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arXiv · 2403.06316

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

Abstract

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.

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K. Altenmüller, J. F. Castel, S. Cebrián, T. Dafni, D. Díez-Ibañez, A. Ezquerro, E. Ferrer-Ribas, J. Galan, J. Galindo, J. A. García, A. Giganon, C. Goblin, I. G. Irastorza, C. Loiseau, G. Luzón, X. F. Navick, C. Margalejo, H. Mirallas, L. Obis, A. Ortiz de Solórzano, T. Papaevangelou, O. Pérez, A. Quintana, J. Ruz, J. K. Vogel. 2024-03-10. Background discrimination with a Micromegas detector prototype and veto system for BabyIAXO. https://arxiv.org/abs/2403.06316

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