IPAC2015 - List of Authors (Wienands, U.)

Paper	Title	Page
MOPHA054	Interaction Point Orbit Feedback System at SuperKEKB	921
	Y. Funakoshi, H. Fukuma, T. Kawamoto, M. Masuzawa, T. Oki, S. Uehara, H. Yamaoka KEK, Ibaraki, Japan S.D. Anderson, S.M. Gierman, M. Kosovsky, J.T. Seeman, C.M. Spencer, M.K. Sullivan, O. Turgut, U. Wienands SLAC, Menlo Park, California, USA P. Bambade, D. El Khechen, D. Jehanno, V. Kubytskyi, C. Rimbault LAL, Orsay, France
	In order to maintain an optimum beam collision condition in a double ring collider such as SuperKEKB it is essential to have an orbit feedback system at the interaction point (IP). We have designed such a system based on experiences at KEKB and PEP-II. For the vertical offset and crossing angle, we will rely on the system based on the beam orbit measurement similar to that used at KEKB. For the horizontal offset, however, we will utilize the dithering system which was successfully used at PEP-II, because the horizontal beam-beam kick is very weak with the "nano-beam scheme". Some hardware devices have been already fabricated and others are in preparation. The present status of the development is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA054
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TUYB3	Progress on the Design of the Polarized Medium-energy Electron Ion Collider at JLab	1302
	F. Lin, S.A. Bogacz, P.D. Brindza, A. Camsonne, E. Daly, Y.S. Derbenev, D. Douglas, R. Ent, D. Gaskell, R.L. Geng, J.M. Grames, J. Guo, L. Harwood, A. Hutton, K. Jordan, A.J. Kimber, G.A. Krafft, R. Li, T.J. Michalski, V.S. Morozov, P. Nadel-Turonski, F.C. Pilat, M. Poelker, R.A. Rimmer, Y. Roblin, T. Satogata, M. Spata, R. Suleiman, A.V. Sy, C. Tennant, H. Wang, S. Wang, H. Zhang, Y. Zhang, Z.W. Zhao JLab, Newport News, Virginia, USA S. Abeyratne, B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA D.P. Barber DESY, Hamburg, Germany Y. Cai, Y. Nosochkov, M.K. Sullivan, M.-H. Wang, U. Wienands SLAC, Menlo Park, California, USA A. Castilla, J.R. Delayen ODU, Norfolk, Virginia, USA Y. Filatov JINR, Dubna, Russia J. Gerity, T.L. Mann, P.M. McIntyre, N. Pogue, A. Sattarov Texas A&M University, College Station, Texas, USA C. Hyde, K. Park Old Dominion University, Norfolk, Virginia, USA A.M. Kondratenko, M.A. Kondratenko Science and Technique Laboratory Zaryad, Novosibirsk, Russia P.N. Ostroumov ANL, Argonne, Illinois, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. The Medium-energy Electron Ion Collider (MEIC) at JLab is designed to provide high luminosity and high polarization needed to reach new frontiers in the exploration of nuclear structure. The luminosity, exceeding 1033 cm^-2s⁻¹ in a broad range of the center-of-mass (CM) energy and maximum luminosity above 1034 cm^-2s⁻¹, is achieved by high-rate collisions of short small-emittance low-charge bunches made possible by high-energy electron cooling of the ion beam and synchrotron radiation damping of the electron beam. The polarization of light ion species (p, d, 3He) can be easily preserved and manipulated due to the unique figure-8 shape of the collider rings. A fully consistent set of parameters have been developed considering the balance of machine performance, required technical development and cost. This paper reports recent progress on the MEIC accelerator design including electron and ion complexes, integrated interaction region design, figure-8-ring-based electron and ion polarization schemes, RF/SRF systems and ERL-based high-energy electron cooling. Luminosity performance is also presented for the MEIC baseline design.
	Slides TUYB3 [6.245 MB]
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TUPTY060	The FCC-ee Study: Progress and Challenges	2165
	M. Koratzinos DPNC, Genève, Switzerland S. Aumon, C. Cook, A. Doblhammer, B. Härer, B.J. Holzer, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland A.V. Bogomyagkov, E.B. Levichev, D.N. Shatilov BINP SB RAS, Novosibirsk, Russia M. Boscolo INFN/LNF, Frascati (Roma), Italy L.E. Medina Medrano UGTO, Leon, Mexico U. Wienands SLAC, Menlo Park, California, USA
	The FCC (future circular collider) study represents a vision for the next large project in high energy physics, comprising a 80-100 km tunnel that can house a future 100TeV hadron collider. The study also includes a high luminosity e⁺e⁻ collider operating in the centre-of-mass energy range of 90-350 GeV as a possible intermediate step, the FCC-ee. The FCC-ee aims at definitive electro-weak precision measurements of the Z, W, H and top particles, and search for rare phenomena. Although FCC-ee is based on known technology, the goal performance in luminosity and energy calibration make it quite challenging. During 2014 the study went through an exploration phase and during the next three years a conceptual design report will be prepared.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY060
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TUPTY061	Combined Operation and Staging Scenarios for the FCC-ee Lepton Collider	2169
	M. Benedikt, B.J. Holzer, E. Jensen, R. Tomás, J. Wenninger, F. Zimmermann CERN, Geneva, Switzerland A.V. Bogomyagkov, E.B. Levichev, D.N. Shatilov BINP SB RAS, Novosibirsk, Russia K. Ohmi, K. Oide KEK, Ibaraki, Japan U. Wienands SLAC, Menlo Park, California, USA
