Study of PEN Scintillator Properties for Low-Background Applications in the LEGEND Experiment*

In the era of ton-scale low-background experiments, there is an increasing necessity for low background active components capable of tracking residual radiation.  The LEGEND Experiment (Large Enriched Germanium Neutrinoless Double Beta Decay Experiment is currently constructing its 200-kg phase and preparing a 1000-kg phase, which have background goals of 0.5 and 0.025 counts/ton/year/FWHM, respectively.  One method to improve the background identification in LEGEND is to use active structural materials like PEN or poly(ethylene-2,6-naphthalate). PEN is of interest because of its robust structural characteristics and its scintillation light in the blue region as well as its wavelength shifting abilities. Luminescent and optical properties, including the quenching factor, surface reflectivity and attenuation length, have been measured in an effort to support utilizing this material in low background detectors. In addition, the radiopurity of PEN detector holders manufactured in a low-background environment has been measured using both ICP-MS and gamma-ray counting. Results and methods of these measurements will be presented.