Author: Zhang, Y.
Paper Title Page
MOPGW051 Diffusion Map Analysis in High Energy Storage Ring Based e+/e Collider 203
SUSPFO074   use link to see paper's listing under its alternate paper code  
 
  • J. Wu, Q. Qin, Y. Zhang
    IHEP, Beijing, People’s Republic of China
  • J. Wu, Y. Zhang
    University of Chinese Academy of Sciences, Beijing, People’s Republic of China
 
  Funding: Project 11775238 supported by NSFC
In a very high energy e+/e storage ring collider, e.g. Circular Electron Positron Collider (CEPC), the dynamic aperture is limited by the strong synchrotron radiation especially in the vertical direction. Some tracking results also shows that the beam lifetime does not correspond well to the dynamic aperture. Here we develop a method called diffusion map analysis, aiming to describe the beam distribution diffusion in transverse amplitude space by tracking less turns. The diffusion may come from quantum fluctuation of SR, beamstrahlung effect and nonlinearity. Comparing cases with different configuration of sextupoles, the diffusion map analysis presents good consistency with beam lifetime that needs much more turns of tracking. Constraints based on the diffusion map is applied to our dynamic aperture optimization, which could help us achieve enough long beam lifetime.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW051  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPGW068 Crosstalk of Beam-Beam Effect and Longitudinal Impedance at CEPC 247
 
  • Y. Zhang, N. Wang, C.H. Yu
    IHEP, Beijing, People’s Republic of China
  • C.T. Lin
    University of Chinese Academy of Sciences, Beijing, People’s Republic of China
 
  Funding: Project 11775238 supported by NSFC
In conventional e+e storage ring colliders, we only use lengthend bunch length in beam-beam simulation instead of considering impedance directly. It is no problem since the longitudinal dynamics is not sensitive to beam-beam interaction. But it is different since the bunch will also be lengthend during beam-beam interaction by beamstrahlung effect. It is very natural and more self-consistent to consider the longitudinal impedance in the beam-beam simulation. The simulation shows that the working point region of stable collision is slightly shifted by the longitudinal impedance. It is found that the vertical coherent oscillation may decreases the beam-beam limit with impedance at some working point.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW068  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPMP012 Concepts of Longitudinally Polarized Electron and Positron Colliding Beams in the Circular Electron Positron Collider 445
 
  • Z. Duan, J. Gao, X.P. Li, D. Wang, Y. Wang, W.H. Xia, Q.J. Xu, C.H. Yu, Y. Zhang
    IHEP, Beijing, People’s Republic of China
 
  Funding: Work supported by National Key Research and Development Program of China (No.2018YFA0404300).
This paper reports some preliminary study into the imple- mentation of longitudinally polarized e+/e colliding beams in the Circular Electron Positron Collider, at a center of mass energy of 91 GeV as a Z factory and energies beyond.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP012  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB024 Beam-Gas and Beam-Thermal Photon Scattering in CEPC 626
 
  • S. Bai, J. Gao, H. Geng, D. Wang, Y. Wang, C.H. Yu, Y. Zhang
    IHEP, Beijing, People’s Republic of China
  • Y. Zhang
    University of Chinese Academy of Sciences, Beijing, People’s Republic of China
 
  The Circular Electron Positron Collider (CEPC) is a proposed Higgs factory with center of mass energy of 240 GeV to measure the properties of Higgs boson and test the standard model accurately. Beam loss background in detectors is an important topic at CEPC. Beam-Gas scattering (BG) and Beam-Thermal photon scattering (BTH), although not so serious as Radiative Bhabha scattering (RBB) and Beamstrahlung (BS), are also important components of the beam induced backgrounds at CEPC due to the beam lifetime. In this paper, we evaluated the beam-gas and beam-thermal photon scattering in simulation and designed collimators to suppress the radiation level on the machine and the detector.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB024  
About • paper received ※ 28 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEYPLM1 Status of Circular Electron-Positron Collider and Super Proton-Proton Collider 2244
 
  • C.H. Yu, S. Bai, X. Cui, J. Gao, H. Geng, D.J. Gong, D. Ji, Y.D. Liu, C. Meng, Q. Qin, J.Y. Tang, D. Wang, N. Wang, Y. Wang, Y. Wei, J.Y. Zhai, Y. Zhang, H.J. Zheng, Y.S. Zhu
    IHEP, Beijing, People’s Republic of China
 
  Circular electron-positron collider (CEPC) is a dedi-cated project proposed by China to research the Higgs boson. The collider ring provides e+ e collision at two interaction points (IP). The luminosity for the Higgs mode at the beam energy of 120GeV is 3*1034 cm-2s-1 at each IP while the synchrotron radiation (SR) power per beam is 30MW. Furthermore, CEPC is compatible with W and Z experiments, for which the beam energies are 80 GeV and 45.5 GeV respectively. The luminosity at the Z mode is higher than 1.7*1035 cm-2s-1 per IP. Top-up operation is available during the data taking of high energy physics. Super Proton-Proton Collider (SPPC) is envisioned to be an extremely powerful machine, with centre mass energy of 75 TeV, a nominal luminosity of 1.0*1035 cm-2s-1 per IP, and an integrated luminosity of 30 ab-1 assuming 2 interaction points and ten years of running. The status of CEPC and SPPC will be introduced in detail in this paper.  
slides icon Slides WEYPLM1 [11.814 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYPLM1  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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