	FCC-ee is a proposed high-energy electron positron circular collider that would initially occupy the 100-km FCC tunnel that will eventually house the 100 TeV FCC-hh hadron collider. The parameter range for the e⁺/e⁻ collider is large, operating at a cm energy from 90 GeV (Z-pole) to 350 GeV (t-tbar production) with the maximum beam current ranging from 1.5 A to 6 mA for each beam, corresponding to a synchrotron radiation power of 50 MW and a radiative energy loss varying from ~30 MeV/turn to ~7500 MeV/turn. This presents challenges for the rf system due to the varying rf voltage requirements and beam loading conditions. In this paper we present a possible gradual evolution of the FCC-ee complex by step-wise expansion, and possibly reconfiguration, of the superconducting RF system. The performance attainable at each step is discussed, along with the possible advantages and drawbacks.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY061
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TUPTY084	Update on the MEIC Electron Collider Ring Design	2236
	F. Lin, Y.S. Derbenev, L. Harwood, A. Hutton, V.S. Morozov, F.C. Pilat, Y. Zhang JLab, Newport News, Virginia, USA Y. Cai, Y. Nosochkov, M.K. Sullivan, M.-H. Wang, U. Wienands SLAC, Menlo Park, California, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work also supported by the U.S. DOE Contract No. DE-AC02-76SF00515. The electron collider ring of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab is designed to accumulate and store a high-current polarized electron beam for collisions with an ion beam. We consider a design of the electron collider ring based on reusing PEP-II components, such as magnets, power supplies, vacuum system, etc. This has the potential to significantly reduce the cost and engineering effort needed to bring the project to fruition. This paper reports on an electron ring optics design considering the balance of PEP-II hardware parameters (such as dipole sagitta, magnet field strengths and acceptable synchrotron radiation power) and electron beam quality in terms of equilibrium emittances.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY084
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TUPWI031	Status of the MEIC Ion Collider Ring Design	2307
	V.S. Morozov, Y.S. Derbenev, L. Harwood, A. Hutton, F. Lin, F.C. Pilat, Y. Zhang JLab, Newport News, Virginia, USA Y. Cai, Y. Nosochkov, M.K. Sullivan, M.-H. Wang, U. Wienands SLAC, Menlo Park, California, USA J. Gerity, T.L. Mann, P.M. McIntyre, N. Pogue, A. Sattarov Texas A&M University, College Station, Texas, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported in part by the US DOE Contract No. DE-AC02-76SF00515. We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI031
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TUPWI032	Progress on Optimization of the Nonlinear Beam Dynamics in the MEIC Collider Rings	2311
	Y. Nosochkov, Y. Cai, M.K. Sullivan, M.-H. Wang, U. Wienands SLAC, Menlo Park, California, USA Y.S. Derbenev, F. Lin, V.S. Morozov, F.C. Pilat, Y. Zhang JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under US DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported by the US DOE Contract DE-AC02-76SF00515. One of the key design features of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab is a small beta function at the interaction point (IP) allowing one to achieve a high luminosity of up to 10³⁴ cm^-2s^-1. The required strong beam focusing unavoidably causes large chromatic effects such as chromatic tune spread and beam smear at the IP, which need to be compensated. This paper reports recent progress in our development of a chromaticity correction scheme for the ion ring including optimization of dynamic aperture and momentum acceptance.
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WEPWI006	Dither Coils for the SuperKEKB Fast Collision Feedback System	3500
	U. Wienands, S.D. Anderson, S.M. Gierman, M. Kosovsky, C.M. Spencer, M.K. Sullivan SLAC, Menlo Park, California, USA Y. Funakoshi, M. Masuzawa, T. Oki KEK, Ibaraki, Japan
	Funding: Work supported in part by US DOE and in part by the US-Japan collaboration agreement. The collision feedback system for the SuperKEKB electron-positron collider at KEK will employ a dither feedback with a roughly 100 Hz excitation frequency to generate a signal proportional to the offset of the two beams. The excitation will be provided by a local bump across the interaction point (IP) that is generated by a set of eight air-core solid-wire magnet coil assemblies, each of which provides a horizontal and/or vertical deflection of the beam, to be installed around the vacuum system of the SuperKEKB Low Energy Ring. The design of the coils was challenging as large antechambers had to be accommodated and a 0.1% relative field uniformity across a good-field region of ±1 cm was aimed for, while keeping reasonable dimensions of the coils. This led to non-symmetric, non-flat designs of the coils. The paper describes the magnetic design and the method used to calculate the magnetic field of the coils, the mechanical design and the field measurement results. Tracking in the lattice model has indicated acceptable performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI006
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Paper

