Axion–nucleon sensitivity using ultra-low background Micromegas detectors for the International Axion Observatory

Antolín, I. ; Castel, J.F. (Universidad de Zaragoza) ; Dafni, T. (Universidad de Zaragoza) ; Ferrer-Ribas, E. ; Galán, J. ; Huerva, A. ; García Irastorza, I. (Universidad de Zaragoza) ; Luzón, G. (Universidad de Zaragoza) ; Margalejo, C. (Universidad de Zaragoza) ; Mirallas, H. ; Obis, L. ; Porrón, J. ; Puyuelo, M.J. ; Ruz, J. ; Vogel, J.K.

Resumen: 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.

Idioma: Inglés

DOI: 10.1016/j.nima.2026.171585

Año: 2026

Publicado en: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1089 (2026), 171585 [11 pp.]
ISSN: 0168-9002

Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2019-108122GB-C31
Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2022-137268NB-C51
Financiación: info:eu-repo/grantAgreement/EC/H2020/802836/EU/Axions and relatives across different mass scales/AxScale

Tipo y forma: Article (Published version)

Área (Departamento): G.I. Física Nuclear y As GIFNA (Grupos de investigación)
Área (Departamento): Área Física Atóm.Molec.y Nucl. (Dpto. Física Teórica)