Speaker
Description
The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment that seeks to address fundamental questions in particle physics, including neutrino mass ordering and the possible CP violation in the lepton sector that can provide information on the matter–antimatter asymmetry of the universe. A critical challenge in DUNE is the detection of scintillation light from neutrino interactions in LAr emitted at 127 nm, outside the sensitivity range of conventional photodetectors. To enable detection, this vacuum ultraviolet (VUV) light must be wavelength-shifted to the visible range (~420 nm) using materials such as para-Terphenyl (pTP). The proposed photon detection System (PDS) of DUNE Phase-II Far Detector (FD3) requires ~2000 m² of wavelength-shifting filter coverage to achieve a mean light yield of 180 PE/MeV. This corresponds to a production requirement of ~100k pieces of filter plates, each with the current PDS dimensions of 143.5 mm x 143.5 mm. We aim to develop and validate a scalable, cost-effective wavelength shifter coating technology in collaboration with industry. This study investigates the use of industrial vacuum vapor deposition to produce high-quality, uniform pTP coatings with improved process control. The samples produced have been characterized using a UV monochromator and synchrotron light source at NSLS-II with measurements of emission spectra and light yield, while the coating thickness was measured by profilometer. Preliminary results show promising consistency and performance improvements over lab-scale coatings. Furthermore, the pTP-coated filters are planned to be cold-tested in the 260-L LAr test stand at BNL to demonstrate reliable performance under cryogenic conditions, offering a scalable coating solution for FD3. This work advances the development of robust photon detection systems for all noble-element detectors and contributes to detector R&D aligned with DOE scientific missions.