Title

Page

Interaction Point Orbit Feedback System at SuperKEKB

921

Y. Funakoshi, H. Fukuma, T. Kawamoto, M. Masuzawa, T. Oki, S. Uehara, H. Yamaoka
KEK, Ibaraki, Japan
S.D. Anderson, S.M. Gierman, M. Kosovsky, J.T. Seeman, C.M. Spencer, M.K. Sullivan, O. Turgut, U. Wienands
SLAC, Menlo Park, California, USA
P. Bambade, D. El Khechen, D. Jehanno, V. Kubytskyi, C. Rimbault
LAL, Orsay, France

In order to maintain an optimum beam collision condition in a double ring collider such as SuperKEKB it is essential to have an orbit feedback system at the interaction point (IP). We have designed such a system based on experiences at KEKB and PEP-II. For the vertical offset and crossing angle, we will rely on the system based on the beam orbit measurement similar to that used at KEKB. For the horizontal offset, however, we will utilize the dithering system which was successfully used at PEP-II, because the horizontal beam-beam kick is very weak with the "nano-beam scheme". Some hardware devices have been already fabricated and others are in preparation. The present status of the development is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA054

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TUYB3

Progress on the Design of the Polarized Medium-energy Electron Ion Collider at JLab

1302

F. Lin, S.A. Bogacz, P.D. Brindza, A. Camsonne, E. Daly, Y.S. Derbenev, D. Douglas, R. Ent, D. Gaskell, R.L. Geng, J.M. Grames, J. Guo, L. Harwood, A. Hutton, K. Jordan, A.J. Kimber, G.A. Krafft, R. Li, T.J. Michalski, V.S. Morozov, P. Nadel-Turonski, F.C. Pilat, M. Poelker, R.A. Rimmer, Y. Roblin, T. Satogata, M. Spata, R. Suleiman, A.V. Sy, C. Tennant, H. Wang, S. Wang, H. Zhang, Y. Zhang, Z.W. Zhao
JLab, Newport News, Virginia, USA
S. Abeyratne, B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA
D.P. Barber
DESY, Hamburg, Germany
Y. Cai, Y. Nosochkov, M.K. Sullivan, M.-H. Wang, U. Wienands
SLAC, Menlo Park, California, USA
A. Castilla, J.R. Delayen
ODU, Norfolk, Virginia, USA
Y. Filatov
JINR, Dubna, Russia
J. Gerity, T.L. Mann, P.M. McIntyre, N. Pogue, A. Sattarov
Texas A&M University, College Station, Texas, USA
C. Hyde, K. Park
Old Dominion University, Norfolk, Virginia, USA
A.M. Kondratenko, M.A. Kondratenko
Science and Technique Laboratory Zaryad, Novosibirsk, Russia
P.N. Ostroumov
ANL, Argonne, Illinois, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
The Medium-energy Electron Ion Collider (MEIC) at JLab is designed to provide high luminosity and high polarization needed to reach new frontiers in the exploration of nuclear structure. The luminosity, exceeding 1033 cm^-2s⁻¹ in a broad range of the center-of-mass (CM) energy and maximum luminosity above 1034 cm^-2s⁻¹, is achieved by high-rate collisions of short small-emittance low-charge bunches made possible by high-energy electron cooling of the ion beam and synchrotron radiation damping of the electron beam. The polarization of light ion species (p, d, 3He) can be easily preserved and manipulated due to the unique figure-8 shape of the collider rings. A fully consistent set of parameters have been developed considering the balance of machine performance, required technical development and cost. This paper reports recent progress on the MEIC accelerator design including electron and ion complexes, integrated interaction region design, figure-8-ring-based electron and ion polarization schemes, RF/SRF systems and ERL-based high-energy electron cooling. Luminosity performance is also presented for the MEIC baseline design.

