title: Ageing studies of TPB in noble gas detectors for dark matter and neutrinoless ββ decay searches.
abstract: Noble gases (Xe, Ar, Kr) are very attractive as detector media in Dark Matter search and neutrinoless double-beta decay experiments. However, the detection of their scintillation light (in the VUV spectral region) requires shifting the VUV light to visible light, where standard photosensors are more efficient. Tetraphenyl butadiene (TPB) is widely used as wavelength shifter, absorbing the VUV light and re-emitting in the blue region (~430nm). TPB is an organic molecule that may degrade due to exposure to environmental agents and also to ultraviolet light. In this work, we present TPB ageing studies due to exposure to VUV light, aiming at quantifying the reduction of the absolute fluorescence yield of TPB coatings of several thicknesses (130nm, 260nm, 390nm, 1600nm), exposed to various doses of VUV light at 170nm (similar to the Xe scintillation). In our setup, the VUV light is produced from a vacuum monochromator coupled to a deuterium lamp. The VUV exposure in our setup is compared to the exposure obtained in the electroluminescent gaseous Xe TPC of the NEXT-100 experiment for neutrinoless double-beta decay search.
authors.affiliation: Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain. Electronic address: Nadia.Yahlali@ific.uv.es.
authors.forename: N
authors.initials: N
authors.lastname: Yahlali
authors.affiliation: Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Garcia
authors.affiliation: Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Díaz
authors.affiliation: Instituto de Ciencia Molecular (ICMOL), Universitat de València, Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Soriano
authors.affiliation: LIBPhys, Department of Physics, University of Coimbra, 3004-516 Coimbra, Portugal.
authors.forename: L M P
authors.initials: LM
authors.lastname: Fernandes
keywords: Electroluminescence; High pressure xenon gas; Neutrinoless double-beta decay; Time projection chamber (TPC); Wavelength shifter