- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Accelerators and Beams

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Editors' Suggestion
  • Open Access

Development and high-current cw operation of 166.6 MHz high-power, higher-order-modes-damped β=1 quarter-wave SRF modules at the High Energy Photon Source

Pei Zhang1,2,*, Xinying Zhang1,2,†, Lin Guo1,2,‡, Qiang Ma1,2, Jin Dai1, Tongming Huang1,2, Hongjuan Zheng1,2, Fanbo Meng1, Zhenghui Mi1,2 et al.

Haiying Lin1, Qunyao Wang1,2, Dongbing Li1, Facheng Zhao1, Song Jin1,2, and Jian Li1,2

  • *Contact author: zhangpei@ihep.ac.cn
  • †Contact author: zhangxinying@ihep.ac.cn
  • ‡Present address: Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
PDF

Phys. Rev. Accel. Beams 29, 032002 – Published 16 March, 2026

DOI: https://doi.org/10.1103/b94g-qxr9

Abstract

The High Energy Photon Source (HEPS) is a recently commissioned 6 GeV fourth-generation synchrotron light source that utilizes a novel low-frequency superconducting radio-frequency (SRF) system. This system was designed to handle high beam power and achieve heavy damping of higher-order modes (HOMs) within strict spatial constraints. To meet these stringent requirements, we in-house developed and subsequently installed five β=1 quarter-wave SRF cavities operating at 166.6 MHz and 4.2 K with a compact envelope. The design incorporates an enlarged beampipe (505 mm in diameter) with a beamline absorber for effective HOM damping and adopts a single coaxial power coupler with on-cell coupling to handle a high continuous-wave power of 200 kW. Following rigorous cleaning and assembly protocols, the cryomodules demonstrated a peak electric field of 42  MV/m with negligible radiation and maintained a low dynamic heat load of 5 to 7 W at the operating voltage of 1.2 MV, results that significantly surpassed the design goals. Installed in Summer 2025, the cavities were instrumental in the successful acceleration of a 100 mA electron beam at HEPS in September 2025. This work represents the first successful implementation of superconducting quarter-wave cavities as the main accelerating system for a high-current storage ring, thereby extending the application limits of quarter-wave cavities from their conventional use in low-β accelerators to high-current electron storage rings and establishing a proven technology for future high-performance light sources.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (43)

