eeFACT2016 - List of Keywords (emittance)

Paper	Title	Other Keywords	Page
MOOTH2	Commissioning of SuperKEKB	ion, MMI, vacuum, detector	4
	Y. Funakoshi KEK, Ibaraki, Japan
	After 5 years of upgrade work from KEKB, the Phase 1 beam commissioning of SuperKEKB started on Feb. 1st this year and finished at the end of June. In Phase 1, Belle-II detector and the final focus doublet (QCS) were not installed and no beam collision was performed. Missions of the commissioning in Phase 1 were startup of each hardware component, establishment of beam operation software tools, preparation of Belle-II detector, an optics study and tuning without QCS and the detector solenoid magnet and other machine studies. In this talk, achievements in the Phase 1 commissioning are summarized. Also a plan for the Phase 2 commissioning will be given.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-MOOTH2
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MOOTH4	Performance and Perspective of Modern Synchrotron Light Sources	ion, synchrotron, lattice, SRF	17
	D. Einfeld ESRF, Grenoble, France
	The first synchrotron radiation was used in a so called parasitic mode from high energy machines (1st generation). At the end of the 1970s and the beginning of 1980s accelerators dedicated to the production of synchrotron radiation were built (2nd generations). With the investigation and developments of insertion devices in the middle of 1980, the 3rd generation synchrotron radiation sources were built and emittances down to some nmrad could be reached. At present around 50 Synchrotron Radiation sources are existing around the world. All of these sources reached there the specification (energy, current, emittance, beam stability, etc.) very soon after the commissioning. With the 4th generation, emittances of down to around 100 pmrad should be reached. This is still a factor of 10 away from the requirement of a diffraction limited light source. According to the expertise in designing and operating of synchrotron radiation sources this should be reachable in the future, but only with circumferences of some kilometers like Petra III or PEP-X. Overall the performances and perspective of synchrotron light source are remarkable.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-MOOTH4
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MOT3AH2	Higgs Factory Concepts	ion, collider, luminosity, operation	25
	F. Zimmermann CERN, Geneva, Switzerland
	Funding: This work was supported in part by the European Commission under the FP7 Capacities project EuCARD-2, grant agreement 312453. Designs for future high-energy circular electron-positron colliders are based on both established and novel concepts. An appropriate design will allow these facilities to serve not only as ‘‘Higgs factories'', but also as Z, W and top factories, and, in addition, to become a possible first step to a higher-energy hadron collider.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-MOT3AH2
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TUT1AH3	The FCC-ee Interaction Region Magnet Design	ion, solenoid, quadrupole, detector	57
	M. Koratzinos DPNC, Genève, Switzerland
	The design of the region close to the interaction point of the FCC-ee experiments is especially challenging. The beams collide at an angle (±15 mrad) in the high-field region of the detector solenoid. Moreover, the very low vertical beta' of the machine necessitates that the final focusing quadrupoles have a distance from the IP (L') of around 2 m and therefore are inside the main detector solenoid. The beams should be screened from the effect of the detector magnetic field, and the emittance blow-up due to vertical dispersion in the interaction region should be minimized, while leaving enough space for detector components. Crosstalk between the two final focus quadrupoles, only about 6 cm apart at the tip, should also be eliminated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT1AH3
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TUT1BH2	Study of Coherent Head-tail Instablility Due to Beam-beam Interaction in Cirular Colliders Based on Crab Waist Scheme	ion, simulation, luminosity, damping	61
	K. Ohmi KEK, Ibaraki, Japan
	FCC-ee is being studied various collision schemes, head-on and large Piwinski angle/ crab waist schemes. We discuss beam-beam limit in the collision schemes using weak-strong and strong-strong models.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT1BH2
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TUT2H2	Injector Linac Upgrade and New RF Gun Development for SuperKEKB	ion, gun, cavity, laser	74
	T. Natsui, D. Satoh, M. Yoshida, R. Zhang, X. Zhou KEK, Ibaraki, Japan
	The SuperKEKB commissioning has finally started. The final goal of luminosity is 40 times higher than KEKB. The injector upgrade is required to obtain the low emittance and high charge beam corresponding to the short beam life and small injection acceptance of the SuperKEKB ring. In the injector linac, several new instruments have been installed. Flux Concentrator (FC) was developed for high charge positron beam production. The target bunch charge of positron beam is 4 nC. The new damping ring will be used for positron beam to reduce beam emittance to 10 mm-mrad. However, electron beam must be reached to 20 mm-mrad normalized emittance at 5 nC beam charge without damping ring. Thermionic gun was used for KEKB injector and it was able to generate enough beam charge. However, its emittance is too large. Therefor we developed photo cathode S-band RF gun. This new RF gun has unique accelerating cavity which called quasi-travelling wave side coupled cavity. Laser system for this photo cathode has been also developed. The laser system is constructed with Yb:YAG thin disk for high power and pulse shaping. I will illustrate the RF gun, laser system and several new injector linac systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT2H2
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TUT2H5	Towards a Preliminary FCC-ee Injector Design	ion, linac, positron, damping	90
	S. Ogur, Y. Papaphilippou, F. Zimmermann CERN, Geneva, Switzerland A.M. Barnyakov, A.E. Levichev, D.A. Nikiforov BINP SB RAS, Novosibirsk, Russia K. Furukawa, N. Iida, F. Miyahara, K. Oide KEK, Ibaraki, Japan
	The Future Circular Collider-ee aims to get high luminosity which mainly relies upon high charge and low geometric emittance in the collider. The FCC-ee is a future project of CERN to operate as Z, W, H and tt factories with varying energies between 45.6 to 175 GeV. Among those, the total charge requirement is peaked for Z-operation (i.e. 91500 bunches of electron and positron with 3.3·10¹⁰ particles per bunch) meanwhile this mode targets the smallest geometric emittance in the Collider. To reach the goal, the normal conducting S-band Linac has been designed to accelerate 4·10¹⁰ particles in a bunch to 6 GeV and send two bunches per RF pulse within a repetition of 100 Hz. The FCC-ee positrons will also be created inside the linac at 4.46 GeV and accelerated to 1.54 GeV. These positrons are damped at the designed Damping Ring at that energy, and then transferred back to the Linac to meet the same characteristics of electrons. Therefore, in this paper, we'd like to discuss the transmission and robustness of the Linac and the dynamic aperture of the Damping Ring which has to be large enough to accept the incoming beam and cover the probable shrink due to the misalignments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT2H5
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TUT3BH2	Optics Correction and Low Emittance Tuning at the Phase 1 commissioning of SuperKEKB	ion, sextupole, optics, coupling	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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TUT3BH4	Coupling and Dispersion Correction for the Tolerance Study in FCC-ee	ion, coupling, 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, coupling	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

