eeFACT2018 - Classification: Injector and injection

Paper	Title	Page
TUPAB01	KEKB Injection Developments	121
	K. Furukawa KEK, Ibaraki, Japan
	The e⁻/e⁺ SuperKEKB collider is now under commissioning. As e⁻/e⁺ beam injection for SuperKEKB greatly depends on the efforts during the previous KEKB project, the injection developments during KEKB are outlined as well as the improvements towards SuperKEKB. When KEKB was commissioned, approximately ten experimental runs per day were performed with e⁻/e⁺ injections in between. As another collider PEP-II had a powerful injector SLAC, the KEKB injector had to make a few improvements seriously, such as injection of two bunches in a pulse, continuous injection scheme, eventual simultaneous top-up injections, as well as many operational optimizations. The design of SuperKEKB further required the beam quality improvements especially in the lower beam emittance for the nano-beam scheme, as well as in the beam current for the higher ring stored current and the shorter lifetime.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB01
About •	paper received ※ 20 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019
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TUPAB02	Low Emittance Beam Transport for e⁻/e⁺ LINAC	126
	Y. Seimiya, N. Iida, M. Kikuchi, T. Mori KEK, Ibaraki, Japan
	Design luminosity of SuperKEKB is 8 x 10³⁵ cm^-2s^-1, which is 40 times higher than that of KEKB achieved. To achieve the design luminosity, the beam have to be transported to the SuperKEKB main ring with the high bunch charge (4 nC) and low emittance: 40/20 um for horizontal/vertical electron beam emittance and 100/15 um for positron beam emittance in Phase 3 final. In the LINAC and the beam transport line, the emittance growth is mainly induced by residual dispersion, beam phase space jitter, wakefield in acceleration structure, and radiation excitation. In the Phase 2 operation, we have evaluated and, if possible, corrected these effects on the emittance. Results of the emittance measurement is described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB02
About •	paper received ※ 19 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019
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TUPAB03	Overall Injection Strategy for FCC-ee	131
	S. Ogur, F. Antoniou, T.K. Charles, B. Härer, B.J. Holzer, Y. Papaphilippou, L. Rinolfi, T. Tydecks, F. Zimmermann CERN, Geneva, Switzerland M. Aiba PSI, Villigen PSI, Switzerland A.M. Barnyakov, A.E. Levichev, P.V. Martyshkin, D.A. Nikiforov BINP SB RAS, Novosibirsk, Russia I. Chaikovska, R. Chehab LAL, Orsay, France O. Etisken Ankara University, Faculty of Sciences, Ankara, Turkey K. Furukawa, N. Iida, T. Kamitani, F. Miyahara KEK, Ibaraki, Japan E.V. Ozcan Bogazici University, Bebek / Istanbul, Turkey S.M. Polozov MEPhI, Moscow, Russia
	The Future Circular electron-positron Collider (FCC-ee) requires fast cycling injectors with very low extraction emittances to provide and maintain extreme luminosities at center of mass energy varying between 91.2-385 GeV in the collider. For this reason, the whole injector complex table is prepared by putting into consideration the minimum fill time from scratch, bootstrapping, transmission efficiency as well as store time of the beams in synchrotrons to approach equilibrium emittances. The current injector baseline contains 6 GeV S-band linac, a damping ring at 1.54 GeV, a prebooster to accelerate from 6 to 20 GeV, which is followed by 98-km top up booster accelerating up to final collision energies. Acceleration from 6 GeV to 20 GeV can be provided either by Super Proton Synchrotron (SPS) of CERN or a new synchrotron or C-Band linac, distinctively, which all options are retained. In this paper, the current status of the whole FCC-ee injector complex and injection strategies are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB03
About •	paper received ※ 20 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019
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TUPAB04	Overall Design of the CEPC Injector LINAC	139
	J.R. Zhang, Y.L. Chi, J. Gao, X.P. Li, C. Meng, G. Pei, S. Pei, D. Wang, C.H. Yu IHEP, Beijing, People’s Republic of China
	The CEPC injector consists of linac and booster. To meet the requirement of the booster, the linac should provide 10 GeV electron and positron beam at a repetition frequency of 100 Hz. In this paper, the overall design of the linac has introduced. For the linac one-bunch-per-pulse is adopted and bunch charge should be larger than 3 nC in the design. A 1.1 GeV damping ring with 75.4 m circumference has adopted to reduce the transverse emittance of positron beam to suitably small value.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB04
About •	paper received ※ 26 September 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019
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TUPAB05	An On-axis Injection Design for CEPC	143
	X. Cui, C.H. Yu, J.Y. Zhai, Y. Zhang IHEP, Beijing, People’s Republic of China
	Considering the requirement on the dynamic aperture in the main collider, an on-axis injection method is need-ed for the Higgs energy at CEPC. A swap-out on-axis injection scheme using the booster as an accumulation ring is given in this paper. Some dynamical problems concerning the effectiveness of this injection scheme is also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB05
About •	paper received ※ 27 September 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019
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TUPAB06	Design and Beam Dynamics of the CEPC Booster	146
	D. Wang, X. Cui, J. Gao, D. Ji, Y.D. Liu, C. Meng, N. Wang, C.H. Yu, J.Y. Zhai, Y. Zhang IHEP, Beijing, People’s Republic of China
	The CEPC booster needs to provide electron and positron beams to the collider at different energy with required injection speed. A 10 GeV linac is adopted as the injector for CDR. Then the beam energy is accelerated to specific energy according to three modes of CEPC collider ring (H, W and Z). The geometry of booster is designed carefully in order to share the same tunnel with collider. The design status of booster including parameters, optics and dynamic aperture is discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB06
About •	paper received ※ 26 September 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019
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TUPAB07	Commissioning of Positron Damping Ring and the Beam Transport for SuperKEKB	152
	N. Iida, Y. Funakoshi, H. Ikeda, T. Ishibashi, H. Kaji, T. Kamitani, M. Kikuchi, T. Kobayashi, H. Koiso, F. Miyahara, T. Mori, Y. Ohnishi, Y. Seimiya, H. Sugimoto, H. Sugimura, R. Ueki, Y. Yano, D. Zhou KEK, Ibaraki, Japan
	The Positron Damping Ring (DR) for SuperKEKB successfully started its operation in February 2018, and the commissioning was continued until the end of SuperKEKB Phase 2 in July without serious troubles. This paper describes achievements of the beam commissioning of injection and extraction lines (LTR and RTL) between the LINAC and DR. In the LTR commissioning, the positron beam with high emittance, wide energy spread, and high charge were transported and injected into the DR. In the RTL commissioning, special cares were necessary to preserve the low emittance. The observed emittance growth in the RTL was not a problem for Phase 2, but it should be resolved in the coming Phase 3. In this paper, brief results of the commissioning of the DR is also reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB07
About •	paper received ※ 20 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

