IPAC2021 - List of Authors (Xu, H.S.)

Paper	Title	Page
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
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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
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TUPAB220	Longitudinal Dynamics with Harmonic Cavities under the Over-stretching Conditions	1939
	J.Y. Xu, H.S. Xu IHEP, Beijing, People’s Republic of China
	Higher harmonic cavities (HHCs) are often used to lengthen the bunches, mainly for increasing the Touschek lifetime or for suppressing the coupled-bunch instabilities in electron storage rings. There have been quite many studies on the beam dynamics with the consideration of HHCs. We revisited the basic longitudinal dynamics with HHCs. The derivation of the longitudinal equations of motion with HHCs will be presented in this paper. The difference in the number of fixed points at different HHC settings (mainly under the over-stretching conditions) is also discussed.
	Poster TUPAB220 [1.082 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB220
About •	paper received ※ 19 May 2021 paper accepted ※ 02 August 2021 issue date ※ 29 August 2021
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TUPAB226	Study of the Third-Order Parametric Resonance Induced by RF Modulation	1956
	P.F. Liang, H.S. Xu IHEP, Beijing, People’s Republic of China
	There were both analytic and experimental studies on the effects of RF modulation on bunch lengthening in electron storage rings. Nevertheless, the increase of bunch energy spread will happen in the meantime. Therefore, the degradation of bunch quality may limit the potential applications of the RF modulation technique. As a consequence, we believe that the comprehensive studies of the parametric resonance induced by RF modulation are necessary for understanding the physics picture better and seeking new possibilities of applications of this technique. The studies on the beam dynamics closed to the 3v_s RF phase modulation would be presented here. Based on the basic longitudinal synchrotron equations of motion, we obtained analytically the longitudinal modulated Hamiltonian and various parameters in longitudinal phase space, such as the fixed points, island tune, island width. The validity of the analytic results was checked by simulations. Furthermore, the dependence of the bunch parameters, such as energy spread and bunch length, on the modulation settings is also discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB226
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 13 August 2021
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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)

Paper

Title

Page

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)

TUPAB220

Longitudinal Dynamics with Harmonic Cavities under the Over-stretching Conditions

1939

J.Y. Xu, H.S. Xu
IHEP, Beijing, People’s Republic of China

Higher harmonic cavities (HHCs) are often used to lengthen the bunches, mainly for increasing the Touschek lifetime or for suppressing the coupled-bunch instabilities in electron storage rings. There have been quite many studies on the beam dynamics with the consideration of HHCs. We revisited the basic longitudinal dynamics with HHCs. The derivation of the longitudinal equations of motion with HHCs will be presented in this paper. The difference in the number of fixed points at different HHC settings (mainly under the over-stretching conditions) is also discussed.

Poster TUPAB220 [1.082 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB220

About •

paper received ※ 19 May 2021 paper accepted ※ 02 August 2021 issue date ※ 29 August 2021

Export •

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

TUPAB226

Study of the Third-Order Parametric Resonance Induced by RF Modulation

1956

P.F. Liang, H.S. Xu
IHEP, Beijing, People’s Republic of China

There were both analytic and experimental studies on the effects of RF modulation on bunch lengthening in electron storage rings. Nevertheless, the increase of bunch energy spread will happen in the meantime. Therefore, the degradation of bunch quality may limit the potential applications of the RF modulation technique. As a consequence, we believe that the comprehensive studies of the parametric resonance induced by RF modulation are necessary for understanding the physics picture better and seeking new possibilities of applications of this technique. The studies on the beam dynamics closed to the 3v_s RF phase modulation would be presented here. Based on the basic longitudinal synchrotron equations of motion, we obtained analytically the longitudinal modulated Hamiltonian and various parameters in longitudinal phase space, such as the fixed points, island tune, island width. The validity of the analytic results was checked by simulations. Furthermore, the dependence of the bunch parameters, such as energy spread and bunch length, on the modulation settings is also discussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB226

About •

paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 13 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)