IPAC2016 - List of Authors (Wang, N.)

Paper	Title	Page
MOPOR008	Beam Induced RF Heating in LHC in 2015	602
	B. Salvant, O. Aberle, M. Albert, R. Alemany-Fernandez, G. Arduini, J. Baechler, M.J. Barnes, P. Baudrenghien, O.E. Berrig, N. Biancacci, G. Bregliozzi, J.V. Campelo, F. Carra, F. Caspers, P. Chiggiato, A. Danisi, H.A. Day, M. Deile, D. Druzhkin, J.F. Esteban Müller, S. Jakobsen, J. Kuczerowski, A. Lechner, R. Losito, A. Masi, N. Minafra, E. Métral, A.A. Nosych, A. Perillo Marcone, D. Perini, S. Redaelli, F. Roncarolo, G. Rumolo, E.N. Shaposhnikova, J.A. Uythoven, C. Vollinger, A.J. Välimaa, N. Wang, M. Wendt, J. Wenninger, C. Zannini CERN, Geneva, Switzerland M. Bozzo INFN Genova, Genova, Italy J.F. Esteban Müller EPFL, Lausanne, Switzerland N. Wang IHEP, Beijing, People's Republic of China
	Following the recurrent beam induced RF issues that perturbed LHC operation during LHC Run 1, a series of actions were put in place to minimize the risk that similar issues would occur in LHC Run 2: longitudinal impedance reduction campaign and/or improvement of cooling for equipment that were problematic or at the limit during Run 1, stringent constraints enforced on new equipment that would be installed in the machine, tests to control the bunch length and longitudinal distribution, additional monitoring of temperature, new monitoring tools and warning chains. This contribution reports the outcome of these actions, both successes as well as shortcomings, and details the lessons learnt for the future runs.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR008
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOR010	Simulation of Instability at Transition Energy with a New Impedance Model for CERN PS	1674
	N. Wang IHEP, Beijing, People's Republic of China S. Aumon, N. Biancacci, M. Migliorati, G. Sterbini, N. Wang CERN, Geneva, Switzerland M. Migliorati INFN-Roma1, Rome, Italy S. Persichelli University of Rome La Sapienza, Rome, Italy
	Instabilities driven by the transverse impedance are proven to be one of the limitations for the high intensity reach of the CERN PS. Since several years, fast single bunch vertical instability at transition energy has been observed with the high intensity bunch serving the neu-tron Time-of-Flight facility (n-ToF). In order to better understand the instability mechanism, a dedicated meas-urement campaign took place. The results were compared with macro-particle simulations with PyHEADTAIL based on the new impedance model developed for the PS. Instability threshold and growth rate for different longitu-dinal emittances and beam intensities were studied.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR010
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUYA01	BEPCII Performance and Beam Dynamics Studies on Luminosity	1014
	C.H. Yu, Z. Duan, S. Gu, Y.Y. Guo, X.Y. Huang, D. Ji, H.F. Ji, Y. Jiao, Zh.C. Liu, Y.M. Peng, Q. Qin, Y.S. Sun, S.K. Tian, J.Q. Wang, N. Wang, X.H. Wang, Y. Wei, X.M. Wen, J. Wu, J. Xing, G. Xu, Y. Yue, C. Zhang, Y. Zhang IHEP, Beijing, People's Republic of China
	The upgrade of the Beijing Electron Positron Collider, BEPCII, is now in a good performance for both high energy physics and synchrotron radiation experiments. The luminosity at the design energy of 1.89 GeV reached the design value 1.0*10³³/cm²/s¹ recently. A lot of work, including accelerator physics study and technical progress, has been done for the luminosity enhancement, not only at the design energy, but all the energy region run for HEP experiments from 1.0 to 2.3 GeV. The performance of BEPCII and the process of luminosity enhancement will be described in detail.
	Slides TUYA01 [5.801 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUYA01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMW011	Current Status of Instability Threshold Measurements in the LHC at 6.5 TeV	1434
	L.R. Carver, J. Barranco, N. Biancacci, X. Buffat, W. Höfle, G. Kotzian, T. Lefèvre, T.E. Levens, E. Métral, T. Pieloni, B. Salvant, C. Tambasco CERN, Geneva, Switzerland N. Wang IHEP, Beijing, People's Republic of China M. Zobov INFN/LNF, Frascati (Roma), Italy
	Throughout 2015, many measurements of the minimum stabilizing octupole current required to prevent coherent transverse instabilities have been performed. These measurements allow the LHC impedance model at flat top to be verified and give good indicators of future performance and limitations. The results are summarized here, and compared to predictions from the simulation code DELPHI.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOW026	Recent Physical Studies for the HEPS Project	2886
	G. Xu, Z. Duan, Y.Y. Guo, D. Ji, Y. Jiao, X.Y. Li, Y.M. Peng, Q. Qin, J. Qiu, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, C.H. Yu IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS), a kilometre- scale storage ring light source, with a beam energy of 5 to 6 GeV and transverse emittances of a few tens of pm.rad, is to be built in Beijing and now is under design. In this paper we reported the progress and status of the physical studies for the HEPS project, covering issues of storage lattice design and optimization, booster design, injection design, collective effects, error study, insertion device effects, longitudinal dynamics, etc.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW026
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOR010	CEPC Parameter Choice and Partial Double Ring Design	3788
	D. Wang, S. Bai, T.J. Bian, X. Cui, Z. Duan, J. Gao, H. Geng, Y.Y. Guo, Q. Qin, N. Wang, Y. Wang, M. Xiao, J.Y. Zhai, C. Zhang, Y. Zhang IHEP, Beijing, People's Republic of China W. Chou Fermilab, Batavia, Illinois, USA F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	Funding: Work supported by the National Foundation of Natural Sciences (11505198 and 11575218) In order to avoid the pretzel orbit, CEPC is proposed to use partial double ring scheme in CDR. Based on crab waist scheme, we hope to either increase the luminosity with same beam power as Pre-CDR, or reduce the beam power while keeping the same luminosity in Pre-CDR. FFS with crab sextupoles has been developed and the arc lattice was redesigned to acheive the lower emittance for crab waist scheme.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR010
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOR017	Dynamic Aperture Optimization at CEPC with Pretzel Orbit	3808
	H. Geng, S. Bai, X. Cui, Z. Duan, J. Gao, Y.Y. Guo, Y.M. Peng, Q. Qin, D. Wang, N. Wang, Y. Wang, G. Xu, Y. Yue, Y. Zhang IHEP, Beijing, People's Republic of China W. Chou Fermilab, Batavia, Illinois, USA F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	A preliminary design of the CEPC ring with pretzel orbit will be presented. The ring and pretzel orbit will be designed for 50 bunches, as required in the CEPC Pre-CDR. The linear optics, as well as the non-linear chromaticity compensation with the presence of pretzel orbit will be described. Different phase advance difference between the long and short straight sections, have been tried to optimize the dynamic aperture, the results will be shown in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Induced RF Heating in LHC in 2015