  1. Y. Jiao, G. Xu, X. H. Cui, Z. Duan, Y. Y. Guo, P. He, D. H. Ji, J. Y. Li, X. Y. Li, C. Meng, Y. M. Peng, S. K. Tian, J. Q. Wang, N. Wang, Y. Y. Wei, H. S. Xu, F. Yan, C. H. Yu, Y. L. Zhao, and Q. Qin, The HEPS project, J. Synchrotron Radiat. 25, 1611 (2018).
  2. H. Xu et al., Equilibrium electron beam parameters of the High Energy Photon Source, Radiat. Detect. Technol. Methods 7, 279 (2023).
  3. H. Xu et al., First beam storage in the High Energy Photon Source storage ring, Radiat. Detect. Technol. Methods 9, 70 (2025).
  4. G. Xu, J. Chen, Z. Duan, and J. Qiu, On-axis beam accumulation enabled by phase adjustment of a double-frequency rf system for diffraction-limited storage rings, in Proceedings of the International Particle Accelerator Conference (IPAC-2016), Busan, Korea (JACoW, Geneva, Switzerland, 2016), Vol. 7, pp. 2032–2035, 10.18429/JACoW-IPAC2016-WEOAA02.
  5. L. Wang, J. Chen, H. Shi, G. Wang, N. Wang, Z. Duan, S. Tian, L. Huo, and P. Liu, A novel 5-cell strip-line kicker prototype for the HEPS on-axis injection system, Nucl. Instrum. Methods Phys. Res., Sect. A 992, 165040 (2021).
  6. Z. Duan et al., The swap-out injection scheme for the High Energy Photon Source, in Proceedings of the 9th International Particle Accelerator Conference (IPAC-2018), Vancouver, BC, Canada (JACoW, Geneva, Switzerland, 2018), Vol. 9, pp. 4178–4181, 10.18429/JACoW-IPAC2018-THPMF052.
  7. S. Jiang and G. Xu, On-axis injection scheme based on a triple-frequency rf system for diffraction-limited storage rings, Phys. Rev. Accel. Beams 21, 110701 (2018).
  8. P. Zhang, J. Dai, Z. Deng, L. Guo, T. Huang, D. Li, J. Li, Z. Li, H. Lin, Y. Luo, Q. Ma, F. Meng, Z. Mi, Q. Wang, H. Xu, X. Zhang, F. Zhao, and H. Zheng, Radio-frequency system of the High Energy Photon Source, Radiat. Detect. Technol. Methods 7, 159 (2023).
  9. H. Zheng, P. Zhang, F. Meng, T. Huang, H. Xu, X. Hao, X. Zhang, and L. Guo, Design evolution of the higher order-mode damping in 166.6-MHz quarter-wave β=1 superconducting cavities for HEPS, IEEE Trans. Appl. Supercond. 34, 1 (2024).
  10. I. Ben-Zvi and J. Brennan, The quarter wave resonator as a superconducting linac element, Nucl. Instrum. Methods Phys. Res. 212, 73 (1983).
  11. G. Bisoffi, Review of low beta structures [superconducting linear accelerators], IEEE Trans. Appl. Supercond. 9, 285 (1999).
  12. I. Ben-Zvi, Quarter wave resonators for β=1 accelerators, in Proceedings of the International Conference on RF Superconductivity (SRF2011), Chicago, IL (JACoW, Geneva, Switzerland, 2011), pp. 637–645.
  13. J. R. Harris, K. L. Ferguson, J. W. Lewellen, S. P. Niles, B. Rusnak, R. L. Swent, W. B. Colson, T. I. Smith, C. H. Boulware, T. L. Grimm, P. R. Cunningham, M. S. Curtin, D. C. Miccolis, D. J. Sox, and W. S. Graves, Design and operation of a superconducting quarter-wave electron gun, Phys. Rev. ST Accel. Beams 14, 053501 (2011).
  14. T. Xin et al., Design of a high-bunch-charge 112-MHz superconducting rf photoemission electron source, Rev. Sci. Instrum. 87, 093303 (2016).
  15. S. Verdú-Andrés et al., Design and vertical tests of double-quarter wave cavity prototypes for the high-luminosity LHC crab cavity system, Phys. Rev. Accel. Beams 21, 082002 (2018).
  16. D. Naik and I. Ben-Zvi, Suppressing multipacting in a 56 MHz quarter wave resonator, Phys. Rev. ST Accel. Beams 13, 052001 (2010).
  17. Q. Wu, S. Belomestnykh, I. Ben-Zvi, M. M. Blaskiewicz, T. Hayes, K. Mernick, F. Severino, K. Smith, and A. Zaltsman, Operation of the 56 MHz superconducting rf cavity in RHIC with higher order mode damper, Phys. Rev. Accel. Beams 22, 102001 (2019).
