Mitigation Strategies for ${}^{42}$Ar/${}^{42}$K Background Reduction using Encapsulation with Ultra-Pure Plastic for the LEGEND Experiment

TL;DR

This paper explores encapsulation techniques using ultra-pure plastics to reduce ${}^{42}$K background in the LEGEND experiment's search for neutrinoless double-beta decay, aiming to improve detection sensitivity.

Contribution

It introduces a novel encapsulation approach with 3D-printed, low-background materials to mitigate ${}^{42}$K background in germanium detectors for the LEGEND experiment.

Findings

Simulation results show PEN encapsulation effectively reduces background.

Plans to test additional materials for encapsulation are underway.

Encapsulation could enhance the sensitivity of neutrinoless double-beta decay searches.

Abstract

Neutrinoless double-beta (0$\nu\beta\beta$) decay is the most compelling approach to determine the Majorana nature of neutrino and measure effective Majorana neutrino mass. The LEGEND collaboration is aiming to look for 0$\nu\beta\beta$ decay of ${}^{76}$Ge with unprecedented sensitivity. If underground-sourced argon is not available, the cosmogenically-induced isotope ${}^{42}$Ar and its decay progeny ${}^{42}$K in the liquid argon active veto could create a challenging background for the 0$\nu\beta\beta$ signal. We are studying methodologies to mitigate the ${}^{42}$K background. In order to achieve this, encapsulation of germanium detectors with 3D-printed technologies using low background material are currently under investigation. Simulation results of Poly(ethylene 2,6- naphthalate) (PEN) encapsulation of germanium detectors and plans to study other potential materials are presented.