Usage of PEN as self-vetoing structural material in low background experiments

TL;DR

This paper explores PEN plastic as a self-vetoing structural material for low-background physics experiments, highlighting its scintillation, mechanical, and radiopurity properties, and reports on its application in the LEGEND-200 experiment.

Contribution

It presents the development and evaluation of PEN-based structures as active, radiopure components for background reduction in rare event detection experiments.

Findings

PEN scintillates effectively in the blue spectrum.

PEN structures demonstrate excellent radiopurity.

Successful integration into LEGEND-200 setup.

Abstract

PEN is an industrial polyester plastic which has become interesting for the physics community as a new type of plastic scintillator. PEN scintillates in the blue regime, which is ideal for most photosensor devices. In addition, PEN has excellent mechanical properties and very good radiopurity has been achieved. Thus, it is an ideal candidate for active structural components in low-background experiments. One possible application are holders for germanium detectors operating in cryogenic liquids (LAr, LN2). Such structures can help to reject surface and external backgrounds, boosting the sensitivity of experiments. In this contribution, the R\&D on PEN is outlined and an evaluation of the first production of PEN structures for the LEGEND-200 experiment is reported.