Increasing the efficiency of photon collection in LArTPCs: the ARAPUCA light trap

The Liquid Argon Time Projection Chambers(LArTPCs) are a choice for the next generation of large neutrino detectorsdue to their optimal performance in particle tracking and calorimetry. The detection of Argonscintillation light plays a crucial role in the event reconstructionas well as the time reference for non-beam physics such as supernovae neutrino detection and baryon numberviolation studies. In this contribution, we present the current R&D work on the ARAPUCA ( ArgonR&D Advanced Program at UNICAMP), a light trap device to enhance Ar scintillation light collection and thus the overall performance of LArTPCs. The ARAPUCA working principle is based on a suitable combination of dichroic filtersand wavelength shiftersto achieve a high efficiency in light collection. We discuss the operational principles, the last results of laboratory tests and the application of the ARAPUCA as the alternative photon detection system in the protoDUNE detector.