System Tests and the Development of Detector Control Systems for the ATLAS Inner Tracker and the FASER Experiment

To exploit the collider’s full potential, the LHC will be upgraded to the High Luminosity-LHC. The instantaneous luminosity will increase five- to sevenfold from luminosities achieved during LHC Run 3. To cope with the resulting increase in occupancy, bandwidth and radiation damage, ATLAS will replace the Inner Detector with an all-silicon system, the Inner Tracker (ITk). The innermost part of the ITk will consist of a hybrid pixel detector with five layers that will consist of modules combined into serially powered (SP) chains and loaded on ring and stave shaped low mass carbon fiber local supports (LLS).

Validating this design requires rigorous system tests using prototypes. One such system test was conducted using the demonstrator for the Outer Barrel (OB) region. A prototype longeron LLS was intensively tested and its performance evaluated. This thesis presents the results of these tests, which validate the overall system design for the OB region.

Following successful validation, the project has entered the preproduction phase for LLSs. During preproduction, the Quality Control (QC) setups, that will be used during production, are being qualified. This thesis presents results from qualification steps of the CERN OB LLS Quality Control (QC) setup, as well as developments for all OB LLS QC setups to enable efficient testing during production.

For the safe operation of these QC setups, a sophisticated Detector Control System (DCS) was developed. The operational model of the detector was translated into the state model of a Finite State Machine (FSM) ensuring safe operation. This thesis presents the control system, including benchmarks showing its suitability for even larger systems.

FASER is a small forward experiment 480 m from the ATLAS interaction point and searches for new particles in regions not accessible by ATLAS. This thesis also presents contributions made to the FASER DCS to integrate a new Water Leak Detection system and to control the new Preshower upgrade of FASER with a completely newly developed control system.