  18. X. Zhang, P. Zhang, Z. Li, J. Dai, X. Hao, Q. Ma, T. Huang, H. Lin, Z. Mi, Q. Wang, and F. Meng, The mechanical design, fabrication and tests of a 166.6 MHz quarter-wave β=1 proof-of-principle superconducting cavity for HEPS, Nucl. Instrum. Methods Phys. Res., Sect. A 947, 162770 (2019).
  19. L. Guo, P. Zhang, X. Zhang, J. Dai, Z. Mi, Q. Ma, and F. Meng, Development of a 166.6 MHz β=1 higher-order-mode-damped superconducting cavity, Rev. Sci. Instrum. 95, 074702 (2024).
  20. P. Zhang, X. Zhang, Z. Li, J. Dai, L. Guo, H. Lin, Q. Ma, T. Huang, Z. Mi, Q. Wang, and F. Meng, Development and vertical tests of a 166.6 MHz proof-of-principle superconducting quarter-wave β=1 cavity, Rev. Sci. Instrum. 90, 084705 (2019).
  21. L. Guo, P. Zhang, X. Zhang, H. Zheng, F. Meng, and Z. Li, Multipacting suppression of the HOM-damped 166.6-MHz β=1 quarter-wave superconducting cavities at HEPS, J. Instrum. 16, P11003 (2021).
  22. T. Huang, P. Zhang, Z. Li, X. Zhang, H. Lin, Q. Ma, F. Meng, and W. Pan, Development of a low-loss magnetic-coupling pickup for 166.6-MHz quarter-wave β=1 superconducting cavities, Nucl. Sci. Tech. 31, 87 (2020).
  23. X. Zhang, P. Zhang, Z. Li, Q. Wang, H. Lin, Z. Mi, Q. Ma, W. Pan, J. Dai, T. Huang, R. Han, R. Ge, L. Sun, F. Meng, and D. Li, Design and mechanical performance of a dressed 166.6 MHz β=1 proof-of-principle superconducting cavity in horizontal tests, IEEE Trans. Appl. Supercond. 30, 1 (2020).
  24. M. Fan, H. Liu, X. Wu, Y. Yang, S. Liu, A. Li, Y. Wang, B. Li, P. Qu, Q. Chen, and S. Wang, Development of the fundamental power coupler for 324 MHz superconducting cavities, Phys. Rev. Accel. Beams 26, 090401 (2023).
  25. T. Jiang, F. Bai, Y. He, Z. Lin, Y. Wan, R. Wang, Z. Wang, M. Xu, and S. Zhang, The development of a prototype fundamental power coupler for CiADS and HIAF half wave resonators, in Proceedings of the 20th International Conference on RF Superconductivity (SRF2021) (JACoW, Geneva, Switzerland, 2022), Vol. 20, pp. 295–298, 10.18429/JACoW-SRF2021-MOPCAV014.
  26. N. Solyak, B. Hanna, J. Helsper, S. Kazakov, D. Passarelli, and S. Wallon, Testing and processing of pre-production 325 MHz single spoke resonator power couplers for PIP-II project, in Proceedings of the 21st International Conference on RF Superconductivity (SRF2023) (JACoW, Geneva, Switzerland, 2023), Vol. 21, pp. 816–819, 10.18429/JACoW-SRF2023-WEPWB097.
  27. N. Bazin, S. Chel, G. Devanz, T. Ebisawa, H. Jenhani, G. Phillips, O. Piquet, D. Regidor, and F. Toral, Status of the IFMIF/EVEDA superconducting linac, in Proceedings of the International Conference on RF Superconductivity No. 19 (SRF2019) (JACoW, Geneva, Switzerland, 2019), pp. 735–741, 10.18429/JACoW-SRF2019-WETEA3.
  28. M. Kelly, Z. Conway, M. Kedzie, S. Kutsaev, J. Crisp, and L. Harle, Compact 4 kW variable rf power coupler for FRIB quarter-wave cavities, in Proceedings of the LINAC-2012, Tel-Aviv, Israel (JACoW, Geneva, Switzerland, 2012), pp. 678–680.
  29. J. Popielarski, P. Glennon, M. Hodek, and J. Wlodarczak, Development and testing of prototype fundamental power couplers for FRIB half wave resonators, in Proceedings of the SRF-2011, Chicago, IL (JACoW, Geneva, Switzerland, 2012), pp. 353–355.
  30. S. Noguchi, Couplers-experience at KEK, in Proceedings of the International Conference on RF Superconductivity (SRF1989), Tsukuba, Ibaraki, Japan (JACoW, Geneva, Switzerland, 1989), pp. 397–412.
