IPAC2017 - List of Authors (White, S.M.)

Paper	Title	Page
MOPIK063	Non-Linear Kickers Using Eddy Current Screens and Application to the ESRF	670
	S.M. White, M. Dubrulle, L. Farvacque, P. Henrissat, G. Le Bec, E. Plouviez, P. Raimondi, C. Richard ESRF, Grenoble, France
	The ESRF storage ring injection and accumulation is performed using standard 4-kickers bump and septum magnet. Sextupoles are located within the injection bump leading to significant bump non-closure during the ramp-up and ramp-down and optics distorsion for both stored and injected beam. Introducing non-linearities in the kickers allows for compensation of the perturbation from these sextupoles. We report on the feasibility of adding eddy current screens to a standard kicker magnet design to generate a non-linear field and its recent application to mitigate the injection perturbations at the ESRF.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK063
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TUPIK041	Cleaning of Parasitic Bunches for Time Structured Filling of the ESRF Storage Ring During Top Up Operation	1774
	E. Plouviez, L. Farvacque, J.M. Koch, T.P. Perron, B. Roche, K.B. Scheidt, R. Versteegen, S.M. White ESRF, Grenoble, France
	In order to generate time structured synchrotron radiation the 6GeV ESRF storage ring can be operated with 16 buckets filled with 15nC separated by 16 gaps of 61 nearly perfectly empty buckets. The contrast required by some users between the population of the main and empty buckets is 10¹¹. In order to obtain these empty buckets some RF knock out (cleaning) of the parasitic bunches is needed. Until now this cleaning was performed on the beam stored in the storage ring. Recently we have started to deliver this 16 bunches filling in a so called top up mode, drastically increasing the rate of the storage ring refills. In this top up mode it is very penalizing to perform the cleaning in the storage ring so we are now performing it in the booster synchrotron which accelerates the 200MeV beam coming from the linac up to 6GeV. We describe the set up used to perform the cleaning in the booster and all the measurement and experiments performed in order to correctly understand the origin of the unwanted electrons populating buckets of the gaps separating the 16 main bunches.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK041
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TUPVA045	Compensation of Head-on Beam-Beam Induced Resonance Driving Terms and Tune Spread in the Relativistic Heavy Ion Collider	2171
	W. Fischer, X. Gu, C. Liu, Y. Luo, A. Marusic, R.J. Michnoff, T.A. Miller, M.G. Minty, C. Montag, A.I. Pikin, G. Robert-Demolaize, V. Schoefer, P. Thieberger BNL, Upton, Long Island, New York, USA S.M. White ESRF, Grenoble, France
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The compensation consists of a lattice for the minimization of beam-beam driven resonance driving terms, and electron lenses for the reduction of the beam-beam induced tune spread. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA045
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WEPIK058	Preliminary Longitudinal Impedance Model for the ESRF-EBS	3063
	S.M. White ESRF, Grenoble, France
	In light sources, longitudinal beam coupling impedance can deteriorate performance through bunch lengthening or increased longitudinal emittance due to the microwave instability. Simulation estimates are therefore required to devise the appropriate counter-measures if necessary. The main contributors to the longitudinal impedance model of the new ESRF-EBS storage ring were simulated. A preliminary longitudinal impedance model is presented and preliminary tracking simulations are shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK058
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THPAB003	Harmonic RF System for the ESRF EBS	3684
	N. Carmignani, J. Jacob, B. Nash, S.M. White ESRF, Grenoble, France
	A harmonic RF system for bunch lengthening to increase the Touschek lifetime of the ESRF Extemely Brilliant Source (EBS) is under study. Multiparticle simulations have been performed to study the bunch lengthening and the bunch shape with impedance effect and with third or fourth harmonic cavities. The effect of a harmonic RF system on the microwave instability is studied, finding an increase in the threshold. The AC Robinson instability threshold with a superconducting harmonic cavity has been studied with multiparticle simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB003
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Paper

