eeFACT2022 - List of Authors (Zhang, Y.)

Paper	Title	Page
TUYAT0104	CEPC Booster Lattice Design	61
	D. Wang, X. Cui, J. Gao, D. Ji, M. Li, Y.D. Liu, C. Meng, Y.M. Peng, C.H. Yu, J.Y. Zhai, Y. Zhang IHEP, Beijing, People’s Republic of China
	The CEPC booster provides electron and positron beams to the collider at different energies. The newest booster design is consistent with the TDR higher luminosity goals for four energy modes. The emittance of booster is reduced significantly in order to match the lower emittance of collider in TDR. Both FODO structure and TME structure was studied for booster design. A lot of efforts are made to overcome the difficulty of error sensitivity for the booster and hence the dynamic aperture with errors can fulfill the requirements at all energy modes. Also, the combined magnets scheme (B+S) are proposed to minimize the cost for magnets and power supplies. The design status of CEPC booster in TDR including parameters, optics and dynamic aperture is discussed in this paper.
	Slides TUYAT0104 [10.620 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-TUYAT0104
About •	Received ※ 03 November 2022 — Revised ※ 02 February 2023 — Accepted ※ 08 February 2023 — Issue date ※ 17 February 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXAT0101	Beam-beam Interaction in SuperKEKB: Simulations and Experimental Results	114
	D. Zhou, Y. Funakoshi, K. Ohmi, Y. Ohnishi KEK, Ibaraki, Japan Y. Zhang IHEP, Beijing, People’s Republic of China
	The beam-beam interaction is one of the most critical factors determining the luminosity performance of SuperKEKB. Simulations and experimental results from SuperKEKB have shown that a complete understanding of the beam-beam effects demands reliable models of 1) the nonlinear beam-beam interaction at the interaction point, 2) the one-turn lattice transfer map with machine imperfections, and 3) other intensity-dependent collective effects. The interplay of these factors makes it difficult to predict the luminosity performance of SuperKEKB via simulations. This paper continues the authors’ previous work* to discuss the beam-beam effects on luminosity in SuperKEKB. * D. Zhou, Y. Funakoshi, K. Ohmi, Y. Ohnishi, and Y. Zhang, Simulations and Measurements of Luminosity at SuperKEKB, in Proc. IPAC’22, Bangkok, Thailand, Jun. 2022, pp. 2011-2014.
	Slides WEXAT0101 [8.284 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-WEXAT0101
About •	Received ※ 26 November 2022 — Revised ※ 06 February 2023 — Accepted ※ 08 February 2023 — Issue date ※ 11 February 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXAT0104	Beam-beam Simulations including Coupling Impedance
	Y. Zhang, N. Wang IHEP, Beijing, People’s Republic of China M. Migliorati Sapienza University of Rome, Rome, Italy K. Ohmi, D. Zhou KEK, Ibaraki, Japan M. Zobov LNF-INFN, Frascati, Italy
	The design performance of future e⁺e⁻ ring colliders has been pushed to new extreme based on the crab-waist scheme. The new found coherent head-tail instability (X-Z instability) may induce the horizontal beam size blowup and reduce the machine performance. The longitudinal coupling impedance would distort the phase space: lengthen the bunch and bring incoherent synchrotron tune spread. The simulation study has found the clear influence of longitudinal impedance on the X-Z instability in both CEPC and FCCee. With the evolvement of future machine design process, the transverse impedance has also been included. The results show that a vertical beam-beam TMCI-like instability may be induced when the impedance is considered. It is first found in e⁺e⁻ colliders. Some similar study at SuperKEKB will also be presented. It could be expected or concluded that different effect would couple and determine the final performance together in present and future high performance crab-waist colliders. Separate effect study seems not enough to evaluate and predict the machine performance/stability.
	Slides WEXAT0104 [3.976 MB]
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYAT0101	Collective Effects Studies for CEPC	141
	N. Wang, C.T. Lin, Y.D. Liu, S.K. Tian, H.S. Xu, Y. Zhang IHEP, Beijing, People’s Republic of China
	The impedance model of the CEPC storage ring is updated according to the development of the vacuum components based on the circular beam pipe. With the impedance model, the single bunch and coupled bunch instabilities for different operation scenarios are investigated. Particularly, the key instability issues driven by the beam coupling impedance in the Z operation mode are discussed. The influence of the longitudinal impedance on the transverse mode coupling instability is analyzed both numerically and analytically. In addition, trapped ions can induce bunch centroid oscillation and emittance growth. The possibility of ion trapping and fast beam ion instability in the CEPC storage ring are also investigated.
	Slides WEYAT0101 [2.856 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-WEYAT0101
About •	Received ※ 30 November 2022 — Revised ※ 03 February 2023 — Accepted ※ 08 February 2023 — Issue date ※ 09 February 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEZAS0104	Commissioning of the Top-up Injection in the Collision Operation of BEPCII
	C.H. Yu, W.B. Liu, X.T. Wu, J. Xing, G.L. Xu, Y. Zhang IHEP, Beijing, People’s Republic of China
	BEPCII is designed not only for synchrotron radiation light source but also a collider. Topup operation for the synchrotron radiation facility has been realized in 2015. In order to improve the integral luminosity during the data taking of high energy physics, BEPCII began the dedicated upgrade to realize topup operation for the collider from the beginning of 2017. The modification of hardware devices have been finished at the end of 2019. The commissioning of the topup injection in the collision operation of BEPCII will be introduced in detail in this paper.
	Slides WEZAS0104 [6.606 MB]
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Paper

