Abstract
Purpose
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.
Methods
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.
Results
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.
Conclusions
The results presented in this paper show that the time-dependent lattice method does help reduce beam loss in the injection and early acceleration.
Similar content being viewed by others
References
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)
I.S.K. Gardner, ISIS status report, in EPAC, Chilton, Didcot, Oxon (1994)
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)
J. Wei, S.X. Fang, S.N. Fu, China spallation neutron source accelerators: design, research, and development, in EPAC, Edinburgh (2006)
H.S. Chen, X.L. Wang, China’s first pulsed neutron source. Nat. Mater. 15, 689–691 (2016)
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)
J.D. Galambos, et al., ORBIT User Manual (1999)
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)
J.A. Holmes, et al., High intensity effects in the SNS accumulator ring, in Proceedings of Hadron Beam, Nashville, Tennessee, USA (2008)
Y. Alexahin, et al., Effects of space charge and magnet nonlinearities on beam dynamics in the FermiLab booster, in Proceedings of PAC07 (2007)
C.M. Warsop, et al., Simulation and measurement of half integer resonance in coasting beams in the ISIS ring, in HB (2012)
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)
J.F. Chen, X.Y. Zhang, J.Y. Tang, Dual-harmonic acceleration studies at CSNS RCS, in Proceedings of HB2012, Beijing, China (2012)
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)
R.W. Hockney, J.W. Eastwood, Computer Simulation Using Particles (IOP Publishing Ltd, Bristol, 1988)
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)
M.Y. Huang et al., Effects of injection beam parameters and foil scattering for CSNS/RCS. Chin. Phys. C 37(6), 067001 (2013)
Acknowledgements
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.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhang, X.Y., Zhang, L.H. & Tang, J.Y. Study on time-dependent lattice to alleviate space charge effects in CSNS/RCS. Radiat Detect Technol Methods 3, 8 (2019). https://doi.org/10.1007/s41605-018-0084-9
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/s41605-018-0084-9