ATLAS Technical Coordination WAterLeakDetection project (WALD)

The detection of water leaks inside the service caverns of ATLAS detector is a critical concern due to potential damage to sensitive electronics. Sensing wires are used to monitor the detector and its infrastructure. To improve the detection of small leaks that have increased recently due to the corrosion of pipe joints, the Technical Coordination Water leak project developed and deployed a novel water leak detector based on ``Smart Paper'' developed by the University of Washington. The new material combines cellulose and carbon nanotubes yielding a paper-like whose intrinsic resistance increase by the order of several thousand percent upon absorption of liquids. The material's texture enables the installation of the detector in complicated geometries like for example being wrapped around joints. This summer student project investigated the intrinsic resistance during absorption and drying of the material to provide data to model the response. The model can be used for detector optimisation, degradation studies and to enhance the so-far binary leak detection with an estimation of the amount of detected water.