MOOTH2

Commissioning of SuperKEKB

ion, MMI, vacuum, detector

4

Y. Funakoshi
KEK, Ibaraki, Japan

After 5 years of upgrade work from KEKB, the Phase 1 beam commissioning of SuperKEKB started on Feb. 1st this year and finished at the end of June. In Phase 1, Belle-II detector and the final focus doublet (QCS) were not installed and no beam collision was performed. Missions of the commissioning in Phase 1 were startup of each hardware component, establishment of beam operation software tools, preparation of Belle-II detector, an optics study and tuning without QCS and the detector solenoid magnet and other machine studies. In this talk, achievements in the Phase 1 commissioning are summarized. Also a plan for the Phase 2 commissioning will be given.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-MOOTH2

Export •

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

MOOTH4

Performance and Perspective of Modern Synchrotron Light Sources

ion, synchrotron, lattice, SRF

17

D. Einfeld
ESRF, Grenoble, France

The first synchrotron radiation was used in a so called parasitic mode from high energy machines (1st generation). At the end of the 1970s and the beginning of 1980s accelerators dedicated to the production of synchrotron radiation were built (2nd generations). With the investigation and developments of insertion devices in the middle of 1980, the 3rd generation synchrotron radiation sources were built and emittances down to some nmrad could be reached. At present around 50 Synchrotron Radiation sources are existing around the world. All of these sources reached there the specification (energy, current, emittance, beam stability, etc.) very soon after the commissioning. With the 4th generation, emittances of down to around 100 pmrad should be reached. This is still a factor of 10 away from the requirement of a diffraction limited light source. According to the expertise in designing and operating of synchrotron radiation sources this should be reachable in the future, but only with circumferences of some kilometers like Petra III or PEP-X. Overall the performances and perspective of synchrotron light source are remarkable.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-MOOTH4

Export •

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

MOT3AH2

Higgs Factory Concepts

ion, collider, luminosity, operation

25

F. Zimmermann
CERN, Geneva, Switzerland

Funding: This work was supported in part by the European Commission under the FP7 Capacities project EuCARD-2, grant agreement 312453.
Designs for future high-energy circular electron-positron colliders are based on both established and novel concepts. An appropriate design will allow these facilities to serve not only as ‘‘Higgs factories'', but also as Z, W and top factories, and, in addition, to become a possible first step to a higher-energy hadron collider.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-MOT3AH2