KEKB Injection Developments

121

K. Furukawa
KEK, Ibaraki, Japan

The e⁻/e⁺ SuperKEKB collider is now under commissioning. As e⁻/e⁺ beam injection for SuperKEKB greatly depends on the efforts during the previous KEKB project, the injection developments during KEKB are outlined as well as the improvements towards SuperKEKB. When KEKB was commissioned, approximately ten experimental runs per day were performed with e⁻/e⁺ injections in between. As another collider PEP-II had a powerful injector SLAC, the KEKB injector had to make a few improvements seriously, such as injection of two bunches in a pulse, continuous injection scheme, eventual simultaneous top-up injections, as well as many operational optimizations. The design of SuperKEKB further required the beam quality improvements especially in the lower beam emittance for the nano-beam scheme, as well as in the beam current for the higher ring stored current and the shorter lifetime.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB01

About •

paper received ※ 20 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019

Export •

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

TUPAB02

Low Emittance Beam Transport for e⁻/e⁺ LINAC

126

Y. Seimiya, N. Iida, M. Kikuchi, T. Mori
KEK, Ibaraki, Japan

Design luminosity of SuperKEKB is 8 x 10³⁵ cm^-2s^-1, which is 40 times higher than that of KEKB achieved. To achieve the design luminosity, the beam have to be transported to the SuperKEKB main ring with the high bunch charge (4 nC) and low emittance: 40/20 um for horizontal/vertical electron beam emittance and 100/15 um for positron beam emittance in Phase 3 final. In the LINAC and the beam transport line, the emittance growth is mainly induced by residual dispersion, beam phase space jitter, wakefield in acceleration structure, and radiation excitation. In the Phase 2 operation, we have evaluated and, if possible, corrected these effects on the emittance. Results of the emittance measurement is described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB02

About •

paper received ※ 19 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019

Export •

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

TUPAB03

Overall Injection Strategy for FCC-ee

131

S. Ogur, F. Antoniou, T.K. Charles, B. Härer, B.J. Holzer, Y. Papaphilippou, L. Rinolfi, T. Tydecks, F. Zimmermann
CERN, Geneva, Switzerland
M. Aiba
PSI, Villigen PSI, Switzerland
A.M. Barnyakov, A.E. Levichev, P.V. Martyshkin, D.A. Nikiforov
BINP SB RAS, Novosibirsk, Russia
I. Chaikovska, R. Chehab
LAL, Orsay, France
O. Etisken
Ankara University, Faculty of Sciences, Ankara, Turkey
K. Furukawa, N. Iida, T. Kamitani, F. Miyahara
KEK, Ibaraki, Japan
E.V. Ozcan
Bogazici University, Bebek / Istanbul, Turkey
S.M. Polozov
MEPhI, Moscow, Russia