  31. T. Huang, P. Zhang, Q. Ma, H. Lin, Q. Wang, W. Pan, F. Bing, K. Gu, and L. Guo, Development of fundamental power couplers for 166.6 MHz superconducting quarter-wave β=1 proof-of-principle cavities, Rev. Sci. Instrum. 91, 063301 (2020).
  32. T. Huang, P. Zhang, Z. Chang, Q. Ma, X. Zhang, Z. Li, R. Han, Q. Wang, H. Lin, J. Zhou, R. Ge, and W. Pan, High-power tests and solution to overheating at cavity-coupler interface of the 166.6-MHz β=1 superconducting quarter-wave resonator for HEPS, AIP Adv. 11, 045024 (2021).
  33. T. Huang, R. Guo, D. Li, H. Lin, J. Li, Y. Luo, Q. Ma, Q. Wang, and P. Zhang, The high-power test of CW 250 kW fundamental power couplers for HEPS 166.6 MHz superconducting quarter-wave β=1 cavity, in Proceedings of the 14th International Particle Accelerator Conference No. 14 (IPAC-2023) (JACoW, Geneva, Switzerland, 2023), Vol. 14, pp. 485–488, 10.18429/jacow-ipac2023-mopa185.
  34. X. Zhang, P. Zhang, Q. Ma, L. Guo, H. Zheng, F. Meng, Z. Mi, T. Huang, and J. Dai, Compact design of the 166.6 MHz superconducting cavity and its beamline elements for HEPS, Nucl. Instrum. Methods Phys. Res., Sect. A 1059, 168972 (2024).
  35. R. Han et al., Thermal performance analysis and cryogenic experimental measurements of the 166.6 MHz cavity cryomodule for the High Energy Photon Source, Nucl. Instrum. Methods Phys. Res., Sect. A 1070, 170000 (2025).
  36. R. Bosch, Instability analysis of an active higher-harmonic cavity, in Proceedings of the PAC-1997, Vancouver, BC, Canada (1997), pp. 862–864, 6V034, https://proceedings.jacow.org/pac97/papers/pdf/6V034.PDF.
  37. https://abci.kek.jp/abci.htm/.
  38. H. Padamsee, J. Knobloch, and T. Hays, RF Superconductivity for Accelerators, 2nd ed. (Wiley-VCH, Weinheim, Germany, 2008).
  39. L. Guo, Y. Chen, J. Li, Z. Li, Q. Ma, P. Zhang, X. Zhang, and H. Zheng, Design of the magnetic shielding for 166 MHz and 500 MHz superconducting rf cavities at High Energy Photon Source, in Proceedings of the 12th International Particle Accelerator Conference No. 12 (IPAC-2021), Virtual Edition, Brazil (JACoW, Geneva, Switzerland, 2021), pp. 2289–2291, 10.18429/JACoW-IPAC2021-TUPAB340.
  40. P. Zhang, A. D’Elia, W. Venturini Delsolaro, and K. Artoos, Frequency pre-tuning of the niobium-sputtered quarter-wave resonator for HIE-ISOLDE project at CERN, Nucl. Instrum. Methods Phys. Res., Sect. A 797, 101 (2015).
  41. L. Guo, J. Dai, P. Zhang, and X. Zhang, Frequency pre-tuning of the 166.6 MHz HOM-damped SRF cavities for HEPS, in Proceedings of the 14th International Particle Accelerator Conference No. 14 (IPAC-2023) (JACoW, Geneva, Switzerland, 2023), pp. 3090–3093, 10.18429/jacow-ipac2023-wepa192.
  42. H. Zheng, P. Zhang, Q. Ma, J. Dai, R. Han, T. Huang, F. Meng, Z. Mi, H. Lin, Q. Wang, D. Li, L. Sun, M. Sang, T. Zhao, S. Jin, R. Ye, R. Ge, and F. Zhao, Development and tests of the 499.8 MHz SRF cryomodules for HEPS, J. Instrum. 19, P10031 (2024).
  43. Z. Deng, P. Zhang, T. Huang, Q. Wang, H. Lin, J. Dai, Q. Ma, L. Xiao, and W. Pan, Development of an automatic control and analysis system for the conditioning of high-power couplers at IHEP, J. Instrum. 16, P07027 (2021).

Outline

Information

Phys. Rev. Accel. Beams 29, 032002– Published 16 March, 2026
  • Received 25 November 2025
  • Accepted 3 March 2026
Crossmark - Check for updates button
Creative Commons Logo

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.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation