The MAJORANA DEMONSTRATOR: A Search for Neutrinoless Double-beta Decay of Germanium-76

TL;DR

The paper discusses the construction and goals of the MAJORANA DEMONSTRATOR, an underground germanium detector array designed to search for neutrinoless double-beta decay of Ge-76, which could reveal the Majorana nature of neutrinos.

Contribution

It introduces the design and deployment of the MAJORANA DEMONSTRATOR, aiming to achieve ultra-low background levels for future large-scale neutrinoless double-beta decay experiments.

Findings

Design of the germanium detector array

Projected background levels below one count per tonne-year

Feasibility of scaling to a tonne-scale experiment

Abstract

The observation of neutrinoless double-beta decay would determine whether the neutrino is a Majorana particle and provide information on the absolute scale of neutrino mass. The MAJORANA Collaboration is constructing the DEMONSTRATOR, an array of germanium detectors, to search for neutrinoless double-beta decay of 76-Ge. The DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76-Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment. Operation of the DEMONSTRATOR aims to determine whether a future tonne-scale germanium experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76-Ge neutrinoless double-beta decay Q-value of 2039 keV.