IPAC2021 - List of Authors (Smaluk, V.V.)

Paper	Title	Page
MOPAB039	Amplitude-Dependent Shift of Betatron Tunes and Its Relation to Long-Term Circumference Variations at NSLS-II	175
	L.H. Yu, G. Bassi, Y. Hidaka, B. Podobedov, V.V. Smaluk, G.M. Wang, X. Yang BNL, Upton, New York, USA
	The comparison of amplitude tune dependence measured for NSLSII lattices with models indicated the large change of amplitude tune dependence over time apparently can not be solely explained by magnets variation or beta function changes, but it seems can be explained by energy changes. On the other hand, the energy change required by fitting with the amplitude tune dependence change is too large to be explained by the RF frequency change and the change of the sum of correctors in the period of the measurements. To explain this apparent contradiction, our analysis shows the long term storage ring circumference change can explain the apparent energy change. Our data indeed shows a seasonal change of the amplitude tune dependence over long term observation. This clearly also indicated a relation to long term closed orbit drift. Hence the current work indicates a new strategy to study how to use amplitude tune dependence as a guideline to analyze long term lattice parameter shifts and closed orbit drift, and improve the orbit and machine performance stability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB039
About •	paper received ※ 09 May 2021 paper accepted ※ 26 May 2021 issue date ※ 26 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPAB041	Convergence Map with Action-Angle Variables Based on Square Matrix for Nonlinear Lattice Optimization	182
	L.H. Yu, Y. Hidaka, F. Plassard, V.V. Smaluk BNL, Upton, New York, USA Y. Hao FRIB, East Lansing, Michigan, USA
	We apply square matrix method to obtain in high speed a "convergence map", which is similar but different from frequency map. The convergence map is obtained from solving nonlinear dynamical equation by iteration of perturbation method and study the convergence. The map provides information about the stability border of dynamical aperture. We compare the map with frequency map from tracking. The result indicates the new method may be applied in nonlinear lattice optimization, taking the advantage of the high speed (about 10~50 times faster) to explore x, y and the off-momentum phase space.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB041
About •	paper received ※ 09 May 2021 paper accepted ※ 26 May 2021 issue date ※ 18 August 2021
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TUXC06	Visualizing Lattice Dynamic Behavior by Acquiring a Single Time-Resolved MeV	1311
	X. Yang, T.V. Shaftan, V.V. Smaluk, J. Tao, L. Wu, Y. Zhu BNL, Upton, New York, USA W. Wan ShanghaiTech University, Shanghai, People’s Republic of China
	We explore the possibility of visualizing the lattice dynamic behavior by acquiring a single time-resolved MeV UED image. Conventionally, multiple UED shots with varying time delays are needed to map out the entire dynamic process. The measurement precision is limited by the timing jitter between the pulses of laser pump and UED probe. We show that, by converting the longitudinal time of an electron bunch to the transverse position of a Bragg peak on the detector, one can obtain the full lattice dynamic process in a single electron pulse. We propose a novel design of a time-resolved UED with the capability of capturing a wide range of dynamic features in a single diffraction image. The work presented here is not only an extension of the ultrashort-pulse pump/long-pulse probe scheme being used in transient spectroscopy studies for decades but also advances the capabilities of MeV UED for future applications with tunable electron probe profile and detecting time range with femtosecond resolution. Furthermore, we present numerical simulations illustrating the capability of acquiring a single time-resolved diffraction image based on the case-by-case studies of lattice dynamic behavior.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXC06
About •	paper received ※ 14 May 2021 paper accepted ※ 28 July 2021 issue date ※ 31 August 2021
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TUPAB223	Design of Double- and Multi-Bend Achromat Lattices with Large Dynamic Aperture and Approximate Invariants	1945
	Y. Li, R.S. Rainer, V.V. Smaluk BNL, Upton, New York, USA K. Hwang, C.E. Mitchell, R.D. Ryne LBNL, Berkeley, California, USA
	Funding: Funded by U.S. Department of Energy (DOE) under Contract No. DE-SC0012704 (BNL) and DE-AC02-05CH11231 (LBNL), U.S. DOE Early Career Research Program under the Office of High Energy Physics. A numerical method to design nonlinear double- and multi-bend achromat (DBA and MBA) lattices with approximate invariants of motion is described. The search for such nonlinear lattices is motivated by Fermilab’s Integrable Optics Test Accelerator (IOTA), whose design is based on an integrable Hamiltonian system with two invariants of motion. While it may not be possible to design an achromatic lattice for a dedicated synchrotron light source storage ring with one or more exact invariants of motion, it is possible to tune the sextupoles and octupoles in existing DBA and MBA lattices to produce approximate invariants. In our procedure, the lattice is tuned while minimizing the turn-by-turn fluctuations of the Courant-Snyder actions Jx and Jy at several distinct amplitudes, while simultaneously minimizing diffusion of the on-energy betatron tunes. The resulting lattices share some important features with integrable ones, such as a large dynamic aperture, trajectories confined to invariant tori, robustness to resonances and errors, and a large amplitude-dependent tune-spread.
	Poster TUPAB223 [2.392 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB223
About •	paper received ※ 10 May 2021 paper accepted ※ 15 June 2021 issue date ※ 20 August 2021
