Frontiers in Physics (May 2024)

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

  • K. Altenmüller,
  • J. F. Castel,
  • S. Cebrián,
  • T. Dafni,
  • D. Díez-Ibañez,
  • A. Ezquerro,
  • E. Ferrer-Ribas,
  • J. Galan,
  • J. Galindo,
  • 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,
  • A. Quintana,
  • J. Ruz,
  • J. K. Vogel,
  • J. K. Vogel

DOI
https://doi.org/10.3389/fphy.2024.1384415
Journal volume & issue
Vol. 12

Abstract

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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 cosmic-ray induced neutron background. Over an effective time of 52 days, a background level of 8.6 × 10−7 counts keV−1 cm−2 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 counts keV−1 cm−2 s−1 are discussed.

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