Paper

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

Vogel, J K, Loiseau, C, Ferrer-Ribas, E, Ezquerro, A, Margalejo, C, Altenmüller, K, Galan, J, Luzón, G, Pérez, O, Galindo, J, Navick, X F, Obis, L, Ortiz de Solórzano, A, Papaevangelou, T, Dafni, T, Castel, J F, Ruz, J, García, J A, Díez-Ibañez, D, Cebrián, S, Irastorza, I G, Giganon, A, Quintana, A, Mirallas, H, Goblin, C

2024

Overview

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.

• Publisher: Cornell University Library, arXiv.org
• Subject: Multilayers / Prototypes / Sensors / X ray detectors