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Polarization transmission in the Hadron Storage Ring of the Electron-Ion Collider

E. Hamwi1,2,*, J. P. Devlin1, and G. H. Hoffstaetter1,2

  • *Contact author: eh652@cornell.edu
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Phys. Rev. Accel. Beams 29, 073501 – Published 9 July, 2026

DOI: https://doi.org/10.1103/qjs6-l51f

Abstract

The successful operation of the future Electron-Ion Collider is contingent on maintaining high hadron beam polarization up to 275 GeV. The Hadron Storage Ring lattice, however, features a symmetry-breaking interaction region that excites strong, nonsystematic spin resonances, posing a significant threat to polarization preservation. This paper systematically investigates two complementary strategies to ensure high polarization transmission. The first method involves optimizing the vertical betatron phase advance between Siberian snakes to orchestrate a cancellation of depolarizing kicks across the ring. We demonstrate through simulations that both dynamic and fixed-optics solutions based on this principle can successfully preserve polarization through the strongest resonances. The second, more powerful approach involves optimizing the snake rotation axes to suppress resonance driving terms at their source. We revisit established symmetric configurations, such as the Lee-Courant schemes, and introduce a novel, highly symmetric “Doubly Lee-Courant” (DLC) scheme, which enforces a local π spin phase advance across every consecutive pair of snakes. Our analysis reveals a clear performance hierarchy, with the DLC configuration providing an exceptionally robust and energy-insensitive baseline for polarization preservation. We conclude that a hybrid strategy, using a DLC snake scheme as a symmetric foundation and betatron phase tuning for fine corrections, offers the most effective path forward for the EIC and future high-energy polarized-beam facilities.

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References (33)