Title

Page

Non-Linear Kickers Using Eddy Current Screens and Application to the ESRF

670

S.M. White, M. Dubrulle, L. Farvacque, P. Henrissat, G. Le Bec, E. Plouviez, P. Raimondi, C. Richard
ESRF, Grenoble, France

The ESRF storage ring injection and accumulation is performed using standard 4-kickers bump and septum magnet. Sextupoles are located within the injection bump leading to significant bump non-closure during the ramp-up and ramp-down and optics distorsion for both stored and injected beam. Introducing non-linearities in the kickers allows for compensation of the perturbation from these sextupoles. We report on the feasibility of adding eddy current screens to a standard kicker magnet design to generate a non-linear field and its recent application to mitigate the injection perturbations at the ESRF.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK063

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

TUPIK041

Cleaning of Parasitic Bunches for Time Structured Filling of the ESRF Storage Ring During Top Up Operation

1774

E. Plouviez, L. Farvacque, J.M. Koch, T.P. Perron, B. Roche, K.B. Scheidt, R. Versteegen, S.M. White
ESRF, Grenoble, France

In order to generate time structured synchrotron radiation the 6GeV ESRF storage ring can be operated with 16 buckets filled with 15nC separated by 16 gaps of 61 nearly perfectly empty buckets. The contrast required by some users between the population of the main and empty buckets is 10¹¹. In order to obtain these empty buckets some RF knock out (cleaning) of the parasitic bunches is needed. Until now this cleaning was performed on the beam stored in the storage ring. Recently we have started to deliver this 16 bunches filling in a so called top up mode, drastically increasing the rate of the storage ring refills. In this top up mode it is very penalizing to perform the cleaning in the storage ring so we are now performing it in the booster synchrotron which accelerates the 200MeV beam coming from the linac up to 6GeV. We describe the set up used to perform the cleaning in the booster and all the measurement and experiments performed in order to correctly understand the origin of the unwanted electrons populating buckets of the gaps separating the 16 main bunches.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK041

Export •

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

TUPVA045

Compensation of Head-on Beam-Beam Induced Resonance Driving Terms and Tune Spread in the Relativistic Heavy Ion Collider

2171

W. Fischer, X. Gu, C. Liu, Y. Luo, A. Marusic, R.J. Michnoff, T.A. Miller, M.G. Minty, C. Montag, A.I. Pikin, G. Robert-Demolaize, V. Schoefer, P. Thieberger
BNL, Upton, Long Island, New York, USA
S.M. White
ESRF, Grenoble, France

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
A head-on beam-beam compensation scheme was implemented for operation in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The compensation consists of a lattice for the minimization of beam-beam driven resonance driving terms, and electron lenses for the reduction of the beam-beam induced tune spread. We describe the implementations of the lattice and electron lenses, and report on measurements of lattice properties and the effect of the electron lenses on the hadron beam.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA045

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WEPIK058

Preliminary Longitudinal Impedance Model for the ESRF-EBS

3063

S.M. White
ESRF, Grenoble, France

In light sources, longitudinal beam coupling impedance can deteriorate performance through bunch lengthening or increased longitudinal emittance due to the microwave instability. Simulation estimates are therefore required to devise the appropriate counter-measures if necessary. The main contributors to the longitudinal impedance model of the new ESRF-EBS storage ring were simulated. A preliminary longitudinal impedance model is presented and preliminary tracking simulations are shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK058

Export •

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

THPAB003

Harmonic RF System for the ESRF EBS

3684

N. Carmignani, J. Jacob, B. Nash, S.M. White
ESRF, Grenoble, France

A harmonic RF system for bunch lengthening to increase the Touschek lifetime of the ESRF Extemely Brilliant Source (EBS) is under study. Multiparticle simulations have been performed to study the bunch lengthening and the bunch shape with impedance effect and with third or fourth harmonic cavities. The effect of a harmonic RF system on the microwave instability is studied, finding an increase in the threshold. The AC Robinson instability threshold with a superconducting harmonic cavity has been studied with multiparticle simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB003

Export •

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