Paper

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

Esteve, R, Romeo, B, Álvarez, V, Toledo, J F, Valle, P R G, Cossío, F P, Pazos, A, Ayyad, Y, Martín-Albo, J, Jones, B J P, M Pérez Maneiro, Herrero-Gómez, P, Torelli, S, Silva, A L M, Hernando Morata, J A, Auria-Luna, F, Teixeira, J M R, Madigan, R, Carrete, C Hervés, Querol, M, Simón, A, Azevedo, C D R, Castillo, A, Molina-Canteras, J, Isabel, A F B, Novella, P, Renner, J, Coupe, R, García-Barrena, J, Saharia, P, Soleti, S R, Torrent, J, Almazán, H, Ayet, S, Cid, X, P A O C Silva, M del Barrio-Torregrosa, Monrabal, F, Yubero-Navarro, A, Gómez-Cadenas, J J, NEXT Collaboration, Henriques, C A O, Rogers, L, Herrero, V, Marques, A P, J M F dos Santos, Miller, R L, Tonnelé, C, Parmaksiz, I, Lebrun, P, Vanga, M, P Vázquez Cabaleiro, Teruel-Pardo, S, J F C A Veloso, Barcelon, J E, Mistry, K, Martínez, A, Ruiz-Chóliz, E, Sorel, M, Villamil, J D, Dietz, P, Seemann, M, Dey, E, Trettin, A, Freixa, Z, Monteiro, C M B, Felkai, R, Mora, F J, Ballester, F, Elorza, M, Arnquist, I J, Nygren, D R, Benlloch-Rodríguez, J M, Santos, F P, Shomroni, I, Marauri, A, Rivilla, I, Para, A, Ferrario, P, Brodoline, A, Conde, C A N, Cid, L, Fernandes, L M P, Pelegrin, J, Palacio,

2026

Overview

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.

• Publisher: Cornell University Library, arXiv.org
• Subject: Beta decay / Energy resolution / Krypton / Sensors / Xenon