  1. F. Willeke, Electron ion collider conceptual design report 2021, Tech. Rep. BNL, 2021, https://www.osti.gov/servlets/purl/1765663/.
  2. J. Berg , Lattice design for the hadron storage ring of the electron-ion collider, in Proceedings of the 14th International Particle Accelerator Conference, IPAC’23, Venice, Italy (JACoW, Geneva, Switzerland, 2023), pp. 903–905, 10.18429/JACoW-IPAC2023-MOPL156.
  3. V. Ranjbar, S. Y. Lee, M. Bai, E. Courant, and W. W. MacKay, Mapping out the full spin resonance structure of RHIC, in Proceedings of the Particle Accelerator Conference, PAC’01, Chicago (JACoW, Geneva, Switzerland, 2001), pp. 3177–3179, https://proceedings.jacow.org/p01/PAPERS/RPAH139.PDF.
  4. Y. S. Derbenev and A. M. Kondratenko, Acceleration of polarized particles to high energies in synchrotrons, in Proceedings of the 10th International Conference on High Energy Accelerators (1977), Vol. 10, p. 70, https://cds.cern.ch/record/472401.
  5. Y. S. Derbenev and A. M. Kondratenko, On the possibilities to obtain high-energy polarized particles in accelerators and storage rings, AIP Conf. Proc. 51, 292 (1979).
  6. E. D. Courant, Helical Siberian snakes, AIP Conf. Proc. 187, 1085 (1989).
  7. U. Wienands, Helical Siberian snakes using dipole magnets, Part. Accel. 36, 1 (1991), https://inis.iaea.org/records/jcx0f-bx675l.
  8. M. Syphers et al., Helical dipole magnets for polarized protons in RHIC, in Proceedings of the 1997 Particle Accelerator Conference (IEEE, New York, 1997), Vol. 3, pp. 3359–3361.
  9. H. Witte et al., The interaction region of the electron-ion collider EIC, in Proceedings of the International Particle Accelerator Conference, IPAC’21, Campinas, SP, Brazil (JACoW, Geneva, Switzerland, 2021), pp. 2574–2577, 10.18429/JACoW-IPAC2021-WEPAB002.
  10. J. Berg, R. Palmer, and H. Witte, Lattice design for the interaction region of the electron-ion collider, in Proceedings of the 14th International Particle Accelerator Conference, IPAC’23, Venice, Italy (JACoW, Geneva, Switzerland, 2023), pp. 909–912, 10.18429/JACoW-IPAC2023-MOPL158.
  11. G. H. Hoffstaetter, Optimal axes of Siberian snakes for polarized proton acceleration, Phys. Rev. ST Accel. Beams 7, 121001 (2004).
  12. G. H. Hoffstaetter, High Energy Polarized Proton Beams: A Modern View (Springer, New York, NY, 2006), Vol. 218.
  13. M. Vogt et al., Bounds on the maximum attainable equilibrium spin polarization of protons at high energy in HERA, Ph.D. dissertation, Technical Report No. DESY-THESIS-2000-054, Deutsches Elektronen-Synchrotron (DESY), Hamburg Germany, 2000.
  14. V. Bargmann, L. Michel, and V. L. Telegdi, Precession of the polarization of particles moving in a homogeneous electromagnetic field, Phys. Rev. Lett. 2, 435 (1959).
  15. M. Conte et al. Beam optics of the Dirac particle with anomalous magnetic moment, Part. Accel. 56, 99 (1996), https://inspirehep.net/literature/421158.
  16. K. Heinemann and D. P. Barber, The semiclassical Foldy-Wouthuysen transformation and the derivation of the Bloch equation for spin 1/2 polarized beams using Wigner functions, in 15th Advanced ICFA Beam Dynamics Workshop on Quantum Aspects of Beam Physics (1998), pp. 695–701, arXiv:physics/9901044.
  17. D. P. Barber, K. Heinemann, and G. Ripken, A canonical 8-dimensional formalism for classical spin-orbit motion in storage rings: I. A new pair of canonical spin variables, Z. Phys. C 64, 117 (1994).
  18. Y. S. Derbenev and A. Kondratenko, Polarization kinetics of particles in storage rings, Sov. Phys. JETP 37, 968 (1973), https://cds.cern.ch/record/406564.
  19. D. P. Barber, J. A. Ellison, and K. Heinemann, Quasiperiodic spin-orbit motion and spin tunes in storage rings, Phys. Rev. ST Accel. Beams 7, 124002 (2004).
  20. S. R. Mane, Exact solutions for the spin tune for model storage rings, Nucl. Instrum. Methods Phys. Res., Sect. A 480, 328 (2002).
  21. E. Forest, From Tracking Code to Analysis: Generalised Courant-Snyder Theory for Any Accelerator Model (Springer, Tokyo, 2016), 10.1007/978-4-431-55803-3.
  22. K. Hock et al., Simulations of polarized helions in the HSR, in Proceedings of the 15th International Particle Accelerator Conference, IPAC’24, Nashville, TN (JACoW Publishing, Geneva, Switzerland, 2024), pp. 1634–1636, 10.18429/JACoW-IPAC2024-TUPS05.
  23. E. Hamwi et al., Snake matching the EIC’s hadron storage ring, in Proceedings of the 15th International Particle Accelerator Conference, IPAC’24, Nashville, TN (JACoW, Geneva, Switzerland, 2024), pp. 1714–1717, 10.18429/JACoW-IPAC2024-TUPS33.
  24. E. Hamwi et al., Phase variation for snake matching in the EIC’s HSR, in Proceedings of the North American Particle Accelerator Conference, NAPAC2025, Sacramento, CA, USA (JACoW, Geneva, Switzerland, 2025), pp. 547–549, 10.18429/JACoW-NAPAC2025-TUP077.
  25. D. Sagan, bmad: A relativistic charged particle simulation library, Nucl. Instrum. Methods Phys. Res., Sect. A 558, 356 (2006), Proceedings of the 8th International Computational Accelerator Physics Conference.
  26. D. Sagan, A superconvergent algorithm for invariant spin field stroboscopic calculations, in Proceedings of the International Particle Accelerator Conference, IPAC’18, Vancouver, BC, Canada (JACoW, Geneva, Switzerland, 2018), pp. 145–148, 10.18429/JACoW-IPAC2018-MOPMF028.
  27. K. Yokoya, An algorithm for calculating the spin tune in circular accelerators, Technical Report No. DESY-99-006, DESY, arXiv:physics/9902068, 1999.
  28. M. Signorelli et al., Scibmad.jl (2025), https://github.com/bmad-sim/SciBmad.jl.
  29. M. Signorelli et al., Gtpsa.jl: A scibmad interface to the generalised truncated power series algebra library, in Proceedings of the North American Particle Accelerator Conference, NAPAC2025, Sacramento, CA, USA (JACoW, Geneva, Switzerland, 2025), pp. 145–148, 10.18429/JACoW-NAPAC2025-MOP044.
  30. A. Zelenski, G. Atoian, E. Beebe, S. Ikeda, T. Kanesue, S. Kondrashev, J. Maxwell, R. Milner, M. Musgrave, M. Okamura, A. A. Poblaguev, D. Raparia, J. Ritter, A. Sukhanov, and S. Trabocchi, Optically pumped polarized He++3 ion source development for RHIC/EIC, Nucl. Instrum. Methods Phys. Res., Sect. A 1055, 168494 (2023).
  31. H. Huang, F. Méot, V. Ptitsyn, V. Ranjbar, and T. Roser, Polarization preservation of polarized deuteron beams in the electron ion collider at brookhaven national laboratory, Phys. Rev. Accel. Beams 23, 021001 (2020).
  32. C. Peng, Development of polarized lithium sources for EICeic, in Proceedings of the 20th International Workshop on Polarized Sources, Targets, and Polarimetry, PSTP24 (Proceedings of Science, 2024), Vol. 472, https://indico.jlab.org/event/823/contributions/15100/attachments/11770/18360/Polarized_Lithium_Soures_Peng_v3.pdf.
  33. K. Hock, Snakes for the hadron storage ring, Technical Report No. BNL-229010-2025-TECH, BNL, 2025.

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Phys. Rev. Accel. Beams 29, 073501– Published 9 July, 2026
  • Received 22 September 2025
  • Accepted 15 April 2026
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