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
  • Open Access

Space charge effects on coupled-bunch instability in high-intensity proton rings

Kazuhito Ohmi1,2,3, Liangsheng Huang1, Hanyang Liu1, and Li Rao1

Phys. Rev. Accel. Beams 28, 070101 – Published 7 July, 2025

DOI: https://doi.org/10.1103/c876-vj6w

Abstract

High-intensity proton accelerators are utilized for neutron, neutrino, and hadron sources. Increasing the beam intensity is important for science that utilizes these particles. However, as beam intensity increases in these proton accelerators, beam instability has emerged as a limiting factor. Coupled-bunch instability, resulting from impedance with frequency components near or below the revolution frequency, stemming from the electrical resistance of beam chambers, ceramic chambers in rapid cycling synchrotrons, and kicker magnets, poses a significant challenge in these proton accelerators. The oscillation frequency of beams observed during operation with chromaticity is considerably higher than the impedance frequency. Space charge forces exhibit significant strength, with a tune shift exceeding 0.1 as an absolute value. In single-bunch behavior, space charge forces dominate, influencing the oscillation modes of instability. It is inevitable that the effect will extend to coupled-bunch modes. This paper provides a theoretical discussion on the coupled-bunch instability of beams subjected to intense space charge forces.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (15)

  1. S. Wang, Y. An, S. Fang et al., An overview of design for CSNS/RCS and beam transport, Sci. China: Phys., Mech. Astron. 54, 239 (2011).
  2. High-Intensity Proton Accelerator Project Team, Accelerator technical design report for high-intensity proton accelerator facility project, JAERI Report No. JAERI-Tech 2003-044 and KEK Report No. 2002-13.
  3. L. Huang, S. Wang, S. Xu, X. Liu, M. Huang, R. Liu, B. Tan, H. Liu, L. Rao, and Y. Han, Source of instability in the rapid cycling synchrotron of the China spallation neutron source, Eur. Phys. J. Plus 140, 71 (2025).
  4. Y. Shobuda, Y. H. Chin, N. Hayashi, Y. Irie, T. Takayanagi, T. Togashi, T. Toyama, K. Yamamoto, and M. Yamamoto, Reducing the beam impedance of the kicker at the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex, Phys. Rev. Accel. Beams 21, 061003 (2018).
  5. K. Ohmi and Y. Zhang, Effects of space charge force on the beam-beam mode coupling instability, Phys. Rev. Accel. Beams 27, 101001 (2024).
  6. M. Blaskiewicz, Fast head-tail instability with space charge, Phys. Rev. ST Accel. Beams 1, 044201 (1998).
  7. A. Burov, Head-tail mode for strong space charge, Phys. Rev. ST Accel. Beams 12, 044202 (2009).
  8. A. Macridin, A. Burov, E. Stern, J. Amundson, and P. Spentzouris, Simulation of transverse modes with their intrinsic Landau damping for bunched beams in the presence of space charge, Phys. Rev. ST Accel. Beams 18, 074401 (2015).
  9. V. Kornilov and O. Boine-Frankenheim, Head-tail instability and Landau damping in bunches with space charge, Phys. Rev. ST Accel. Beams 13, 114201 (2010).
  10. Y. H. Chin, A. W. Chao, and M. M. Blaskiewicz, Two particle model for studying the effects of space-charge force on strong head-tail instabilities, Phys. Rev. Accel. Beams 19, 014201 (2016).
  11. X. Buffat, E. Metral, E. Gottlob, C. Hogh, A. Oeftiger, and T. Pieloni, Description of beam instabilities in synchrotrons with wakefields and space charge forces using the criculant matrix model, Phys. Rev. Accel. Beams 24, 060101 (2021).
  12. Y. Shobuda, Y. H. Chin, P. K. Saha, H. Hotchi, H. Harada, Y. Irie, F. Tamura, N. Tani, T. Toyama, Y. Watanabe, and M. Yamamoto, Theoretical elucidation of space charge effects on the coupled-bunch instability at the 3 GeV rapid cycling synchrotron at the Japan Proton Accelerator Research Complex, Prog. Theor. Exp. Phys. 2017, 013G01 (2017).
  13. A. Burov, Coupled-beam and coupled-bunch instabilities, Phys. Rev. Accel. Beams 21, 114401 (2018).
  14. A. Chao, Physics of Collective Beam Instabilities in High Energy Accelerators (Wiley-Interscience Publication, New York, 1993).
  15. K. Ohmi, Y. Zhang, and C. Lin, Beam-beam mode coupling in collision with a crossing angle, Phys. Rev. Accel. Beams 26, 111001 (2023).

Outline

Information

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation