eeFACT2016 - List of Keywords (coupling)

Paper	Title	Other Keywords	Page
TUT3AH2	Instability Issues in CEPC	ion, impedance, cavity, damping	108
	N. Wang, W. Chou, J. Gao, D.J. Gong, J. He, Q. Qin, Y.S. Sun, D. Wang, Y. Wang, G. Xu, Y. Zhang, H.J. Zheng IHEP, Beijing, People's Republic of China K. Ohmi, D. Zhou KEK, Ibaraki, Japan
	The CEPC is a high energy circular electron-positron collider under design. Large bunch population is required to achieve the design luminosity. Instabilities driven by the coupling impedance are possible limitations for reaching high machine performance. An updated impedance model, including the resistive wall and the main vacuum components, has been obtained for the main ring. Based on the impedance model, the collective instability issues of the beam with the partial-double ring design are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT3AH2
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TUT3BH2	Optics Correction and Low Emittance Tuning at the Phase 1 commissioning of SuperKEKB	ion, sextupole, emittance, optics	143
	Y. Ohnishi, Y. Funakoshi, H. Koiso, A. Morita, K. Oide, H. Sugimoto KEK, Ibaraki, Japan
	The SuperKEKB collider has finally come to the first commissioning, Phase 1 without the final focus system and before Belle II detector roll-in. In order to accomplish a extremely high luminosity of 8x10³⁵ cm^-2s^-1, the nano-beam scheme is adopted. Since the vertical emittance is one of keys in this scheme, optics corrections for low emittance tuning are applied. The non-interleaved sextupole scheme is utilized in the arc section. Skew quadrupole-like corrector is equipped for each sextupole. These skew quadrupole-like correctors can correct both X-Y coupling and physical vertical dispersions which induce the vertical emittance. Beta function and physical horizontal dispersion are corrected by fudge factors of quadrupoles and/or horizontal orbit bumps at the sextupoles. Overall optics performance as well as the strategy of low emittance tuning is also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT3BH2
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TUT3BH3	Luminosity Tuning at KEKB	ion, luminosity, injection, operation	147
	Y. Funakoshi KEK, Ibaraki, Japan
	KEKB achieved the world's highest luminosity. One of the key issues for the high luminosity at KEKB was a luminosity tuning which was done almost every time even during the physics run to suppress the beam-beam blowup. In this talk, those experiences are summarized. Some experiences of the luminosity tuning at TRISTAN will also mentioned.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT3BH3
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TUT3BH4	Coupling and Dispersion Correction for the Tolerance Study in FCC-ee	ion, emittance, quadrupole, lattice	151
	S. Aumon, A. Doblhammer, B. Härer, B.J. Holzer CERN, Geneva, Switzerland B. Härer KIT, Karlsruhe, Germany K. Oide KEK, Ibaraki, Japan
	The FCC-ee study is investigating the design of a 100 km e⁺/e⁻ circular collider for precision measurements and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 10³⁵ cm^-2s^-1. In order to reach such performances, an extreme focusing of the beam is required in the interaction regions with a low vertical beta function of 2 mm at the IP. Moreover, the FCC-ee physics program requires very low emittances never achieved in a collider with 1.3 nm for ε_x and 2 pm for ε_y at 175~GeV, reducing the coupling ratio to around 2/1000. With such requirements, any field errors and sources of coupling will introduce spurious vertical dispersion which degrades emittances, limiting the luminosity of the machine. This study describes the status of the tolerance study and the impact of errors that will affect the vertical emittance. In order to preserve the FCC-ee performances, in particular ε_y, a challenging correction scheme based on dispersion free steering and linear coupling correction is proposed to keep the coupling and the vertical emittance as low as possible.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT3BH4
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THS2H2	Summary of Machine Tuning Session	ion, luminosity, optics, emittance	216
	M.E. Biagini INFN/LNF, Frascati (Roma), Italy
	This paper summarizes the work presented at the Machine Tuning session on the low emittance tuning for low emittance lattices and luminosity tuning at colliders.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-THS2H2
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Paper

