Ageing studies of TPB in noble gas detectors for dark matter and neutrinoless beta beta decay searches

作者：Yahlali N^*; Garcia J M; Diaz J; Soriano A; Fernandes L M P

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2017, 172: 109-114.

DOI：10.1016/j.saa.2016.04.025

• Neutrinoless double-beta decay
• High pressure xenon gas
• Time projection chamber (TPC)
• Electroluminescence
• Wavelength shifter

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 (similar to 430 nm). 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 (130 nm, 260 nm, 390 nm, 1600 nm), exposed to various doses of VUV light at 170 nm (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.

• 出版日期2017-2-5