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TUPAB227	Simultaneous Compensation of Phase and Amplitude Dependent Geometrical Resonances Using Octupoles	1960
	F. Plassard, Y. Hidaka, Y. Li, T.V. Shaftan, V.V. Smaluk, G.M. Wang BNL, Upton, New York, USA
	As the new generation of light sources are pushing toward diffraction limited storage rings with ultra-low emittance beams, nonlinear beam dynamics become increasingly difficult to control. It is a common practice for modern designs to use a sextupole scheme that allows simultaneous correction of natural chromaticity and energy independent, or geometrical, sextupolar resonances. However, the remaining higher order terms arising from the cross talks of the sextupole families set a strong limitation on the achievable dynamic aperture. This paper presents a simulation-based recipe to use octupoles together with this sextupole scheme to provide simultaneous self-compensation of linear amplitude dependent tune shift together with phase-dependent octupolar and higher order geometrical resonant driving terms. The correction method was built based on observations made on a simple FODO model, then applied to a realistic low emittance lattice, designed in the framework of the upgrade of the National Synchrotron Light Source II (NSLS-II).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB227
About •	paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 14 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPAB005	Design Status Update of the Electron-Ion Collider	2585
	C. Montag, E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, Z.A. Conway, K.A. Drees, A.V. Fedotov, W. Fischer, C. Folz, D.M. Gassner, X. Gu, R.C. Gupta, Y. Hao, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, M. Mapes, D. Marx, G.T. McIntyre, F. Méot, M.G. Minty, S.K. Nayak, R.B. Palmer, B. Parker, S. Peggs, B. Podobedov, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, S. Verdú-Andrés, E. Wang, D. Weiss, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang BNL, Upton, New York, USA S.V. Benson, J.M. Grames, F. Lin, T.J. Michalski, V.S. Morozov, E.A. Nissen, J.P. Preble, R.A. Rimmer, T. Satogata, A. Seryi, M. Wiseman, W. Wittmer, Y. Zhang JLab, Newport News, Virginia, USA Y. Cai, Y.M. Nosochkov, G. Stupakov, M.K. Sullivan SLAC, Menlo Park, California, USA K.E. Deitrick, C.M. Gulliford, G.H. Hoffstaetter, J.E. Unger Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA T. Satogata ODU, Norfolk, Virginia, USA D. Xu FRIB, East Lansing, Michigan, USA
	Funding: Work supported by BSA, LLC under Contract No. DE-SC0012704, by JSA, LLC under Contract No. DE-AC05-06OR23177, and by SLAC under Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy. The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community in the White Paper. Over the past year activities have been focused on maturing the design, and on developing alternatives to mitigate risk. These include improvements of the interaction region design as well as modifications of the hadron ring vacuum system to accommodate the high average and peak beam currents. Beam dynamics studies have been performed to determine and optimize the dynamic aperture in the two collider rings and the beam-beam performance. We will present the EIC design with a focus on recent developments.
	Poster WEPAB005 [2.095 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB005
About •	paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 16 August 2021
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WEPAB239	Effect of Chromaticity and Feedback on Transverse Head-Tail Instability	3189
	V.V. Smaluk, G. Bassi, A. Blednykh, A. Khan BNL, Upton, New York, USA
	Funding: This work was supported by the US Department of Energy under contract DE-SC0012704. The head-tail instability caused by the beam interaction with short-range wakefields is a major limitation for the single-bunch beam intensity in circular accelerators. The combined effect of the transverse feedback systems and chromaticity suppressing the instability is discussed. Theoretical and experimental studies of the head-tail instability and methods of its mitigation are reviewed. Results of experimental studies of the transverse mode coupling carried out at NSLS-II are compared with the theoretical model and numerical simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB239
About •	paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 12 August 2021
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THPAB240	Combined Effect of IBS and Impedance on the Longitudinal Beam Dynamics	4274
	A. Blednykh Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA B. Bacha, G. Bassi, T.V. Shaftan, V.V. Smaluk BNL, Upton, New York, USA M. Borland, R.R. Lindberg ANL, Lemont, Illinois, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The horizontal/vertical emittances, the bunch length, and the energy spread increase have been studied in the NSLS-II as a function of a single bunch current. The monotonic growth of the horizontal emittance dependence and the energy spread dependence on the single bunch current below the microwave instability threshold can be explained by the Intrabeam Scattering Effect (IBS). The IBS effect results in an increase in the bunch length and the microwave instability thresholds. It was observed experimentally by varying the vertical emittance. To compare with experimental data, particle tracking simulations have been performed with the ELEGANT code including both IBS and the total longitudinal wakefield calculated from the 3D electromagnetic code GdfidL. The same particle tracking simulations have also been applied for the APS-U project, where IBS is predicted to produce only a marginal effect.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB240
About •	paper received ※ 20 May 2021 paper accepted ※ 05 July 2021 issue date ※ 14 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Amplitude-Dependent Shift of Betatron Tunes and Its Relation to Long-Term Circumference Variations at NSLS-II