Export •

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

TUT1AH3

The FCC-ee Interaction Region Magnet Design

ion, solenoid, quadrupole, detector

57

M. Koratzinos
DPNC, Genève, Switzerland

The design of the region close to the interaction point of the FCC-ee experiments is especially challenging. The beams collide at an angle (±15 mrad) in the high-field region of the detector solenoid. Moreover, the very low vertical beta' of the machine necessitates that the final focusing quadrupoles have a distance from the IP (L') of around 2 m and therefore are inside the main detector solenoid. The beams should be screened from the effect of the detector magnetic field, and the emittance blow-up due to vertical dispersion in the interaction region should be minimized, while leaving enough space for detector components. Crosstalk between the two final focus quadrupoles, only about 6 cm apart at the tip, should also be eliminated.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT1AH3

Export •

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

TUT1BH2

Study of Coherent Head-tail Instablility Due to Beam-beam Interaction in Cirular Colliders Based on Crab Waist Scheme

ion, simulation, luminosity, damping

61

K. Ohmi
KEK, Ibaraki, Japan

FCC-ee is being studied various collision schemes, head-on and large Piwinski angle/ crab waist schemes. We discuss beam-beam limit in the collision schemes using weak-strong and strong-strong models.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT1BH2

Export •

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

TUT2H2

Injector Linac Upgrade and New RF Gun Development for SuperKEKB

ion, gun, cavity, laser

74

T. Natsui, D. Satoh, M. Yoshida, R. Zhang, X. Zhou
KEK, Ibaraki, Japan

The SuperKEKB commissioning has finally started. The final goal of luminosity is 40 times higher than KEKB. The injector upgrade is required to obtain the low emittance and high charge beam corresponding to the short beam life and small injection acceptance of the SuperKEKB ring. In the injector linac, several new instruments have been installed. Flux Concentrator (FC) was developed for high charge positron beam production. The target bunch charge of positron beam is 4 nC. The new damping ring will be used for positron beam to reduce beam emittance to 10 mm-mrad. However, electron beam must be reached to 20 mm-mrad normalized emittance at 5 nC beam charge without damping ring. Thermionic gun was used for KEKB injector and it was able to generate enough beam charge. However, its emittance is too large. Therefor we developed photo cathode S-band RF gun. This new RF gun has unique accelerating cavity which called quasi-travelling wave side coupled cavity. Laser system for this photo cathode has been also developed. The laser system is constructed with Yb:YAG thin disk for high power and pulse shaping. I will illustrate the RF gun, laser system and several new injector linac systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT2H2

Export •

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

TUT2H5

Towards a Preliminary FCC-ee Injector Design

ion, linac, positron, damping

90

S. Ogur, Y. Papaphilippou, F. Zimmermann
CERN, Geneva, Switzerland
A.M. Barnyakov, A.E. Levichev, D.A. Nikiforov
BINP SB RAS, Novosibirsk, Russia
K. Furukawa, N. Iida, F. Miyahara, K. Oide
KEK, Ibaraki, Japan

The Future Circular Collider-ee aims to get high luminosity which mainly relies upon high charge and low geometric emittance in the collider. The FCC-ee is a future project of CERN to operate as Z, W, H and tt factories with varying energies between 45.6 to 175 GeV. Among those, the total charge requirement is peaked for Z-operation (i.e. 91500 bunches of electron and positron with 3.3·10¹⁰ particles per bunch) meanwhile this mode targets the smallest geometric emittance in the Collider. To reach the goal, the normal conducting S-band Linac has been designed to accelerate 4·10¹⁰ particles in a bunch to 6 GeV and send two bunches per RF pulse within a repetition of 100 Hz. The FCC-ee positrons will also be created inside the linac at 4.46 GeV and accelerated to 1.54 GeV. These positrons are damped at the designed Damping Ring at that energy, and then transferred back to the Linac to meet the same characteristics of electrons. Therefore, in this paper, we'd like to discuss the transmission and robustness of the Linac and the dynamic aperture of the Damping Ring which has to be large enough to accept the incoming beam and cover the probable shrink due to the misalignments.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2016-TUT2H5

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, optics, coupling

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)

TUT3BH4

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

ion, coupling, 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, coupling

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)