171000 20260430151736.0 doi 10.1016/j.nima.2026.171585 sideral 149027 ART-2026-149027 eng Antolín, I. Axion–nucleon sensitivity using ultra-low background Micromegas detectors for the International Axion Observatory 2026 The International Axion Observatory (IAXO) aims to detect ultra-light bosonic dark matter candidates by combining strong magnetic fields, X-ray optics, and ultra-low background detectors. This work investigates the efficiency and sensitivity of various Micromegas detector configurations within IAXO, with a particular focus on the challenging axion–nucleon coupling channel. Through detailed simulations, we evaluate the intrinsic efficiency of the IAXO-D1 prototype, exploring both conventional argon-isobutane gas mixtures and a custom blend composed of 48.85% xenon, 48.85% neon, and 2.3% isobutane, under different pressure conditions. Detector responses are studied across a range of axion spectra. To support this analysis, a dedicated simulation framework was developed by integrating the Rare Event Searches Toolkit (REST) with Garfield++, Magboltz, and Geant4. The results highlight that Micromegas detectors operated with the xenon–neon-based gas mixture exhibit a marked improvement in performance compared to the nominal IAXO-D1 baseline configuration, with a signal-to-noise ratio enhancement of up to a factor of 3.7 in the case of axion–nucleon coupling sensitivity. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/AEI/PID2019-108122GB-C31 info:eu-repo/grantAgreement/ES/AEI/PID2022-137268NB-C51 info:eu-repo/grantAgreement/EC/H2020/802836/EU/Axions and relatives across different mass scales/AxScale This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 802836-AxScale info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Castel, J.F. Universidad de Zaragoza (orcid)0000-0003-3532-7540 Dafni, T. Universidad de Zaragoza (orcid)0000-0002-8921-910X Ferrer-Ribas, E. Galán, J. (orcid)0000-0001-7529-9834 Huerva, A. García Irastorza, I. Universidad de Zaragoza (orcid)0000-0003-1163-1687 Luzón, G. Universidad de Zaragoza (orcid)0000-0002-5352-1884 Margalejo, C. Universidad de Zaragoza (orcid)0000-0001-6213-5590 Mirallas, H. (orcid)0000-0002-9951-8680 Obis, L. (orcid)0000-0002-7990-2060 Porrón, J. Puyuelo, M.J. Ruz, J. (orcid)0000-0002-3253-7027 Vogel, J.K. (orcid)0000-0002-5850-5517 0 X Universidad de Zaragoza Grupos de investigación G.I. Física Nuclear y As GIFNA 2004 390 Universidad de Zaragoza Dpto. Física Teórica Área Física Atóm.Molec.y Nucl. 1089 (2026), 171585 [11 pp.] Nucl. instrum. methods phys. res., Sect. A Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 0168-9002 2690267 http://zaguan.unizar.es/record/171000/files/texto_completo.pdf Versión publicada 2475345 http://zaguan.unizar.es/record/171000/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:171000 articulos driver 2026-04-30-13:58:46 ARTICLE