175

L.H. Yu, G. Bassi, Y. Hidaka, B. Podobedov, V.V. Smaluk, G.M. Wang, X. Yang
BNL, Upton, New York, USA

The comparison of amplitude tune dependence measured for NSLSII lattices with models indicated the large change of amplitude tune dependence over time apparently can not be solely explained by magnets variation or beta function changes, but it seems can be explained by energy changes. On the other hand, the energy change required by fitting with the amplitude tune dependence change is too large to be explained by the RF frequency change and the change of the sum of correctors in the period of the measurements. To explain this apparent contradiction, our analysis shows the long term storage ring circumference change can explain the apparent energy change. Our data indeed shows a seasonal change of the amplitude tune dependence over long term observation. This clearly also indicated a relation to long term closed orbit drift. Hence the current work indicates a new strategy to study how to use amplitude tune dependence as a guideline to analyze long term lattice parameter shifts and closed orbit drift, and improve the orbit and machine performance stability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB039

About •

paper received ※ 09 May 2021 paper accepted ※ 26 May 2021 issue date ※ 26 August 2021

Export •

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

MOPAB041

Convergence Map with Action-Angle Variables Based on Square Matrix for Nonlinear Lattice Optimization

182

L.H. Yu, Y. Hidaka, F. Plassard, V.V. Smaluk
BNL, Upton, New York, USA
Y. Hao
FRIB, East Lansing, Michigan, USA

We apply square matrix method to obtain in high speed a "convergence map", which is similar but different from frequency map. The convergence map is obtained from solving nonlinear dynamical equation by iteration of perturbation method and study the convergence. The map provides information about the stability border of dynamical aperture. We compare the map with frequency map from tracking. The result indicates the new method may be applied in nonlinear lattice optimization, taking the advantage of the high speed (about 10~50 times faster) to explore x, y and the off-momentum phase space.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB041

About •

paper received ※ 09 May 2021 paper accepted ※ 26 May 2021 issue date ※ 18 August 2021

Export •

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

TUXC06

Visualizing Lattice Dynamic Behavior by Acquiring a Single Time-Resolved MeV

1311

X. Yang, T.V. Shaftan, V.V. Smaluk, J. Tao, L. Wu, Y. Zhu
BNL, Upton, New York, USA
W. Wan
ShanghaiTech University, Shanghai, People’s Republic of China

