Ponente
Descripción
The LEGEND experiment aims to detect the neutrinoless double beta decay of $^{76}$Ge, which would prove the Majorana nature of neutrinos, with a sensitivity for the half-life of $10^{28}$ years. To this end, one tonne of high-purity germanium (HPGe) detectors will be deployed in a segmented liquid argon (LAr) medium, which is used as coolant and instrumented as a detector for the active reduction of backgrounds. To further increase the background suppression efficiency, the scintillating and wavelength shifting polymer polyethylene naphthalate (PEN) will be used throughout the experiment. In this talk, we present the utilization of PEN for replacing optically inactive structural components, HPGe detector encapsulation and large-scale thin films. In order to meet the background limits and light yield requirements of the experiment, custom synthesis and moulding of PEN on semi-industrial scale is pursued. We report on the first results of a successful kilogram-scale production of PEN with full control over the production cycle. In addition, the photoluminescence yield and spectrum of the custom-made PEN after irradiation with VUV photons (128 nm) for temperatures between 300 K and 87 K are shown. Lastly, we give an outlook on further steps in the production and characterization of custom-made PEN.
