We report details on the axion dark matter search experiment that uses the new technologies of a high-temperature superconducting (HTS) magnet and a Josephson parametric converter (JPC). An 18 T HTS solenoid magnet is developed for this experiment. The JPC is used as the first stage amplifier to achieve a near quantum-limited low-noise condition. A first dark-matter axion search was performed with the 18 T axion haloscope [Youngjae Lee et al., Phys. Rev. Lett. 128, 241805 (2022)]. The scan frequency range is from 4.7789 GHz to 4.8094 GHz (30.5 MHz range). No significant signal consistent with Galactic dark matter axion is observed. Our results set the best limit of the axion-photon-photon coupling ($g_{a\gamma \gamma }$) in the axion mass range of $19.764–19.890\mathrm{\mu }\mathrm{eV}$. Using the Bayesian method, the upper bounds of $g_{a\gamma \gamma }$ are set at $0.98\times |g_{a\gamma \gamma }^{\mathrm{KSVZ}}|$ ($1.11\times |g_{a\gamma \gamma }^{\mathrm{KSVZ}}|$) in the mass ranges of $19.764–19.771\mathrm{\mu }\mathrm{eV}$ (19.863 to $19.890\mathrm{\mu }\mathrm{eV}$), and at $1.76\times |g_{a\gamma \gamma }^{\mathrm{KSVZ}}|$ in the mass ranges of $19.772–19.863\mathrm{\mu }\mathrm{eV}$ with 90% confidence level, respectively. We report design, construction, operation, and data analysis of the 18 T axion haloscope experiment.

• Received 29 June 2022
• Accepted 17 October 2022

DOI:https://doi.org/10.1103/PhysRevD.106.092007

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

Published by the American Physical Society