Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array

TL;DR

NEXT-DEMO, a high-pressure xenon gas TPC with a silicon photomultiplier tracking array, successfully demonstrates electron track reconstruction and achieves excellent energy resolution, validating its design for neutrinoless double beta decay searches.

Contribution

This paper presents the first operation and results of the NEXT-DEMO prototype using a SiPM tracking array, showcasing its capabilities for electron tracking and energy measurement.

Findings

Achieved 1.82% FWHM energy resolution at 511 keV

Successfully reconstructed electron signatures including MIP and blob regions

Validated design for future neutrinoless double beta decay experiments

Abstract

NEXT-DEMO is a high-pressure xenon gas TPC which acts as a technological test-bed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current configuration the apparatus fully implements the NEXT-100 design concept. This is an asymmetric TPC, with an energy plane made of photomultipliers and a tracking plane made of silicon photomultipliers (SiPM) coated with TPB. The detector in this new configuration has been used to reconstruct the characteristic signature of electrons in dense gas. Demonstrating the ability to identify the MIP and "blob" regions. Moreover, the SiPM tracking plane allows for the definition of a large fiducial region in which an excellent energy resolution of 1.82% FWHM at 511 keV has been measured (a value which extrapolates to 0.83% at the xenon Qbetabeta).