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  • Open Access

Development of a novel tunable gradient permanent quadrupole magnet

Shaoxiang Dong*, Yimin Yang*, Bingshun Zhang, Yiyue Wang, and Guangyao Feng†

  • *These authors contributed equally to this work.
  • †Contact author: fenggy@ustc.edu.cn
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Phys. Rev. Accel. Beams 28, 122401 – Published 23 December, 2025

DOI: https://doi.org/10.1103/cwdp-rpfx

Abstract

Addressing the demands for compactness and tunability in magnet systems for fourth-generation light sources, this paper presents the design and development of a novel tunable permanent quadrupole magnet (PQM) prototype. The prototype achieves a maximum field gradient of 65  T/m and demonstrates a continuous tuning range of 39  T/m. Within the effective aperture, normalized multipole field components are maintained below 5×10−4. Experimental validation confirms that the prototype meets the engineering design requirements for the Hefei Advanced Light Facility. Compared to conventional electromagnetic quadrupoles, this PQM features a compact structure, with negligible power consumption and high magnetic field quality, representing a promising technology for advanced synchrotron radiation light sources and free-electron lasers.

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Phys. Rev. Accel. Beams 28, 122401– Published 23 December, 2025
  • Received 30 May 2025
  • Accepted 28 October 2025
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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.

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