Studies on the Calibration and Optimisation of Detector Response in Liquid Argon Time Projection Chambers for Neutrino Experiments

Neutrino physics has advanced to the point where all neutrino oscillation parameters have been determined, with current generation neutrino experiments probing new discoveries in the field such as the sterile neutrino. This is a fourth neutrino flavour that only couples to gravity, and is theorised to be the cause of previously measured anomalies in neutrino oscillation physics. The Short-Baseline Neutrino program will perform high resolution νµ and νe oscillation measurements from the Booster Neutrino Beam (BNB), utilising ICARUS and the Short-Baseline Near Detector (SBND). SBND is a Liquid Argon Time Projection Chamber (LArTPC), placed 110 m from the BNB target, allowing for high precision neutrino-argon cross-section measurements. This thesis presents a methodology characterising the timing drift and resolution of cosmic-ray taggers before their installation around the SBND cryostat, allowing for full cosmic-ray background mitigation. Also featured is a procedure for validating the detector response modelling algorithms used in SBND software, comparing the expected response to average waveforms reconstructed from Monte Carlo event samples and SBND data. SBND is expected to exhibit ambiguities in event reconstruction due to using planes of sense wires to read out charge, motivating a pixelated charge readout for future LArTPC experiments, such as the DUNE near detector. The University of Sheffield provides an R&D experiment for this technology, named STEEL. Scintillation data from a 22-day data run of STEEL is used to calculate singlet, triplet and intermediate decay constants as τ1 = (12.4 ± 0.8) ns, τ3 = (0.715 ± 0.009) µs and τi = (69.6 ± 4.5) ns respectively, with pixel data used to determine the electron lifetime to be τe = (0.491 ± 0.006) µs. Measurements of τ3 and τe leads to average oxygen impurity density calculations of [O2]γ = (1.48 ± 0.04) ppm and [O2]e = (1.42 ± 0.01) ppm respectively.