Title

Page

CEPC Booster Lattice Design

61

D. Wang, X. Cui, J. Gao, D. Ji, M. Li, Y.D. Liu, C. Meng, Y.M. Peng, C.H. Yu, J.Y. Zhai, Y. Zhang
IHEP, Beijing, People’s Republic of China

The CEPC booster provides electron and positron beams to the collider at different energies. The newest booster design is consistent with the TDR higher luminosity goals for four energy modes. The emittance of booster is reduced significantly in order to match the lower emittance of collider in TDR. Both FODO structure and TME structure was studied for booster design. A lot of efforts are made to overcome the difficulty of error sensitivity for the booster and hence the dynamic aperture with errors can fulfill the requirements at all energy modes. Also, the combined magnets scheme (B+S) are proposed to minimize the cost for magnets and power supplies. The design status of CEPC booster in TDR including parameters, optics and dynamic aperture is discussed in this paper.

Slides TUYAT0104 [10.620 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-TUYAT0104

About •

Received ※ 03 November 2022 — Revised ※ 02 February 2023 — Accepted ※ 08 February 2023 — Issue date ※ 17 February 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXAT0101

Beam-beam Interaction in SuperKEKB: Simulations and Experimental Results

114

D. Zhou, Y. Funakoshi, K. Ohmi, Y. Ohnishi
KEK, Ibaraki, Japan
Y. Zhang
IHEP, Beijing, People’s Republic of China

The beam-beam interaction is one of the most critical factors determining the luminosity performance of SuperKEKB. Simulations and experimental results from SuperKEKB have shown that a complete understanding of the beam-beam effects demands reliable models of 1) the nonlinear beam-beam interaction at the interaction point, 2) the one-turn lattice transfer map with machine imperfections, and 3) other intensity-dependent collective effects. The interplay of these factors makes it difficult to predict the luminosity performance of SuperKEKB via simulations. This paper continues the authors’ previous work* to discuss the beam-beam effects on luminosity in SuperKEKB.
* D. Zhou, Y. Funakoshi, K. Ohmi, Y. Ohnishi, and Y. Zhang, Simulations and Measurements of Luminosity at SuperKEKB, in Proc. IPAC’22, Bangkok, Thailand, Jun. 2022, pp. 2011-2014.

Slides WEXAT0101 [8.284 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-WEXAT0101

About •

Received ※ 26 November 2022 — Revised ※ 06 February 2023 — Accepted ※ 08 February 2023 — Issue date ※ 11 February 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEXAT0104

Beam-beam Simulations including Coupling Impedance

Y. Zhang, N. Wang
IHEP, Beijing, People’s Republic of China
M. Migliorati
Sapienza University of Rome, Rome, Italy
K. Ohmi, D. Zhou
KEK, Ibaraki, Japan
M. Zobov
LNF-INFN, Frascati, Italy

The design performance of future e⁺e⁻ ring colliders has been pushed to new extreme based on the crab-waist scheme. The new found coherent head-tail instability (X-Z instability) may induce the horizontal beam size blowup and reduce the machine performance. The longitudinal coupling impedance would distort the phase space: lengthen the bunch and bring incoherent synchrotron tune spread. The simulation study has found the clear influence of longitudinal impedance on the X-Z instability in both CEPC and FCCee. With the evolvement of future machine design process, the transverse impedance has also been included. The results show that a vertical beam-beam TMCI-like instability may be induced when the impedance is considered. It is first found in e⁺e⁻ colliders. Some similar study at SuperKEKB will also be presented. It could be expected or concluded that different effect would couple and determine the final performance together in present and future high performance crab-waist colliders. Separate effect study seems not enough to evaluate and predict the machine performance/stability.

Slides WEXAT0104 [3.976 MB]

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYAT0101

Collective Effects Studies for CEPC

141

N. Wang, C.T. Lin, Y.D. Liu, S.K. Tian, H.S. Xu, Y. Zhang
IHEP, Beijing, People’s Republic of China

The impedance model of the CEPC storage ring is updated according to the development of the vacuum components based on the circular beam pipe. With the impedance model, the single bunch and coupled bunch instabilities for different operation scenarios are investigated. Particularly, the key instability issues driven by the beam coupling impedance in the Z operation mode are discussed. The influence of the longitudinal impedance on the transverse mode coupling instability is analyzed both numerically and analytically. In addition, trapped ions can induce bunch centroid oscillation and emittance growth. The possibility of ion trapping and fast beam ion instability in the CEPC storage ring are also investigated.

Slides WEYAT0101 [2.856 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-eeFACT2022-WEYAT0101

About •

Received ※ 30 November 2022 — Revised ※ 03 February 2023 — Accepted ※ 08 February 2023 — Issue date ※ 09 February 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEZAS0104

Commissioning of the Top-up Injection in the Collision Operation of BEPCII

C.H. Yu, W.B. Liu, X.T. Wu, J. Xing, G.L. Xu, Y. Zhang
IHEP, Beijing, People’s Republic of China

BEPCII is designed not only for synchrotron radiation light source but also a collider. Topup operation for the synchrotron radiation facility has been realized in 2015. In order to improve the integral luminosity during the data taking of high energy physics, BEPCII began the dedicated upgrade to realize topup operation for the collider from the beginning of 2017. The modification of hardware devices have been finished at the end of 2019. The commissioning of the topup injection in the collision operation of BEPCII will be introduced in detail in this paper.

Slides WEZAS0104 [6.606 MB]

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)