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Development of high gradient quadrupole magnets in HEPS storage ring

Mei Yang*, Yingshun Zhu*,†, Yafeng Wu, Xianjing Sun, Qing Li, Ran Liang, Chuang Shen, Siyu Chen, Yuandi Xu et al.

Shu Yang, Lei Wu*, Chunhua Li*, Yi Jiao*, and Fusan Chen*,‡

  • *Also at University of Chinese Academy of Sciences, Beijing, China.
  • †Contact author: yszhu@ihep.ac.cn
  • ‡Contact author: chenfs@ihep.ac.cn
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Phys. Rev. Accel. Beams 29, 083901 – Published 12 August, 2026

DOI: https://doi.org/10.1103/cg6l-1z6m

Abstract

The High Energy Photon Source is the first fourth-generation light source in China, featuring a hybrid multibend achromat lattice. This innovative design incorporates high gradient quadrupoles with an aperture of 26 mm, a gradient of about 80  T/m, and high-order field harmonics of less than 4×10−4. This paper details the optimized magnetic design, precise fabrication techniques, batch field measurements, and a method for field harmonic compensation utilizing a magic finger. A comparative analysis was conducted on nine types of the 480 pure quadrupole magnets that share the same cross section but differ in iron lengths. These variations include laminated or solid cores and closed or open yokes. The cross section, characterized by a narrow concave and convex pole contour, a tapered pole root, and saddle coils, is designed to mitigate magnetic saturation while enhancing the iron filling ratio. The impact of iron saturation on the transfer function and the evolution of current-dependent multipole fields has been systematically investigated, along with the effects of mechanical errors and inhomogeneities in the magnetic properties of the iron core on harmonics. We demonstrate a comprehensive engineering solution for high gradient small-aperture quadrupole magnets, which has been validated through mass production.

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References (22)

  1. Y. Jiao, G. Xu, X. Cui et al., The HEPS project, J. Synchrotron Radiat. 25, 1611 (2018).
  2. Y. Jiao, F. Chen, P. He, C. Li, J. Li, Q. Qin, H. Qu, J. Wan, J. Wang, and G. Xu, Modification and optimization of the storage ring lattice of the high energy photon source, Radiat. Detect. Technol. Methods 4, 415 (2020).
  3. Q. Li, F. Chen, C. Li, and M. Li, Design of the longitudinal-gradient dipole magnets for HEPS, Radiat. Detect. Technol. Methods 5, 1 (2021).
  4. M. Yang, C. Fusan, Y. Xu, Y. Wu, Y. Zhu, Z. Zhang, and B. Yin, Design and field performance of octupole magnet with skew quadrupole component in HEPS, IEEE Trans. Appl. Supercond. 32, 1 (2022).
  5. G. Le Bec, J. Chavanne, F. Villar, C. Benabderrahmane, S. Liuzzo, J.-F. Bouteille, L. Goirand, L. Farvacque, J.-C. Biasci, and P. Raimondi, Magnets for the ESRF diffraction limited light source project, IEEE Trans. Appl. Supercond. 26, 1 (2016).
  6. M. Abliz, M. Jaski, A. Jain, M. Borland, G. Decker, and J. Kerby, Magnetic crosstalk simulation between Q2 and L bend magnets of APS-U, Nucl. Instrum. Methods Phys. Res., Sect. A 913, 48 (2019).
  7. M. Johansson, B. Anderberg, and L.-J. Lindgren, Magnet design for a low-emittance storage ring, Synchrotron Radiat. 21, 884 (2014).
  8. Y. S. Zhu, F. S. Chen, M. Yang et al., Development of prototype high gradient small aperture quadrupole magnets for HEPS-TF, IEEE Trans. Appl. Supercond. 28, 4000205 (2018).
  9. N. Li, Y. Y. Guo, Y. Jiao et al., Modelling of the magnetic cross-talk effect of the HEPS storage ring, Nucl. Instrum. Methods Phys. Res., Sect. A 1089, 171604 (2026).
  10. M. Yang, W. Kang, C. Deng, X. Sun, L. Li, X. Wu, L. Gong, D. Cheng, Y. Zhu, and F. Chen, Magnetic fringe field interference between the quadrupole and corrector magnets in the CSNS/RCS, Nucl. Instrum. Methods Phys. Res. 847, 29 (2017).
  11. Opera simulation software (2020), https://www.3ds.com/products-services/simulia/products/opera/.
  12. Y. S. Zhu, F. S. Chen, and L. Wu, Multipole magnets and their magnetic field harmonics compensation method, China Patent No. ZL 2017106131363 (2019).
  13. M. Yang, F.-S. Chen, Y.-F. Wu, Z. Zhang, B.-G. Yin, B. Na, and Z.-J. Zhang, Development of short prototype of dual aperture quadrupole magnet for CEPC ring, Nucl. Sci. Tech. 34, 103 (2023).
  14. N. B. Song, Process review report of type I quadrupole magnets for HEPS storage ring, Internal Report, 2021.
  15. N. Li, D. H. Ji, and Y. Jiao, The influence of magic fingers in quadrupoles on beam dynamics, Internal Report, 2023.
  16. M. Yang, F. Chen, B. Yin, R. Liang, S. Li, and Y. Zhu, A rotating coil measurement system based on CMM for high-gradient small-aperture quadrupole in HEPS-TF, Radiat. Detect. Technol. Methods 5, 8 (2021).
  17. Fast Digital Integrator FDI 2056, https://www.metrolab.com/products/fast-digital-integrator-fdi2056.
  18. J. Tanabe, Iron Dominated Electromagnets: Design, Fabrication, Assembly and Measurements (World Scientific Publishing Co. Pte. Ltd,, Singapore, 2005).
  19. J. K. Animesh, Measurements of field quality using harmonic coils, US Particle Accelerator School on Superconducting Accelerator Magnets, 2001, Houston, Texas, USA.
  20. P. Arpaia, M. Buzio, G. Golluccio and L. Walckiers, In situ calibration of rotating sensor coils for magnet testing, Rev. Sci. Instrum. 83, 013306 (2012).
  21. P. Arpaia, O. Koster, G. Severino et al., Calibrating the sensing-coil radius by feed-down from a harmonic reference, Report No. CERN-ACC-2015-0073, 2014.
  22. M. Buzio, Magnetic measurement of small aperture quadrupoles at CERN, PSI, Villigen, 2010.

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Phys. Rev. Accel. Beams 29, 083901– Published 12 August, 2026
  • Received 25 September 2025
  • Accepted 16 July 2026
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