Design of the detector control system for the upgrade of the ALICE Muon Tracking Chambers at CERN
Date
2023-03
Authors
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Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: It has been nearly 14 billion years since the big bang created the universe with all the matter that exists today. For this very reason, various scientific research facilities around the globe have dedicated their efforts to unlocking the mystery of our universe and understanding the components of the aftermath of this phenomenon. One of the central research facilities making tremendous leaps in this field is CERN, the European Organisation for Nuclear Research – the site responsible for the HIGGS1 boson discovery. CERN hosts the world’s largest particle accelerator that forms a 17-milelong (kilometres) semiconductor ring under the French-Swiss border near Geneva called the Large Hadron Collider (LHC). Four main detector experiments are installed at specific points around the LHC: ALICE, ATLAS, CMS, and LHCb. These detectors, the size of cathedrals, analyze the many particles that scatter from the collisions in the accelerator. Each experiment is unique and depicted by the design of its detectors. A Large Hadron Collider Experiment (ALICE) is dedicated to heavy-ion physics, in which it looks at and studies the beam collisions from heavy nuclei (Pb-Pb collisions). The experiment is established by eighteen different technologies, all intertwined to do a specific job in studying these collisions. The Muon Spectrometer forms part of the backbone of the ALICE detector and focuses on the study of muons that arise from the decay of heavy-ion collisions. It comprises three of the eighteen technologies that bring life to the ALICE experiment – the front absorbers, muon tracking chambers (MCH), and trigger systems. The ALICE collaboration is undergoing a significant upgrade of its detector in alignment with other detector experiments and the LHC during the Long Shutdown 2 (LS2), scheduled from 2019 to 2022. Over 1000 scientists and engineers from vast parts of the globe collaborate with ALICE to improve the detector to handle the increased luminosity from the LHC during Run 3. The ALICE MCH itself has undertaken multiple years of development and prototyping of its front-end electronics (FEE) along with the upgrade of its power distribution system. Now, well into the start of Run 3, MCH has made headway in its preparedness for the start of data-taking. The upgraded ALICE detector will achieve a readout of data up to 50kHz as opposed to its previous limit of 500 Hz. In addition, the LHC exposes the various systems to harsh conditions (high radiation and magnetic fields) that result from high-energy beam collisions. This means that control system architectures are crucial for each sub-detector during the operation of the accelerator and detector systems. In this thesis, the author will focus on the development of an upgraded Detector Control System (DCS) for the ALICE MCH. This dissertation will first showcase the background information of the current MCH system and then go into detail regarding the evolution from the current DCS to the upgraded architecture – with details regarding the significant changes to the WinCC-OA structure, the new ALICE front-end software, and integration of the upgraded components within the subsystem. Much attention will extend to the new ALICE low-level front-end software (ALF-FRED) that is now integrated by most of the sub-detectors of ALICE. The software, developed by the central ALICE DCS group, is based on several C++ modules that communicate via Distributed Information Management (DIM) over the CERN network, and it offers flexibility to expand its capabilities with the use of custom C++ code to meet the requirements of each sub-detector. The development and integration of ALF-FRED within the DCS platform will be reported, including relevant test bench and final system results. Apart from just the mere control and monitoring of the crucial MCH system parameters, the upgraded DCS architecture will offer the user the ability to configure the FEE of the MCH for specific datataking modes. Previously, this was accomplished outside the current DCS model using external tools. The dissertation will streamline the challenges with achieving this goal across the latter part of this document, pinpointing the crucial and exhausting development work towards attaining the efficient configuration timescales for the FEE utilizing the upgraded DCS platform. The significant results will help complete and validate the ALICE MCH DCS design in its final setting during the test-bench trial runs. A considerable portion of the work detailed by the author represents the ultimate contribution to accomplishing the different phases of development work, leading towards the final upgraded ALICE MCH DCS.
AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.
AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.
Description
Thesis (MEng)--Stellenbosch University, 2023.