Results from the NEXT prototypes

C A B Oliveira,The Next Collaboration

doi:10.1088/1742-6596/460/1/012011

Abstract

NEXT-100 is an electroluminescent high pressure Time Projection Chamber currently under construction. It will search for the neutrino-less double beta decay in 136Xe at the Canfranc Underground Laboratory. NEXT-100 aims to achieve nearly intrinsic energy resolution and to highly suppress background events by taking advantage of the unique properties of xenon in the gaseous phase as the detection medium. In order to prove the principle of operation and to study which are the best operational conditions, two prototypes were constructed: NEXT-DEMO and NEXT-DBDM. In this paper we present the latest results from both prototypes. We report the improvement in terms of light collection (~ 3×) achieved by coating the walls of NEXT-DEMO with tetraphenyl butadiene (TPB), the outstanding energy resolution of 1 % (Full Width Half Maximum) from NEXT-DBDM as well as the tracking capabilities of this prototype (2.1 mm RMS error for point-like depositions) achieved by using a square array of 8 × 8 SiPMs.

Highlights

If the neutrino has a Majorana nature, the neutrino less double beta (0νββ) decay exists in some natural isotopes including 136Xe
NEXT-100 is currently under construction and will search for the 0νββ decay at the Canfranc Underground Laboratory [1]. It consists of an electroluminescent high pressure Time Projection Chamber that will use up to 150 kg of gaseous xenon enriched in the isotope 136Xe to ∼ 91 % as both the source of the decay and the detection medium
In the gaseous phase the fluctuations associated with the production of primary electrons by ionizing particles are very low when compared to those of the liquid phase (∼130 times higher) [2]

Summary

Introduction

If the neutrino has a Majorana nature, the neutrino less double beta (0νββ) decay exists in some natural isotopes including 136Xe. EL is detected by a 2D array of light sensitive detectors (PMTs in the case of NEXT-DEMO and SiPMs in the case of NEXT-DBDM) that lives just next to the EL gap. (a) Schematic of the NEXT-DEMO prototype showing the pressure vessel, the energy and coarse tracking PMT planes, the field cage and the feedthroughs.

Results

Conclusion