Electric Field Non-Uniformity Mapping for the the Deep Underground Neutrino Experiment (DUNE) ND-LAr 2x2 Demonstrator and Full Scale Demonstrator (FSD)

The 2x2 Demonstrator and the Full Scale Demonstrator (FSD) are prototypes of the Liquid Argon Time Projection Chamber (ND-LAr) that will be used in the Near Detector complex of the Deep Underground Neutrino Experiment (DUNE). These detectors incorporate several innovations to cope with the high level of pile-up expected at ND-LAr, such as the adoption of a modular design and the use of a pixelated charge readout system. To ensure uniformity in the electric field that transports electrons from the ionization points to the anodes, the drift region of each ND-LAr module is surrounded by a novel low-profile resistive field cage. However, field inhomogeneities could still arise from space charge accumulation or other effects, potentially affecting position and energy reconstruction performance in ND-LAr. Using a sample of cosmic-ray muons with well-defined start and exit points, it is possible to study deviations in the reconstruction of original energy depositions caused by distortions in the electric field. This poster will describe the status of the analysis carried out so far to characterize field nonuniformity effects in the 2x2 Demonstrator and the FSD.