R&D in LAr optical read-out

This task focuses on innovation in scintillation light readout in large liquid argon detectors, covering the development of light collection readout methods: photo-sensors and electronics, new wavelength shifting methods and light calibration. The goals of this task are the characterisation of the new photon detection methods, calibration devices and readout electronics in dedicated test-stands; the implementation and characterisation of a more efficient light collection system in large liquid-argon detectors (based on Xe doping and WLS coated reflective foils); the dissemination of R&D results and light-collection performance. This document includes a summary of the R&D activities on liquid argon light readout developed by the Milano Bicocca, Edinburgh and CIEMAT groups.