The Future Circular electron-positron Collider (FCC-ee) requires fast cycling injectors with very low extraction emittances to provide and maintain extreme luminosities at center of mass energy varying between 91.2-385 GeV in the collider. For this reason, the whole injector complex table is prepared by putting into consideration the minimum fill time from scratch, bootstrapping, transmission efficiency as well as store time of the beams in synchrotrons to approach equilibrium emittances. The current injector baseline contains 6 GeV S-band linac, a damping ring at 1.54 GeV, a prebooster to accelerate from 6 to 20 GeV, which is followed by 98-km top up booster accelerating up to final collision energies. Acceleration from 6 GeV to 20 GeV can be provided either by Super Proton Synchrotron (SPS) of CERN or a new synchrotron or C-Band linac, distinctively, which all options are retained. In this paper, the current status of the whole FCC-ee injector complex and injection strategies are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB03

About •

paper received ※ 20 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019

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

TUPAB04

Overall Design of the CEPC Injector LINAC

139

J.R. Zhang, Y.L. Chi, J. Gao, X.P. Li, C. Meng, G. Pei, S. Pei, D. Wang, C.H. Yu
IHEP, Beijing, People’s Republic of China

The CEPC injector consists of linac and booster. To meet the requirement of the booster, the linac should provide 10 GeV electron and positron beam at a repetition frequency of 100 Hz. In this paper, the overall design of the linac has introduced. For the linac one-bunch-per-pulse is adopted and bunch charge should be larger than 3 nC in the design. A 1.1 GeV damping ring with 75.4 m circumference has adopted to reduce the transverse emittance of positron beam to suitably small value.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB04

About •

paper received ※ 26 September 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019

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

TUPAB05

An On-axis Injection Design for CEPC

143

X. Cui, C.H. Yu, J.Y. Zhai, Y. Zhang
IHEP, Beijing, People’s Republic of China

Considering the requirement on the dynamic aperture in the main collider, an on-axis injection method is need-ed for the Higgs energy at CEPC. A swap-out on-axis injection scheme using the booster as an accumulation ring is given in this paper. Some dynamical problems concerning the effectiveness of this injection scheme is also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB05

About •

paper received ※ 27 September 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019

Export •

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

TUPAB06

Design and Beam Dynamics of the CEPC Booster

146

D. Wang, X. Cui, J. Gao, D. Ji, Y.D. Liu, C. Meng, N. Wang, C.H. Yu, J.Y. Zhai, Y. Zhang
IHEP, Beijing, People’s Republic of China

The CEPC booster needs to provide electron and positron beams to the collider at different energy with required injection speed. A 10 GeV linac is adopted as the injector for CDR. Then the beam energy is accelerated to specific energy according to three modes of CEPC collider ring (H, W and Z). The geometry of booster is designed carefully in order to share the same tunnel with collider. The design status of booster including parameters, optics and dynamic aperture is discussed in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB06

About •

paper received ※ 26 September 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019

Export •

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

TUPAB07

Commissioning of Positron Damping Ring and the Beam Transport for SuperKEKB

152

N. Iida, Y. Funakoshi, H. Ikeda, T. Ishibashi, H. Kaji, T. Kamitani, M. Kikuchi, T. Kobayashi, H. Koiso, F. Miyahara, T. Mori, Y. Ohnishi, Y. Seimiya, H. Sugimoto, H. Sugimura, R. Ueki, Y. Yano, D. Zhou
KEK, Ibaraki, Japan

The Positron Damping Ring (DR) for SuperKEKB successfully started its operation in February 2018, and the commissioning was continued until the end of SuperKEKB Phase 2 in July without serious troubles. This paper describes achievements of the beam commissioning of injection and extraction lines (LTR and RTL) between the LINAC and DR. In the LTR commissioning, the positron beam with high emittance, wide energy spread, and high charge were transported and injected into the DR. In the RTL commissioning, special cares were necessary to preserve the low emittance. The observed emittance growth in the RTL was not a problem for Phase 2, but it should be resolved in the coming Phase 3. In this paper, brief results of the commissioning of the DR is also reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPAB07

About •

paper received ※ 20 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019

Export •

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