IPAC2021 - List of Authors (Wang, N.)

Paper	Title	Page
MOXC01	Combined Effect of Beam-Beam Interaction and Beam Coupling Impedance in Future Circular Colliders	25
	Y. Zhang, N. Wang IHEP, Beijing, People’s Republic of China E. Carideo CERN, Geneva, Switzerland M. Migliorati SBAI, Roma, Italy M. Zobov INFN/LNF, Frascati, Italy
	Funding: This work is supported by National Key Programme for S&T Research and Development, China (Grant No. 2016YFA0400400), National Natural Science Foundation of China (No. 11775238, No. 11775239). The future large scale electron-positron colliders, such as FCC-ee in Europe and CEPC in China, will rely on the crab waist collision scheme with a large Piwinski angle. Differently from the past generation colliders both luminosity and beam-beam tune shifts depend on the bunch length in such a collision scheme. In addition, for the future circular colliders with extreme beam parameters in collision several new effects become important such as beamstrahlung, coherent X-Z instability and 3D flip-flop. For all these effects the longitudinal beam dynamics plays an essential role and should be taken into account for the collider luminosity optimization. In this paper we discuss an impact of the longitudinal beam coupling impedance on the collider performance.
	Slides MOXC01 [2.269 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOXC01
About •	paper received ※ 17 May 2021 paper accepted ※ 27 July 2021 issue date ※ 17 August 2021
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MOPAB053	Progress of Lattice Design and Physics Studies on the High Energy Photon Source	229
	Y. Jiao, Y. Bai, X. Cui, C.C. Du, Z. Duan, Y.Y. Guo, P. He, X.Y. Huang, D. Ji, H.F. Ji, S.C. Jiang, B. Li, C. Li, J.Y. Li, N. Li, X.Y. Li, P.F. Liang, C. Meng, W.M. Pan, Y.M. Peng, Q. Qin, H. Qu, S.K. Tian, J. Wan, B. Wang, J.Q. Wang, N. Wang, Y. Wei, G. Xu, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao IHEP, Beijing, People’s Republic of China X.H. Lu IHEP CSNS, Guangdong Province, People’s Republic of China
	Funding: Work supported by High Energy Photon Source (HEPS), a major national science and technology infrastructure and NSFC (11922512) The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. The HEPS construction started in mid-2019. While the physics design has been basically determined, modifications on the HEPS accelerator physics design have been made since 2019, in order to deal with challenges emerging from the technical and engineering designs. In this paper, we will introduce the new storage ring lattice and injector design, and also present updated results of related physics issues, including impedance and collective effects, lattice calibration, insertion device effects, injection design studies, etc.
	Poster MOPAB053 [0.699 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB053
About •	paper received ※ 10 May 2021 paper accepted ※ 24 May 2021 issue date ※ 17 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB102	CSR Impedance in HEPS Storage Ring	379
	H.S. Xu, X.Y. Li, N. Wang IHEP, Beijing, People’s Republic of China
	High Energy Photon Source (HEPS) is under construction in Beijing, China. The relatively complete impedance model has been built up based on the element-by-element impedance calculation. However, Coherent Synchrotron Radiation (CSR) impedance, which might affect the longitudinal performance of the beam, was not included in the impedance model of the HEPS storage ring in the preliminary design stage. For completeness, we would like to take the CSR impedance into consideration. The most important contributions to the total CSR impedance come from the bending magnets and insertion devices. We therefore calculate the CSR impedance from both above mentioned elements in HEPS storage ring. The influence of the CSR impedance on the microwave instability threshold is studied and presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB102
About •	paper received ※ 17 May 2021 paper accepted ※ 18 June 2021 issue date ※ 27 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB090	Higher Order Mode Damping for 166 MHz and 500 MHz Superconducting RF Cavities at High Energy Photon Source	2798
	H.J. Zheng, Z.Q. Li, F. Meng, N. Wang, H.S. Xu, P. Zhang, X.Y. Zhang IHEP, Beijing, People’s Republic of China
	Funding: This work was supported in part by High Energy Photon Source, in part by the National Natural Science Foundation of China under Grant No. 11905232. Superconducting rf cavities have been chosen for High Energy Photon Source, a 6 GeV diffraction-limited synchrotron light source under construction in Beijing. The main accelerating cavity adopted a quarter-wave β=1 structure operating at 166 MHz while the third harmonic cavity utilized the single-cell elliptical geometry at 500 MHz for the storage ring. The high beam current (200 mA) requires a strong damping of higher order modes (HOMs) excited in the superconducting cavities. To meet the beam stability requirements, enlarged beam pipes with a diameter of 505 mm for the 166 MHz cavity and 300 mm for the 500 MHz cavity were chosen to allow all HOMs to propagate along the beam tubes and to be damped by beam-line absorbers. This paper presents the HOM damping scheme and the cavity impedance analysis results. In addition, power losses due to HOMs were also evaluated for various operation modes (high charge and high luminosity) of the HEPS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB090
About •	paper received ※ 17 May 2021 paper accepted ※ 22 June 2021 issue date ※ 20 August 2021
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WEPAB222	Impedance Evaluation of Masks in the HEPS Storage Ring	3145
	N. Wang, S.K. Tian, J.Q. Wang IHEP, Beijing, People’s Republic of China J.Q. Wang University of Chinese Academy of Sciences, Beijing, People’s Republic of China
	Masks are commonly used in photon light sources to protect sensitive elements from synchrotron radiations. In the ultra-low emittance rings, small aperture vacuum chambers are adopted in order to reach the very high gradient in the quadrupoles, while many masks are required due to the high radiation power density. Therefore, the impedance of the masks becomes one of the dominant contributors to the impedance budget. In this paper, the impedance is evaluated among different mask designs. Meanwhile, the impedance cross-talk between adjacent masks is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB222
About •	paper received ※ 18 May 2021 paper accepted ※ 06 July 2021 issue date ※ 15 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Combined Effect of Beam-Beam Interaction and Beam Coupling Impedance in Future Circular Colliders