602

B. Salvant, O. Aberle, M. Albert, R. Alemany-Fernandez, G. Arduini, J. Baechler, M.J. Barnes, P. Baudrenghien, O.E. Berrig, N. Biancacci, G. Bregliozzi, J.V. Campelo, F. Carra, F. Caspers, P. Chiggiato, A. Danisi, H.A. Day, M. Deile, D. Druzhkin, J.F. Esteban Müller, S. Jakobsen, J. Kuczerowski, A. Lechner, R. Losito, A. Masi, N. Minafra, E. Métral, A.A. Nosych, A. Perillo Marcone, D. Perini, S. Redaelli, F. Roncarolo, G. Rumolo, E.N. Shaposhnikova, J.A. Uythoven, C. Vollinger, A.J. Välimaa, N. Wang, M. Wendt, J. Wenninger, C. Zannini
CERN, Geneva, Switzerland
M. Bozzo
INFN Genova, Genova, Italy
J.F. Esteban Müller
EPFL, Lausanne, Switzerland
N. Wang
IHEP, Beijing, People's Republic of China

Following the recurrent beam induced RF issues that perturbed LHC operation during LHC Run 1, a series of actions were put in place to minimize the risk that similar issues would occur in LHC Run 2: longitudinal impedance reduction campaign and/or improvement of cooling for equipment that were problematic or at the limit during Run 1, stringent constraints enforced on new equipment that would be installed in the machine, tests to control the bunch length and longitudinal distribution, additional monitoring of temperature, new monitoring tools and warning chains. This contribution reports the outcome of these actions, both successes as well as shortcomings, and details the lessons learnt for the future runs.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR008

Export •

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

TUPOR010

Simulation of Instability at Transition Energy with a New Impedance Model for CERN PS

1674

N. Wang
IHEP, Beijing, People's Republic of China
S. Aumon, N. Biancacci, M. Migliorati, G. Sterbini, N. Wang
CERN, Geneva, Switzerland
M. Migliorati
INFN-Roma1, Rome, Italy
S. Persichelli
University of Rome La Sapienza, Rome, Italy

Instabilities driven by the transverse impedance are proven to be one of the limitations for the high intensity reach of the CERN PS. Since several years, fast single bunch vertical instability at transition energy has been observed with the high intensity bunch serving the neu-tron Time-of-Flight facility (n-ToF). In order to better understand the instability mechanism, a dedicated meas-urement campaign took place. The results were compared with macro-particle simulations with PyHEADTAIL based on the new impedance model developed for the PS. Instability threshold and growth rate for different longitu-dinal emittances and beam intensities were studied.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR010

