Study and characterization of WLS for ARAPUCA to DUNE experiment

The photon detection system of the far detector of the Deep Underground Neutrino Experiment (DUNE) will collect liquid argon scintillation photons with an array of modules whose working principle is based on the ARAPUCA technology. These devices acting as light traps are able to convert VUV scintillation photons into visible ones and capture them inside a reflective cavity observed by an array of SiPMs as active photo-sensitive elements. The use of wavelength shifting techniques in light collecting systems for particle detection in liquid argon is of fundamental importance, since the scintillation photon wavelength is around 127 nm of the photon produced which is extremely challenging to be directly detected. The main objective of the present work was to explore and characterize different substrates, wavelength shifting compounds and deposition methods to optimize and improve the light collection of the ARAPUCA device.