25

Y. Zhang, N. Wang
IHEP, Beijing, People’s Republic of China
E. Carideo
CERN, Geneva, Switzerland
M. Migliorati
SBAI, Roma, Italy
M. Zobov
INFN/LNF, Frascati, Italy

Funding: This work is supported by National Key Programme for S&T Research and Development, China (Grant No. 2016YFA0400400), National Natural Science Foundation of China (No. 11775238, No. 11775239).
The future large scale electron-positron colliders, such as FCC-ee in Europe and CEPC in China, will rely on the crab waist collision scheme with a large Piwinski angle. Differently from the past generation colliders both luminosity and beam-beam tune shifts depend on the bunch length in such a collision scheme. In addition, for the future circular colliders with extreme beam parameters in collision several new effects become important such as beamstrahlung, coherent X-Z instability and 3D flip-flop. For all these effects the longitudinal beam dynamics plays an essential role and should be taken into account for the collider luminosity optimization. In this paper we discuss an impact of the longitudinal beam coupling impedance on the collider performance.

Slides MOXC01 [2.269 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOXC01

About •

paper received ※ 17 May 2021 paper accepted ※ 27 July 2021 issue date ※ 17 August 2021

Export •

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

MOPAB053

Progress of Lattice Design and Physics Studies on the High Energy Photon Source

229

Y. Jiao, Y. Bai, X. Cui, C.C. Du, Z. Duan, Y.Y. Guo, P. He, X.Y. Huang, D. Ji, H.F. Ji, S.C. Jiang, B. Li, C. Li, J.Y. Li, N. Li, X.Y. Li, P.F. Liang, C. Meng, W.M. Pan, Y.M. Peng, Q. Qin, H. Qu, S.K. Tian, J. Wan, B. Wang, J.Q. Wang, N. Wang, Y. Wei, G. Xu, H.S. Xu, F. Yan, C.H. Yu, Y.L. Zhao
IHEP, Beijing, People’s Republic of China
X.H. Lu
IHEP CSNS, Guangdong Province, People’s Republic of China

Funding: Work supported by High Energy Photon Source (HEPS), a major national science and technology infrastructure and NSFC (11922512)
The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. The HEPS construction started in mid-2019. While the physics design has been basically determined, modifications on the HEPS accelerator physics design have been made since 2019, in order to deal with challenges emerging from the technical and engineering designs. In this paper, we will introduce the new storage ring lattice and injector design, and also present updated results of related physics issues, including impedance and collective effects, lattice calibration, insertion device effects, injection design studies, etc.