Export •

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

TUYA01

BEPCII Performance and Beam Dynamics Studies on Luminosity

1014

C.H. Yu, Z. Duan, S. Gu, Y.Y. Guo, X.Y. Huang, D. Ji, H.F. Ji, Y. Jiao, Zh.C. Liu, Y.M. Peng, Q. Qin, Y.S. Sun, S.K. Tian, J.Q. Wang, N. Wang, X.H. Wang, Y. Wei, X.M. Wen, J. Wu, J. Xing, G. Xu, Y. Yue, C. Zhang, Y. Zhang
IHEP, Beijing, People's Republic of China

The upgrade of the Beijing Electron Positron Collider, BEPCII, is now in a good performance for both high energy physics and synchrotron radiation experiments. The luminosity at the design energy of 1.89 GeV reached the design value 1.0*10³³/cm²/s¹ recently. A lot of work, including accelerator physics study and technical progress, has been done for the luminosity enhancement, not only at the design energy, but all the energy region run for HEP experiments from 1.0 to 2.3 GeV. The performance of BEPCII and the process of luminosity enhancement will be described in detail.

Slides TUYA01 [5.801 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUYA01

Export •

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

TUPMW011

Current Status of Instability Threshold Measurements in the LHC at 6.5 TeV

1434

L.R. Carver, J. Barranco, N. Biancacci, X. Buffat, W. Höfle, G. Kotzian, T. Lefèvre, T.E. Levens, E. Métral, T. Pieloni, B. Salvant, C. Tambasco
CERN, Geneva, Switzerland
N. Wang
IHEP, Beijing, People's Republic of China
M. Zobov
INFN/LNF, Frascati (Roma), Italy

Throughout 2015, many measurements of the minimum stabilizing octupole current required to prevent coherent transverse instabilities have been performed. These measurements allow the LHC impedance model at flat top to be verified and give good indicators of future performance and limitations. The results are summarized here, and compared to predictions from the simulation code DELPHI.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW011

Export •

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

WEPOW026

Recent Physical Studies for the HEPS Project

2886

G. Xu, Z. Duan, Y.Y. Guo, D. Ji, Y. Jiao, X.Y. Li, Y.M. Peng, Q. Qin, J. Qiu, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, C.H. Yu
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS), a kilometre- scale storage ring light source, with a beam energy of 5 to 6 GeV and transverse emittances of a few tens of pm.rad, is to be built in Beijing and now is under design. In this paper we reported the progress and status of the physical studies for the HEPS project, covering issues of storage lattice design and optimization, booster design, injection design, collective effects, error study, insertion device effects, longitudinal dynamics, etc.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW026

Export •

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

THPOR010

CEPC Parameter Choice and Partial Double Ring Design

3788

D. Wang, S. Bai, T.J. Bian, X. Cui, Z. Duan, J. Gao, H. Geng, Y.Y. Guo, Q. Qin, N. Wang, Y. Wang, M. Xiao, J.Y. Zhai, C. Zhang, Y. Zhang
IHEP, Beijing, People's Republic of China
W. Chou
Fermilab, Batavia, Illinois, USA
F. Su
Institute of High Energy Physics (IHEP), People's Republic of China

Funding: Work supported by the National Foundation of Natural Sciences (11505198 and 11575218)
In order to avoid the pretzel orbit, CEPC is proposed to use partial double ring scheme in CDR. Based on crab waist scheme, we hope to either increase the luminosity with same beam power as Pre-CDR, or reduce the beam power while keeping the same luminosity in Pre-CDR. FFS with crab sextupoles has been developed and the arc lattice was redesigned to acheive the lower emittance for crab waist scheme.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR010

Export •

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

THPOR017

Dynamic Aperture Optimization at CEPC with Pretzel Orbit

3808

H. Geng, S. Bai, X. Cui, Z. Duan, J. Gao, Y.Y. Guo, Y.M. Peng, Q. Qin, D. Wang, N. Wang, Y. Wang, G. Xu, Y. Yue, Y. Zhang
IHEP, Beijing, People's Republic of China
W. Chou
Fermilab, Batavia, Illinois, USA
F. Su
Institute of High Energy Physics (IHEP), People's Republic of China

A preliminary design of the CEPC ring with pretzel orbit will be presented. The ring and pretzel orbit will be designed for 50 bunches, as required in the CEPC Pre-CDR. The linear optics, as well as the non-linear chromaticity compensation with the presence of pretzel orbit will be described. Different phase advance difference between the long and short straight sections, have been tried to optimize the dynamic aperture, the results will be shown in this paper.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR017

Export •

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