Title

Other Keywords

Page

TUT3AH2

Instability Issues in CEPC

ion, impedance, cavity, damping

108

N. Wang, W. Chou, J. Gao, D.J. Gong, J. He, Q. Qin, Y.S. Sun, D. Wang, Y. Wang, G. Xu, Y. Zhang, H.J. Zheng
IHEP, Beijing, People's Republic of China
K. Ohmi, D. Zhou
KEK, Ibaraki, Japan

The CEPC is a high energy circular electron-positron collider under design. Large bunch population is required to achieve the design luminosity. Instabilities driven by the coupling impedance are possible limitations for reaching high machine performance. An updated impedance model, including the resistive wall and the main vacuum components, has been obtained for the main ring. Based on the impedance model, the collective instability issues of the beam with the partial-double ring design are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT3AH2

Export •

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

TUT3BH2

Optics Correction and Low Emittance Tuning at the Phase 1 commissioning of SuperKEKB

ion, sextupole, emittance, optics

143

Y. Ohnishi, Y. Funakoshi, H. Koiso, A. Morita, K. Oide, H. Sugimoto
KEK, Ibaraki, Japan

The SuperKEKB collider has finally come to the first commissioning, Phase 1 without the final focus system and before Belle II detector roll-in. In order to accomplish a extremely high luminosity of 8x10³⁵ cm^-2s^-1, the nano-beam scheme is adopted. Since the vertical emittance is one of keys in this scheme, optics corrections for low emittance tuning are applied. The non-interleaved sextupole scheme is utilized in the arc section. Skew quadrupole-like corrector is equipped for each sextupole. These skew quadrupole-like correctors can correct both X-Y coupling and physical vertical dispersions which induce the vertical emittance. Beta function and physical horizontal dispersion are corrected by fudge factors of quadrupoles and/or horizontal orbit bumps at the sextupoles. Overall optics performance as well as the strategy of low emittance tuning is also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT3BH2

Export •

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

TUT3BH3

Luminosity Tuning at KEKB

ion, luminosity, injection, operation

147

Y. Funakoshi
KEK, Ibaraki, Japan

KEKB achieved the world's highest luminosity. One of the key issues for the high luminosity at KEKB was a luminosity tuning which was done almost every time even during the physics run to suppress the beam-beam blowup. In this talk, those experiences are summarized. Some experiences of the luminosity tuning at TRISTAN will also mentioned.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT3BH3

Export •

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

TUT3BH4

Coupling and Dispersion Correction for the Tolerance Study in FCC-ee

ion, emittance, quadrupole, lattice

151

S. Aumon, A. Doblhammer, B. Härer, B.J. Holzer
CERN, Geneva, Switzerland
B. Härer
KIT, Karlsruhe, Germany
K. Oide
KEK, Ibaraki, Japan

The FCC-ee study is investigating the design of a 100 km e⁺/e⁻ circular collider for precision measurements and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 10³⁵ cm^-2s^-1. In order to reach such performances, an extreme focusing of the beam is required in the interaction regions with a low vertical beta function of 2 mm at the IP. Moreover, the FCC-ee physics program requires very low emittances never achieved in a collider with 1.3 nm for ε_x and 2 pm for ε_y at 175~GeV, reducing the coupling ratio to around 2/1000. With such requirements, any field errors and sources of coupling will introduce spurious vertical dispersion which degrades emittances, limiting the luminosity of the machine. This study describes the status of the tolerance study and the impact of errors that will affect the vertical emittance. In order to preserve the FCC-ee performances, in particular ε_y, a challenging correction scheme based on dispersion free steering and linear coupling correction is proposed to keep the coupling and the vertical emittance as low as possible.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT3BH4

Export •

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

THS2H2

Summary of Machine Tuning Session

ion, luminosity, optics, emittance

216

M.E. Biagini
INFN/LNF, Frascati (Roma), Italy

This paper summarizes the work presented at the Machine Tuning session on the low emittance tuning for low emittance lattices and luminosity tuning at colliders.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-THS2H2

Export •

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