IPAC2018 - List of Authors (Zhang, Y.)

Paper	Title	Page
MOPMF079	The CEPC lattice design with combined dipole magnet	315
	D. Wang, S. Bai, F.S. Chen, W. Chou, J. Gao, Y.M. Peng, Y. Wang, M. Yang, C.H. Yu, Y. Zhang IHEP, Beijing, People's Republic of China
	For the lattice of CEPC collider ring, the combined magnet (dipole+sextupole) scheme has been developed to reduce the power consumption of the stand-alone sextu-poles. The power consumption of sextupoles has been decreased by 75% due to 50% reduction of strength. The dynamic aperture for the combined magnet scheme is as good as the original lattice. The magnet design for this kind of combined dipole has been done which provides a good support for this new idea.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF079
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MOPMK017	Transient Beam Loading Due to the Bunch Train Gap and Its Compensation Experiments at BEPC-II and ALS	390
	H. Wang, R.A. Rimmer, S. Wang JLab, Newport News, Virginia, USA J.P. Dai, Q. Qin, J. Xing, J.H. Yue, Y. Zhang IHEP, Beijing, People's Republic of China D. Teytelman Dimtel, San Jose, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Non-uniform bunch fill patterns in storage rings, driven by the need to provide gaps for beam aborting and ion clearing cause a large beam loading change in the RF cavities. The induced turn-periodic transient in the cavity voltage modulates longitudinal beam properties along the train, such as synchronous position and bunch length. In the EIC design, due to the asymmetric bunch train structure between the electron and the ion beam, such modulation results in shifting collision point and leads to reduced luminosity. We have carried out the beam based experiments at BEPC-II and ALS using bunch-by-bunch diagnostic capabilities of the coupled-bunch feedback systems to study this transient effect. A modulated bunch filling pattern with higher charge density around the gap has been demonstrated to be effective in partially compensating this transient modulation. Details of the experimental setups and the data analysis will be presented to this conference.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK017
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TUYGBD4	Beam Loss Background and Collimator Design in CEPC Double Ring	632
	S. Bai, J. Gao, H. Geng, D. Wang, Y. Wang, C.H. Yu, Y. Zhang IHEP, 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. Radiative Bhabha scattering and Beamstrahlung effects are dominant mechanism of the beam induced backgrounds at CEPC due to the beam lifetime. In this paper, we evaluated the beam loss background in simulation and designed a series of collimators to suppress the radiation level on the machine and the detector.
	Slides TUYGBD4 [0.791 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUYGBD4
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THPAK016	Measurement and Analysis of Synchrotron Tune Variation with Beam Current in BEPCII	3237
	N. Wang, Z. Duan, G. Xu, H.S. Xu, C.H. Yu, Y. Zhang IHEP, Beijing, People's Republic of China
	Coherent synchrotron frequency shift is observed during machine studies in BEPCII (Beijing Electron Positron Collider Upgrade). The results show that the synchrotron frequency varies parabolically with the increase of the beam current. This phenomenon is supposed to be induced by the interaction of the beam with the fundamental mode of the accelerating cavity. In order to explain this phenomenon, a simple physical model is developed from the couple bunch instability theory. The analytical estimations based on the physical model show good agreement with the measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK016
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Paper

Title

Page

The CEPC lattice design with combined dipole magnet

315

D. Wang, S. Bai, F.S. Chen, W. Chou, J. Gao, Y.M. Peng, Y. Wang, M. Yang, C.H. Yu, Y. Zhang
IHEP, Beijing, People's Republic of China

For the lattice of CEPC collider ring, the combined magnet (dipole+sextupole) scheme has been developed to reduce the power consumption of the stand-alone sextu-poles. The power consumption of sextupoles has been decreased by 75% due to 50% reduction of strength. The dynamic aperture for the combined magnet scheme is as good as the original lattice. The magnet design for this kind of combined dipole has been done which provides a good support for this new idea.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF079

Export •

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

MOPMK017

Transient Beam Loading Due to the Bunch Train Gap and Its Compensation Experiments at BEPC-II and ALS

390

H. Wang, R.A. Rimmer, S. Wang
JLab, Newport News, Virginia, USA
J.P. Dai, Q. Qin, J. Xing, J.H. Yue, Y. Zhang
IHEP, Beijing, People's Republic of China
D. Teytelman
Dimtel, San Jose, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Non-uniform bunch fill patterns in storage rings, driven by the need to provide gaps for beam aborting and ion clearing cause a large beam loading change in the RF cavities. The induced turn-periodic transient in the cavity voltage modulates longitudinal beam properties along the train, such as synchronous position and bunch length. In the EIC design, due to the asymmetric bunch train structure between the electron and the ion beam, such modulation results in shifting collision point and leads to reduced luminosity. We have carried out the beam based experiments at BEPC-II and ALS using bunch-by-bunch diagnostic capabilities of the coupled-bunch feedback systems to study this transient effect. A modulated bunch filling pattern with higher charge density around the gap has been demonstrated to be effective in partially compensating this transient modulation. Details of the experimental setups and the data analysis will be presented to this conference.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK017

Export •

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

TUYGBD4

Beam Loss Background and Collimator Design in CEPC Double Ring

632

S. Bai, J. Gao, H. Geng, D. Wang, Y. Wang, C.H. Yu, Y. Zhang
IHEP, 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. Radiative Bhabha scattering and Beamstrahlung effects are dominant mechanism of the beam induced backgrounds at CEPC due to the beam lifetime. In this paper, we evaluated the beam loss background in simulation and designed a series of collimators to suppress the radiation level on the machine and the detector.

Slides TUYGBD4 [0.791 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUYGBD4

Export •

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

THPAK016

Measurement and Analysis of Synchrotron Tune Variation with Beam Current in BEPCII

3237

N. Wang, Z. Duan, G. Xu, H.S. Xu, C.H. Yu, Y. Zhang
IHEP, Beijing, People's Republic of China

Coherent synchrotron frequency shift is observed during machine studies in BEPCII (Beijing Electron Positron Collider Upgrade). The results show that the synchrotron frequency varies parabolically with the increase of the beam current. This phenomenon is supposed to be induced by the interaction of the beam with the fundamental mode of the accelerating cavity. In order to explain this phenomenon, a simple physical model is developed from the couple bunch instability theory. The analytical estimations based on the physical model show good agreement with the measurements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK016

Export •

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