Slides TUYB3 [6.245 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUYB3

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TUPTY060

The FCC-ee Study: Progress and Challenges

2165

M. Koratzinos
DPNC, Genève, Switzerland
S. Aumon, C. Cook, A. Doblhammer, B. Härer, B.J. Holzer, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
A.V. Bogomyagkov, E.B. Levichev, D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia
M. Boscolo
INFN/LNF, Frascati (Roma), Italy
L.E. Medina Medrano
UGTO, Leon, Mexico
U. Wienands
SLAC, Menlo Park, California, USA

The FCC (future circular collider) study represents a vision for the next large project in high energy physics, comprising a 80-100 km tunnel that can house a future 100TeV hadron collider. The study also includes a high luminosity e⁺e⁻ collider operating in the centre-of-mass energy range of 90-350 GeV as a possible intermediate step, the FCC-ee. The FCC-ee aims at definitive electro-weak precision measurements of the Z, W, H and top particles, and search for rare phenomena. Although FCC-ee is based on known technology, the goal performance in luminosity and energy calibration make it quite challenging. During 2014 the study went through an exploration phase and during the next three years a conceptual design report will be prepared.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY060

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TUPTY061

Combined Operation and Staging Scenarios for the FCC-ee Lepton Collider

2169

M. Benedikt, B.J. Holzer, E. Jensen, R. Tomás, J. Wenninger, F. Zimmermann
CERN, Geneva, Switzerland
A.V. Bogomyagkov, E.B. Levichev, D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia
K. Ohmi, K. Oide
KEK, Ibaraki, Japan
U. Wienands
SLAC, Menlo Park, California, USA

FCC-ee is a proposed high-energy electron positron circular collider that would initially occupy the 100-km FCC tunnel that will eventually house the 100 TeV FCC-hh hadron collider. The parameter range for the e⁺/e⁻ collider is large, operating at a cm energy from 90 GeV (Z-pole) to 350 GeV (t-tbar production) with the maximum beam current ranging from 1.5 A to 6 mA for each beam, corresponding to a synchrotron radiation power of 50 MW and a radiative energy loss varying from ~30 MeV/turn to ~7500 MeV/turn. This presents challenges for the rf system due to the varying rf voltage requirements and beam loading conditions. In this paper we present a possible gradual evolution of the FCC-ee complex by step-wise expansion, and possibly reconfiguration, of the superconducting RF system. The performance attainable at each step is discussed, along with the possible advantages and drawbacks.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY061

