First results of the NEXT-100 detector using ${}^{83m}$Kr decays

Abstract

The NEXT collaboration is investigating the double beta decay of ${}^{136}$Xe using high-pressure gas electroluminescent time projection chambers, which provide excellent energy resolution together with a robust topological signature. Operating at the Laboratorio Subterráneo de Canfranc (LSC) and building on the success of the NEXT-White detector, the NEXT-100 apparatus began commissioning in May 2024 and started operation with xenon at a pressure of 4 bar in October 2024. We report here the first results obtained with NEXT-100 using low-energy calibration data from ${}^{83m}$Kr decays, which allow mapping of the detector response in the active volume and monitoring of its stability over time. After homogenizing the light response, we achieve an energy resolution of 4.37% FWHM at 41.5 keV for ${}^{83m}$Kr point-like energy deposits contained in a radius of 425 mm. In a fiducial region representing the operating conditions of NEXT-100 at 10 bar we obtain an improved energy resolution of 4.16% FWHM. These results are in good agreement with that obtained in NEXT-White, and an $E^{-1/2}$ extrapolation to $Q_{\beta \beta }$ yields an energy resolution close to 0.5% FWHM, well below the 1% FWHM design target.

13 pages, 11 figures

References in corpus (19)

• Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen
• Anomaly detection with Convolutional Graph Neural Networks
• Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment
• Ionization and scintillation response of high-pressure xenon gas to alpha particles
• The Next White (NEW) detector
• Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array
• Energy calibration of the NEXT-White detector with 1% resolution near Q${}_{\beta \beta }$ of ${}^{136}$Xe
• Demonstration of neutrinoless double beta decay searches in gaseous xenon with NEXT
• Measurement of the ${}^{136}$Xe two-neutrino double beta decay half-life via direct background subtraction in NEXT
• Radiogenic backgrounds in the NEXT double beta decay experiment
• Calibration of the NEXT-White detector using ${}^{83m}\mathrm{Kr}$ decays
• Characterisation of NEXT-DEMO using xenon K${}_{\alpha }$ X-rays
• Demonstration of the event identification capabilities of the NEXT-White detector
• First Results on the Search for Lepton Number Violating Neutrinoless Double Beta Decay with the LEGEND-200 Experiment
• Boosting background suppression in the NEXT experiment through Richardson-Lucy deconvolution
• Electron drift properties in high pressure gaseous xenon
• The NEXT-100 Detector
• Measurement of radon-induced backgrounds in the NEXT double beta decay experiment
• The electronics of the energy plane of the NEXT-White detector