerant ASIC and employs digital signal processing (DSP) and triple modular redundancy (TMR) techniques to mitigate against the effects of SEUs on transmitted data. This thesis presents an experiment setup which tests this hypothesis that the DSP stages are susceptible to data corruption caused by SEUs. In addition the setup also attempts to characterize the susceptibility of the scrambler, encoder, and interleaver stages within the lpGBT to SEUs. This experiment is carried out by actively irradiating an EoS card with a neutron source (energy spectrum of up to 11 MeV), while emulating each stage on a non-irradiated off-board FPGA. Additionally and in support of this experiment, the existing firmware and LabView automation software developed at DESY are extended. Results from this thesis indicate that the DSP stages within the lpGBT are susceptible to data corruption caused by SEUs. It was also shown that the susceptibility of the experiment itself did not effect the measured SEU rates. Finally, preliminary results suggest that susceptibility of the DSP stages within the lpGBT can be characterized as the Bit Error Rate (BER) increases depending on the number of active stages.
format Thesis
id oai:open.uct.ac.za:11427/36025
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:32:45.765Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2022
publishDateRange 2022
publishDateSort 2022
publisher Department of Electrical Engineering
publisherStr Department of Electrical Engineering
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/36025 Characterizing Single Event Upsets within the lpGBT-based End-of-Substructure Card Naidoo, Joash Nicholas Wyngaard, Janet Keaveney, James Electrical Engineering The CERN ATLAS particle physics experiment is currently undergoing a significant system upgrade (ATLAS Phase II upgrade). As a result of the upgrade the experiment's Inner Tracker (ITk) and the front-end electronics of the ITk are being redesigned to handle increased data rates and a higher radiation environment. Within the ITk, the End Of Substructure (EoS) card is a new custom designed digital board that will provide the data, command, and power interface between on and off-detector electronics. Each EoS card makes use of one or two custom CERN designed low power Gigabit Transceivers (lpGBTs) ASICS that have been created for the purposes of supporting high bandwidth optical links in high radiation environments throughout CERN experiments. An estimated 1552 EoS cards will be installed in the ITk, each representing a potential point of failure. Given the complexity and quantity of new hardware designs involved, and that the EoS cards will be not be accessible or serviceable after the upgrade has been completed, there is a need for rigorous quality assurance (QA) and quality control (QC) testing. This thesis therefore describes an independent test setup commissioned, by the author, at the University of Cape Town (UCT) Physics Department for characterising aspects of EoS card's operation under representative radiation conditions. Specifically, the radiation environment of the ITk poses a challenge to electronics as energetic particles can deposit their energy within the circuit material resulting in an erroneous change in logic known as a Single Event Upset (SEU). The lpGBT is a radiation tolerant ASIC and employs digital signal processing (DSP) and triple modular redundancy (TMR) techniques to mitigate against the effects of SEUs on transmitted data. This thesis presents an experiment setup which tests this hypothesis that the DSP stages are susceptible to data corruption caused by SEUs. In addition the setup also attempts to characterize the susceptibility of the scrambler, encoder, and interleaver stages within the lpGBT to SEUs. This experiment is carried out by actively irradiating an EoS card with a neutron source (energy spectrum of up to 11 MeV), while emulating each stage on a non-irradiated off-board FPGA. Additionally and in support of this experiment, the existing firmware and LabView automation software developed at DESY are extended. Results from this thesis indicate that the DSP stages within the lpGBT are susceptible to data corruption caused by SEUs. It was also shown that the susceptibility of the experiment itself did not effect the measured SEU rates. Finally, preliminary results suggest that susceptibility of the DSP stages within the lpGBT can be characterized as the Bit Error Rate (BER) increases depending on the number of active stages. 2022-03-10T09:54:12Z 2022-03-10T09:54:12Z 2021 2022-03-08T09:49:57Z Master Thesis Masters MSc http://hdl.handle.net/11427/36025 eng application/pdf Department of Electrical Engineering Faculty of Engineering and the Built Environment
spellingShingle Electrical Engineering
Naidoo, Joash Nicholas
Characterizing Single Event Upsets within the lpGBT-based End-of-Substructure Card
thesis_degree_str Master's
title Characterizing Single Event Upsets within the lpGBT-based End-of-Substructure Card
title_full Characterizing Single Event Upsets within the lpGBT-based End-of-Substructure Card
title_fullStr Characterizing Single Event Upsets within the lpGBT-based End-of-Substructure Card
title_full_unstemmed Characterizing Single Event Upsets within the lpGBT-based End-of-Substructure Card
title_short Characterizing Single Event Upsets within the lpGBT-based End-of-Substructure Card
title_sort characterizing single event upsets within the lpgbt based end of substructure card
topic Electrical Engineering
url http://hdl.handle.net/11427/36025
work_keys_str_mv AT naidoojoashnicholas characterizingsingleeventupsetswithinthelpgbtbasedendofsubstructurecard