Reflectance and fluorescence characteristics of PTFE coated with TPB at visible, UV, and VUV as a function of thickness

Abstract

Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. In noble element systems, it is often coated with tetraphenyl butadiene (TPB) to allow detection of vacuum ultraviolet scintillation light. In this work this dependence is investigated for PTFE coated with TPB in air for light of wavelengths of 200~nm, 260~nm, and 450~nm. The results show that TPB-coated PTFE has a reflectance of approximately 92\% for thicknesses ranging from 5~mm to 10~mm at 450~nm, with negligible variation as a function of thickness within this range. A cross-check of these results using an argon chamber supports the conclusion that the change in thickness from 5~mm to 10~mm does not affect significantly the light response at 128~nm. Our results indicate that pieces of TPB-coated PTFE thinner than the typical 10~mm can be used in particle physics detectors without compromising the light signal.

References in corpus (12)

• The EXO-200 detector, part I: Detector design and construction
• Sensitivity of NEXT-100 to neutrinoless double beta decay
• Reflectance of Polytetrafluoroethylene (PTFE) for Xenon Scintillation Light
• The Next White (NEW) detector
• Calibration of the NEXT-White detector using ${}^{83m}\mathrm{Kr}$ decays
• Radiogenic backgrounds in the NEXT double beta decay experiment
• Photodegradation Mechanisms of Tetraphenyl Butadiene Coatings for Liquid Argon Detectors
• Dependence of polytetrafluoroethylene reflectance on thickness at visible and ultraviolet wavelengths in air
• High Voltage Insulation and Gas Absorption of Polymers in High Pressure Argon and Xenon Gases
• Reflectance dependence of polytetrafluoroethylene on thickness for xenon scintillation light
• Measurements of Angle-Resolved Reflectivity of PTFE in Liquid Xenon with IBEX
• Optical response of highly reflective film used in the water Cherenkov muon veto of the XENON1T dark matter experiment