NEXT-DEMO: a prototype for the NEXT experiment

TL;DR

NEXT-DEMO, a large xenon TPC prototype, demonstrates the feasibility of achieving near-optimal energy resolution for neutrinoless double beta decay searches, advancing detector technology for rare event detection.

Contribution

The paper presents the construction and operation of NEXT-DEMO, showing improved light collection and energy resolution, validating the detector concept for the NEXT experiment.

Findings

Achieved 2.3% FWHM energy resolution at 511 keV

Extrapolated to 1% FWHM at Qbb energy

Validated the feasibility of the NEXT detector design

Abstract

NEXT is a high-pressure (10-15 bar) xenon Time Projection Chamber dedicated to neutrinoless double beta decay searches. NEXT-DEMO is a large prototype of the NEXT experiment, constructed to demonstrate the feasibility of the NEXT detector concept, in particular the capability of the TPC to achieve an optimal energy resolution at the Xe Qbb energy (2.458 MeV). It has been operating at IFIC, in Valencia, for one year and a half and a number of results has been achieved. Recently, the reflector panels of the prototype have been coated with a wavelength shifter (TPB), in order to improve light collection. We have obtained an energy resolution of 2.3% FWHM at 511 keV, using Na-22 radioactive sources, corresponding to 1% FWHM once extrapolated to Qbb.