Background discrimination with a Micromegas detector prototype and veto system for BabyIAXO

• Published in: arXiv.org
• Main Authors: Altenmüller, K, Castel, J F, Cebrián, S, Dafni, T, Díez-Ibañez, D, Ezquerro, A, Ferrer-Ribas, E, Galan, J, Galindo, J, García, J A, Giganon, A, Goblin, C, Irastorza, I G, Loiseau, C, Luzón, G, Navick, X F, Margalejo, C, Mirallas, H, Obis, L, Ortiz de Solórzano, A, Papaevangelou, T, Pérez, O, Quintana, A, Ruz, J, Vogel, J K
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 10.03.2024
• Subjects: Multilayers; Prototypes; Sensors; X ray detectors
• ISSN: 2331-8422

In this paper we present measurements performed with a Micromegas X-ray detector setup. The detector is a prototype in the context of the BabyIAXO helioscope, which is under construction to search for an emission of the hypothetical axion particle from the sun. An important component of such a helioscope is a low background X-ray detector with a high efficiency in the 1-10 keV energy range. The goal of the measurement was to study techniques for background discrimination. In addition to common techniques we used a multi-layer veto system designed to tag cosmogenic neutron background. Over an effective time of 52 days, a background level of \(8.6 \times 10^{-7}\,\text{counts keV}^{-1}\,\text{cm}^{-2} \, \text{s}^{-1}\) was reached in a laboratory at above ground level. This is the lowest background level achieved at surface level. In this paper we present the experimental setup, show simulations of the neutron-induced background, and demonstrate the process to identify background signals in the data. Finally, prospects to reach lower background levels down to \(10^{-7} \, \text{counts keV}^{-1} \, \text{cm}^{-2} \, \text{s}^{-1}\) will be discussed.