Study on time-dependent lattice to alleviate space charge effects in CSNS/RCS

  • X. Y. Zhang
  • L. H. Zhang
  • J. Y. TangEmail author
Original Paper



Tune shift and spread due to the space charge effects and collective instabilities in intense proton synchrotrons, such as the CSNS/RCS, a rapid cycling synchrotron at China Spallation Neutron Source, are the main causes of beam loss. Tune shift/spread is large when the beam kinetic energy is low and will cause particles to cross dangerous resonances, while they will gradually decay with the increase of kinetic energy.


An efficient way, which was verified in operational accelerators, is to tune the working point during different acceleration periods: injection, acceleration and extraction. With the newly added function of time-dependent lattice in the ORBIT code, one can simulate the physical performance with different tune patterns to find the best way to reduce beam loss.


The method to tune the working point by time-dependent lattice to weaken the crossing of dangerous resonances has been exploited, and implemented in the ORBIT code. It is the first of such try to apply the method in CSNS/RCS.


The results presented in this paper show that the time-dependent lattice method does help reduce beam loss in the injection and early acceleration.


Space charge effects Tune shift ORBIT code Time-dependent lattice Nonlinear magnets Resonance 



This work was supported jointly by the National Natural Science Foundation of China (Projects: 11575214), the National Key Research and Development Program of China (Project: 2016YFA0401600) and the CSNS Project. The authors would like to thank CSNS colleagues, A. Shishlo and J. Holmes from SNS, USA, for constructive discussions and comments.


  1. 1.
    J.Y. Tang, Rapid cycling synchrotrons and accumulator rings for high-intensity hadron beams, in REVIEW of Accelerator Science and Technology, vol. 6, ed. by A.W. Chao, W. Chou (World Scientific Publishing, Singapore, 2013)Google Scholar
  2. 2.
    I.S.K. Gardner, ISIS status report, in EPAC, Chilton, Didcot, Oxon (1994)Google Scholar
  3. 3.
    C.M. Warsop, Status and high intensity performance of ISIS, in Workshop on Space charge Physics in High Intensity Hadron Rings, Shelter Island, New York (1998)Google Scholar
  4. 4.
    J. Wei, S.X. Fang, S.N. Fu, China spallation neutron source accelerators: design, research, and development, in EPAC, Edinburgh (2006)Google Scholar
  5. 5.
    H.S. Chen, X.L. Wang, China’s first pulsed neutron source. Nat. Mater. 15, 689–691 (2016)ADSCrossRefGoogle Scholar
  6. 6.
    J. Wei, S.N. Fu, J.Y. Tang, J.Z. Tao, D.S. Wang, F.W. Wang, S. Wang, Chinese spallation neutron source—a overview of application prospects. Chin. Phys. C 33(11), 1033–1042 (2009)ADSCrossRefGoogle Scholar
  7. 7.
    J.D. Galambos, et al., ORBIT User Manual (1999)Google Scholar
  8. 8.
    S. Cousineau et al., Space-charge-sustained microbunch structure in the Los Alamos proton storage ring. Phys. Rev. Spec. Top. Accel. Beams 7, 094201 (2004)ADSCrossRefGoogle Scholar
  9. 9.
    J.A. Holmes, et al., High intensity effects in the SNS accumulator ring, in Proceedings of Hadron Beam, Nashville, Tennessee, USA (2008)Google Scholar
  10. 10.
    Y. Alexahin, et al., Effects of space charge and magnet nonlinearities on beam dynamics in the FermiLab booster, in Proceedings of PAC07 (2007)Google Scholar
  11. 11.
    C.M. Warsop, et al., Simulation and measurement of half integer resonance in coasting beams in the ISIS ring, in HB (2012)Google Scholar
  12. 12.
    J. Qiu et al., Studies of transverse phase space painting for the CSNS RCS injection. High Energy Phys. Nuclear Phys. 31(10), 942–946 (2007)Google Scholar
  13. 13.
    J.F. Chen, X.Y. Zhang, J.Y. Tang, Dual-harmonic acceleration studies at CSNS RCS, in Proceedings of HB2012, Beijing, China (2012)Google Scholar
  14. 14.
    Y. Zou et al., Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron. Nucl. Instr. Methods A737, 56–64 (2014)ADSCrossRefGoogle Scholar
  15. 15.
    R.W. Hockney, J.W. Eastwood, Computer Simulation Using Particles (IOP Publishing Ltd, Bristol, 1988)zbMATHGoogle Scholar
  16. 16.
    X.Y. Zhang, ORBIT development and beam dynamics study on time dependent lattice at CSNS/RCS, PhD thesis, Institute of High Energy Physics, CAS (2016) (in Chinese) Google Scholar
  17. 17.
    M.Y. Huang et al., Effects of injection beam parameters and foil scattering for CSNS/RCS. Chin. Phys. C 37(6), 067001 (2013)ADSCrossRefGoogle Scholar

Copyright information

© Institute of High Energy Physics, Chinese Academy of Sciences; Nuclear Electronics and Nuclear Detection Society and Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  1. 1.Institute of High Energy PhysicsChinese Academy of SciencesBeijingChina
  2. 2.University of Chinese Academy of SciencesBeijingChina

Personalised recommendations