Poster MOPAB053 [0.699 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB053

About •

paper received ※ 10 May 2021 paper accepted ※ 24 May 2021 issue date ※ 17 August 2021

Export •

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

MOPAB102

CSR Impedance in HEPS Storage Ring

379

H.S. Xu, X.Y. Li, N. Wang
IHEP, Beijing, People’s Republic of China

High Energy Photon Source (HEPS) is under construction in Beijing, China. The relatively complete impedance model has been built up based on the element-by-element impedance calculation. However, Coherent Synchrotron Radiation (CSR) impedance, which might affect the longitudinal performance of the beam, was not included in the impedance model of the HEPS storage ring in the preliminary design stage. For completeness, we would like to take the CSR impedance into consideration. The most important contributions to the total CSR impedance come from the bending magnets and insertion devices. We therefore calculate the CSR impedance from both above mentioned elements in HEPS storage ring. The influence of the CSR impedance on the microwave instability threshold is studied and presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB102

About •

paper received ※ 17 May 2021 paper accepted ※ 18 June 2021 issue date ※ 27 August 2021

Export •

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

WEPAB090

Higher Order Mode Damping for 166 MHz and 500 MHz Superconducting RF Cavities at High Energy Photon Source

2798

H.J. Zheng, Z.Q. Li, F. Meng, N. Wang, H.S. Xu, P. Zhang, X.Y. Zhang
IHEP, Beijing, People’s Republic of China

Funding: This work was supported in part by High Energy Photon Source, in part by the National Natural Science Foundation of China under Grant No. 11905232.
Superconducting rf cavities have been chosen for High Energy Photon Source, a 6 GeV diffraction-limited synchrotron light source under construction in Beijing. The main accelerating cavity adopted a quarter-wave β=1 structure operating at 166 MHz while the third harmonic cavity utilized the single-cell elliptical geometry at 500 MHz for the storage ring. The high beam current (200 mA) requires a strong damping of higher order modes (HOMs) excited in the superconducting cavities. To meet the beam stability requirements, enlarged beam pipes with a diameter of 505 mm for the 166 MHz cavity and 300 mm for the 500 MHz cavity were chosen to allow all HOMs to propagate along the beam tubes and to be damped by beam-line absorbers. This paper presents the HOM damping scheme and the cavity impedance analysis results. In addition, power losses due to HOMs were also evaluated for various operation modes (high charge and high luminosity) of the HEPS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB090

About •

paper received ※ 17 May 2021 paper accepted ※ 22 June 2021 issue date ※ 20 August 2021

Export •

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

WEPAB222

Impedance Evaluation of Masks in the HEPS Storage Ring

3145

N. Wang, S.K. Tian, J.Q. Wang
IHEP, Beijing, People’s Republic of China
J.Q. Wang
University of Chinese Academy of Sciences, Beijing, People’s Republic of China

Masks are commonly used in photon light sources to protect sensitive elements from synchrotron radiations. In the ultra-low emittance rings, small aperture vacuum chambers are adopted in order to reach the very high gradient in the quadrupoles, while many masks are required due to the high radiation power density. Therefore, the impedance of the masks becomes one of the dominant contributors to the impedance budget. In this paper, the impedance is evaluated among different mask designs. Meanwhile, the impedance cross-talk between adjacent masks is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB222

About •

paper received ※ 18 May 2021 paper accepted ※ 06 July 2021 issue date ※ 15 August 2021

Export •

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