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TUPTY084

Update on the MEIC Electron Collider Ring Design

2236

F. Lin, Y.S. Derbenev, L. Harwood, A. Hutton, V.S. Morozov, F.C. Pilat, Y. Zhang
JLab, Newport News, Virginia, USA
Y. Cai, Y. Nosochkov, M.K. Sullivan, M.-H. Wang, U. Wienands
SLAC, Menlo Park, California, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work also supported by the U.S. DOE Contract No. DE-AC02-76SF00515.
The electron collider ring of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab is designed to accumulate and store a high-current polarized electron beam for collisions with an ion beam. We consider a design of the electron collider ring based on reusing PEP-II components, such as magnets, power supplies, vacuum system, etc. This has the potential to significantly reduce the cost and engineering effort needed to bring the project to fruition. This paper reports on an electron ring optics design considering the balance of PEP-II hardware parameters (such as dipole sagitta, magnet field strengths and acceptable synchrotron radiation power) and electron beam quality in terms of equilibrium emittances.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY084

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TUPWI031

Status of the MEIC Ion Collider Ring Design

2307

V.S. Morozov, Y.S. Derbenev, L. Harwood, A. Hutton, F. Lin, F.C. Pilat, Y. Zhang
JLab, Newport News, Virginia, USA
Y. Cai, Y. Nosochkov, M.K. Sullivan, M.-H. Wang, U. Wienands
SLAC, Menlo Park, California, USA
J. Gerity, T.L. Mann, P.M. McIntyre, N. Pogue, A. Sattarov
Texas A&M University, College Station, Texas, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported in part by the US DOE Contract No. DE-AC02-76SF00515.
We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI031

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TUPWI032

Progress on Optimization of the Nonlinear Beam Dynamics in the MEIC Collider Rings

2311

Y. Nosochkov, Y. Cai, M.K. Sullivan, M.-H. Wang, U. Wienands
SLAC, Menlo Park, California, USA
Y.S. Derbenev, F. Lin, V.S. Morozov, F.C. Pilat, Y. Zhang
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under US DOE Contract No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported by the US DOE Contract DE-AC02-76SF00515.
One of the key design features of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab is a small beta function at the interaction point (IP) allowing one to achieve a high luminosity of up to 10³⁴ cm^-2s^-1. The required strong beam focusing unavoidably causes large chromatic effects such as chromatic tune spread and beam smear at the IP, which need to be compensated. This paper reports recent progress in our development of a chromaticity correction scheme for the ion ring including optimization of dynamic aperture and momentum acceptance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPWI032

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WEPWI006

Dither Coils for the SuperKEKB Fast Collision Feedback System

3500

U. Wienands, S.D. Anderson, S.M. Gierman, M. Kosovsky, C.M. Spencer, M.K. Sullivan
SLAC, Menlo Park, California, USA
Y. Funakoshi, M. Masuzawa, T. Oki
KEK, Ibaraki, Japan

Funding: Work supported in part by US DOE and in part by the US-Japan collaboration agreement.
The collision feedback system for the SuperKEKB electron-positron collider at KEK will employ a dither feedback with a roughly 100 Hz excitation frequency to generate a signal proportional to the offset of the two beams. The excitation will be provided by a local bump across the interaction point (IP) that is generated by a set of eight air-core solid-wire magnet coil assemblies, each of which provides a horizontal and/or vertical deflection of the beam, to be installed around the vacuum system of the SuperKEKB Low Energy Ring. The design of the coils was challenging as large antechambers had to be accommodated and a 0.1% relative field uniformity across a good-field region of ±1 cm was aimed for, while keeping reasonable dimensions of the coils. This led to non-symmetric, non-flat designs of the coils. The paper describes the magnetic design and the method used to calculate the magnetic field of the coils, the mechanical design and the field measurement results. Tracking in the lattice model has indicated acceptable performance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI006

Export •

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