Low Background Materials and Fabrication Techniques for Cables and Connectors in the Majorana Demonstrator

TL;DR

This paper discusses the development of ultra-pure, low-background cables and connectors crucial for the success of the Majorana Demonstrator in detecting neutrinoless double-beta decay, emphasizing materials and fabrication techniques.

Contribution

It presents specific materials and fabrication methods for cables and connectors that minimize radioactive background in ultra-pure environments for neutrino experiments.

Findings

Successful implementation of low-background cables and connectors

Plans for upgrading wiring for higher reliability

Guidelines for future LEGEND R&D efforts

Abstract

The MAJORANA Collaboration is searching for the neutrinoless double-beta decay of the nucleus Ge-76. The MAJORANA DEMONSTRATOR is an array of germanium detectors deployed with the aim of implementing background reduction techniques suitable for a tonne scale Ge-76-based search (the LEGEND collaboration). In the DEMONSTRATOR, germanium detectors operate in an ultra-pure vacuum cryostat at 80 K. One special challenge of an ultra-pure environment is to develop reliable cables, connectors, and electronics that do not significantly contribute to the radioactive background of the experiment. This paper highlights the experimental requirements and how these requirements were met for the MAJORANA DEMONSTRATOR, including plans to upgrade the wiring for higher reliability in the summer of 2018. Also described are requirements for LEGEND R&D efforts underway to meet these additional requirements.