We explore the possibility of visualizing the lattice dynamic behavior by acquiring a single time-resolved MeV UED image. Conventionally, multiple UED shots with varying time delays are needed to map out the entire dynamic process. The measurement precision is limited by the timing jitter between the pulses of laser pump and UED probe. We show that, by converting the longitudinal time of an electron bunch to the transverse position of a Bragg peak on the detector, one can obtain the full lattice dynamic process in a single electron pulse. We propose a novel design of a time-resolved UED with the capability of capturing a wide range of dynamic features in a single diffraction image. The work presented here is not only an extension of the ultrashort-pulse pump/long-pulse probe scheme being used in transient spectroscopy studies for decades but also advances the capabilities of MeV UED for future applications with tunable electron probe profile and detecting time range with femtosecond resolution. Furthermore, we present numerical simulations illustrating the capability of acquiring a single time-resolved diffraction image based on the case-by-case studies of lattice dynamic behavior.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUXC06

About •

paper received ※ 14 May 2021 paper accepted ※ 28 July 2021 issue date ※ 31 August 2021

Export •

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

TUPAB223

Design of Double- and Multi-Bend Achromat Lattices with Large Dynamic Aperture and Approximate Invariants

1945

Y. Li, R.S. Rainer, V.V. Smaluk
BNL, Upton, New York, USA
K. Hwang, C.E. Mitchell, R.D. Ryne
LBNL, Berkeley, California, USA

Funding: Funded by U.S. Department of Energy (DOE) under Contract No. DE-SC0012704 (BNL) and DE-AC02-05CH11231 (LBNL), U.S. DOE Early Career Research Program under the Office of High Energy Physics.
A numerical method to design nonlinear double- and multi-bend achromat (DBA and MBA) lattices with approximate invariants of motion is described. The search for such nonlinear lattices is motivated by Fermilab’s Integrable Optics Test Accelerator (IOTA), whose design is based on an integrable Hamiltonian system with two invariants of motion. While it may not be possible to design an achromatic lattice for a dedicated synchrotron light source storage ring with one or more exact invariants of motion, it is possible to tune the sextupoles and octupoles in existing DBA and MBA lattices to produce approximate invariants. In our procedure, the lattice is tuned while minimizing the turn-by-turn fluctuations of the Courant-Snyder actions Jx and Jy at several distinct amplitudes, while simultaneously minimizing diffusion of the on-energy betatron tunes. The resulting lattices share some important features with integrable ones, such as a large dynamic aperture, trajectories confined to invariant tori, robustness to resonances and errors, and a large amplitude-dependent tune-spread.

Poster TUPAB223 [2.392 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB223

About •

paper received ※ 10 May 2021 paper accepted ※ 15 June 2021 issue date ※ 20 August 2021

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

TUPAB227

Simultaneous Compensation of Phase and Amplitude Dependent Geometrical Resonances Using Octupoles

1960

F. Plassard, Y. Hidaka, Y. Li, T.V. Shaftan, V.V. Smaluk, G.M. Wang
BNL, Upton, New York, USA

As the new generation of light sources are pushing toward diffraction limited storage rings with ultra-low emittance beams, nonlinear beam dynamics become increasingly difficult to control. It is a common practice for modern designs to use a sextupole scheme that allows simultaneous correction of natural chromaticity and energy independent, or geometrical, sextupolar resonances. However, the remaining higher order terms arising from the cross talks of the sextupole families set a strong limitation on the achievable dynamic aperture. This paper presents a simulation-based recipe to use octupoles together with this sextupole scheme to provide simultaneous self-compensation of linear amplitude dependent tune shift together with phase-dependent octupolar and higher order geometrical resonant driving terms. The correction method was built based on observations made on a simple FODO model, then applied to a realistic low emittance lattice, designed in the framework of the upgrade of the National Synchrotron Light Source II (NSLS-II).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB227

About •

paper received ※ 19 May 2021 paper accepted ※ 23 June 2021 issue date ※ 14 August 2021

