Beyond Standard Use Cases: Advancing Dual-Phase Xenon Time Projection Chambers for High-Energy Searches and High-Background Environments

Dual-phase xenon time projection chambers (TPCs) are among the leading technologies for rare-event searches. Their main science goal is the search for weakly interacting massive particles (WIMPs), one of the best motivated candidates for dark matter. This thesis presents developments in two complementary areas that extend the capabilities of xenon-based TPCs beyond their standard use cases. A fast simulation framework was developed for XENONnT to enable rapid, high-statistics studies of detector response in energy regimes where full-chain simulations are computationally costly. It includes a dedicated macro-clustering algorithm based on machine learning to encode the detector's resolution of multi-scatter events. The framework captures the essential features of the detector response and is designed to evolve alongside improvements in the XENONnT analysis chain. The PANCAKE facility is a liquid-xenon test platform capable of accommodating large-scale detector components inside a 2.75 m cryostat. A shallow dual-phase TPC with a diameter of 133 cm was stably operated using a total of about 340 kg of xenon. This represents the first operation of a TPC of this scale in an unshielded above-ground environment. This work describes the dedicated analysis chain developed to interpret the data and presents measurements of the free electron lifetime, the drift velocity, and the effective energy threshold. Additionally, the Doberman slow-control system is presented. Designed for small- and medium-scale setups, it provides a modular and robust infrastructure for monitoring and controlling diverse experimental setups. An integrated web interface offers real-time visualization, configuration, and remote access to all monitored data. Among other applications, Doberman enabled stable and well-controlled operation of the PANCAKE TPC during several months of data taking.