Speaker
Description
Liquid argon is commonly used as a detector medium for neutrino physics and dark matter experiments in part due to its copious scintillation light production in response to its excitation and ionization by charged particle interactions. As argon scintillation appears in the vacuum ultraviolet (VUV) regime and is difficult to detect, wavelength-shifting materials are typically used to convert VUV light to visible wavelengths more easily detectable by conventional means. Here we present recent measurements of the wavelength-shifting and optical properties of poly(ethylene naphthalate) (PEN), a proposed alternative to tetraphenyl butadiene (TPB), the most widely-used wavelength-shifter in argon-based experiments. The measurements were performed in a custom cryostat system with well-demonstrated geometric and response stability, with 128~nm argon scintillation light used to examine various PEN-including reflective samples' light-producing capabilities, as well as their stability. The best-performing PEN-including test reflector was found to produce 34% as much visible light as a TPB-including reference sample, with widely varying levels of light production between different PEN-including test reflectors.