Export •

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

WEPAB005

Design Status Update of the Electron-Ion Collider

2585

C. Montag, E.C. Aschenauer, G. Bassi, J. Beebe-Wang, J.S. Berg, M. Blaskiewicz, A. Blednykh, J.M. Brennan, S.J. Brooks, K.A. Brown, Z.A. Conway, K.A. Drees, A.V. Fedotov, W. Fischer, C. Folz, D.M. Gassner, X. Gu, R.C. Gupta, Y. Hao, A. Hershcovitch, C. Hetzel, D. Holmes, H. Huang, W.A. Jackson, J. Kewisch, Y. Li, C. Liu, H. Lovelace III, Y. Luo, M. Mapes, D. Marx, G.T. McIntyre, F. Méot, M.G. Minty, S.K. Nayak, R.B. Palmer, B. Parker, S. Peggs, B. Podobedov, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, S. Seletskiy, V.V. Smaluk, K.S. Smith, S. Tepikian, R. Than, P. Thieberger, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, S. Verdú-Andrés, E. Wang, D. Weiss, F.J. Willeke, H. Witte, Q. Wu, W. Xu, A. Zaltsman, W. Zhang
BNL, Upton, New York, USA
S.V. Benson, J.M. Grames, F. Lin, T.J. Michalski, V.S. Morozov, E.A. Nissen, J.P. Preble, R.A. Rimmer, T. Satogata, A. Seryi, M. Wiseman, W. Wittmer, Y. Zhang
JLab, Newport News, Virginia, USA
Y. Cai, Y.M. Nosochkov, G. Stupakov, M.K. Sullivan
SLAC, Menlo Park, California, USA
K.E. Deitrick, C.M. Gulliford, G.H. Hoffstaetter, J.E. Unger
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA
T. Satogata
ODU, Norfolk, Virginia, USA
D. Xu
FRIB, East Lansing, Michigan, USA

Funding: Work supported by BSA, LLC under Contract No. DE-SC0012704, by JSA, LLC under Contract No. DE-AC05-06OR23177, and by SLAC under Contract No. DE-AC02-76SF00515 with the U.S. Department of Energy.
The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community in the White Paper. Over the past year activities have been focused on maturing the design, and on developing alternatives to mitigate risk. These include improvements of the interaction region design as well as modifications of the hadron ring vacuum system to accommodate the high average and peak beam currents. Beam dynamics studies have been performed to determine and optimize the dynamic aperture in the two collider rings and the beam-beam performance. We will present the EIC design with a focus on recent developments.

Poster WEPAB005 [2.095 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB005

About •

paper received ※ 14 May 2021 paper accepted ※ 22 June 2021 issue date ※ 16 August 2021

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WEPAB239

Effect of Chromaticity and Feedback on Transverse Head-Tail Instability

3189

V.V. Smaluk, G. Bassi, A. Blednykh, A. Khan
BNL, Upton, New York, USA

Funding: This work was supported by the US Department of Energy under contract DE-SC0012704.
The head-tail instability caused by the beam interaction with short-range wakefields is a major limitation for the single-bunch beam intensity in circular accelerators. The combined effect of the transverse feedback systems and chromaticity suppressing the instability is discussed. Theoretical and experimental studies of the head-tail instability and methods of its mitigation are reviewed. Results of experimental studies of the transverse mode coupling carried out at NSLS-II are compared with the theoretical model and numerical simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB239

About •

paper received ※ 19 May 2021 paper accepted ※ 24 June 2021 issue date ※ 12 August 2021

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

THPAB240

Combined Effect of IBS and Impedance on the Longitudinal Beam Dynamics

4274

A. Blednykh
Brookhaven National Laboratory (BNL), Electron-Ion Collider, Upton, New York, USA
B. Bacha, G. Bassi, T.V. Shaftan, V.V. Smaluk
BNL, Upton, New York, USA
M. Borland, R.R. Lindberg
ANL, Lemont, Illinois, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The horizontal/vertical emittances, the bunch length, and the energy spread increase have been studied in the NSLS-II as a function of a single bunch current. The monotonic growth of the horizontal emittance dependence and the energy spread dependence on the single bunch current below the microwave instability threshold can be explained by the Intrabeam Scattering Effect (IBS). The IBS effect results in an increase in the bunch length and the microwave instability thresholds. It was observed experimentally by varying the vertical emittance. To compare with experimental data, particle tracking simulations have been performed with the ELEGANT code including both IBS and the total longitudinal wakefield calculated from the 3D electromagnetic code GdfidL. The same particle tracking simulations have also been applied for the APS-U project, where IBS is predicted to produce only a marginal effect.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB240

About •

paper received ※ 20 May 2021 paper accepted ※ 05 July 2021 issue date ※ 14 August 2021

Export •

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