NEXT, high-pressure xenon gas experiments for ultimate sensitivity to Majorana neutrinos

TL;DR

This paper introduces the NEXT high-pressure xenon gas TPC, designed for detecting neutrinoless double beta decay, with potential to explore the Majorana nature of neutrinos at next-generation scales.

Contribution

It presents the design and development of the NEXT-100 detector and discusses its potential for future large-scale experiments to investigate Majorana neutrinos.

Findings

NEXT-100 is under construction and will search for neutrinoless double beta decay.

The technology can be scaled to a 1-ton detector for next-generation sensitivity.

Preliminary R&D results are promising for ultimate neutrino physics sensitivity.

Abstract

In this paper we describe an innovative type of Time Projection Chamber (TPC), which uses high-pressure xenon gas (HPXe) and electroluminescence amplification of the ionization charge as the basis of an apparatus capable of fully reconstructing the energy and topological signature of rare events. We will discuss a specific design of such HPXe TPC, the NEXT-100 detector, that will search for neutrinoless double beta decay events using 100-150 kg of xenon enriched in the isotope Xe-136. NEXT-100 is currently under construction, after completion of an accelerated and very successful R&D period. It will be installed at the Laboratorio Subterr\'aneo de Canfranc (LSC), in Spain. The commissioning run is expected for late 2013 or early 2014. We will also present physics arguments that suggest that the HPXe technology can be extrapolated to the next-to-next generation (e.g, a fiducial mass of 1 ton of target), which will fully explore the Majorana nature of the neutrino if the mass hierarchy is inverse.