IPAC2016 - List of Keywords (collective-effects)

Paper	Title	Other Keywords	Page
TUPMY031	Estimation and Suppression of Aberrations in Emittance Exchange based Current Profile Shaping	emittance, space-charge, acceleration, FEL	1615
	G. Ha, M.-H. Cho, W. Namkung POSTECH, Pohang, Kyungbuk, Republic of Korea W. Gai, G. Ha, K.-J. Kim, J.G. Power ANL, Argonne, Illinois, USA
	The longitudinal current profile manipulation has been explored for many applications including THz radiation, FEL and advanced acceleration schemes. Especially, collinear dielectric wakefield accelerations require a microbunch shaping for a high transformer ratio. We have studied aberrations from the emittance exchange based current profile shaping to preserve the high transformer ratio. All second order aberration terms in the double dog-leg emittance exchange beam line are discovered. Aberration patterns from each aberration sources like second order terms, space-charge, and CSR and their effect on the transformer ratio are estimated analytically. These aberration sources and corresponding patterns are confirmed using a particle tracking code GPT. Simple methods to suppress each aberration will be presented too. All calculation in this work is done with a double dog-leg emittance exchange beam line.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY031
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TUPOR005	A Parallelized Vlasov-Fokker-Planck-Solver for Desktop PCs	simulation, damping, synchrotron, bunching	1658
	P. Schönfeldt, M. Brosi, A.-S. Müller, J.L. Steinmann KIT, Karlsruhe, Germany
	In order simulate the dynamics of an electron bunch due to the self-interaction with its own coherent synchrotron radiation it is a well established method to numerically solve the Vlasov-Fokker-Planck equation. In this paper we present a new, modularly extensible program that uses OpenCL to massively parallelize the computation, allowing a standard desktop PC to work with appropriate accuracy and yield reliable results within minutes. We provide numerical stability studies of over a huge parameter range and comparisons of our numerical results to other techniques.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR005
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TUPOR020	Combination of Density and Energy Modulation in Microbunching Analysis	electron, synchrotron-radiation, radiation, synchrotron	1703
	C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA R. Li JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Microbunching instability (MBI) has been one of the most challenging issues in the transport of high-brightness electron beams for modern recirculating or energy recovery linac machines. Recently we have developed and implemented a Vlasov solver* to calculate microbunching gain for an arbitrary beamline lattice design, based on the extension of early theoretical formulation for the microbunching amplification from an initial density perturbation to the final density modulation. For more thorough analyses, in addition to the case of (initial) density to (final) density amplification, we in this paper extend the previous formulation to more general cases, including energy-to-density, density-to-energy and energy-to-energy amplifications for a recirculation machine. Such semi-analytical formulae are then incorporated into our Vlasov solver, and reasonable agreement is obtained when the semi-analytical results are benchmarked with particle tracking simulation using ELEGANT. C.Y. Tsai et al, FEL'15 S. Heifets et al, PRSTAB 5, 064401 (2002), Z. Huang and K. Kim, PRSTAB 5, 074401 (2002), M. Vneturini, PRSTAB 10, 104401 (2007) * M. Borland, APS LS-287, 2000
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR020
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WEOBB01	Single Micron Single-Bunch Turn-by-Turn BPM Resolution Achieved at NSLS-II	experiment, storage-ring, operation, Windows	2095
	B. Podobedov, W.X. Cheng, K. Ha, Y. Hidaka, J. Mead, O. Singh, K. Vetter BNL, Upton, Long Island, New York, USA
	NSLS-II state-of-the-art BPMs provide a single micron turn-by-turn BPM resolution for any bunch train of reasonable intensity. For certain beam dynamics studies a similar, or even better, resolution is desired for a single-, or a few-bunch fill, which is not yet available with our standard BPM signal processing. This paper describes our experience with more advanced BPM ADC signal processing which allowed us to significantly improve turn-by-turn BPM resolution in single bunch mode down to the level of about one micron at ~1 nC/bunch. We also present the examples of machine studies that benefit from this BPM performance enhancement.
	Slides WEOBB01 [2.565 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOBB01
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WEPOW057	Spectral Analysis of Turn-by-Turn Data	simulation, betatron, storage-ring, Windows	2979
	J. Choi BNL, Upton, Long Island, New York, USA
	Funding: DOE contract No: DE-SC0012704 With the recent technical developments, it is now popular to get the turn-by-turn data for the storage ring. Even though response matrix based analysis, like LOCO, have strong advantages in lattice analysis, the turn-by-turn data analysis is quite attractive because it takes very short time in data acquisition and many effective analyzing methods have been developed. Basically, such analysis requires accurate estimation of peaks of frequency spectra with high resolution. In this paper, we review the various accuratenesses of such estimations depending on processes using exact sinusoidal data and apply the end-matching method to simulation and measurement.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW057
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Paper

Title

Other Keywords

Page

TUPMY031

Estimation and Suppression of Aberrations in Emittance Exchange based Current Profile Shaping

emittance, space-charge, acceleration, FEL

1615

G. Ha, M.-H. Cho, W. Namkung
POSTECH, Pohang, Kyungbuk, Republic of Korea
W. Gai, G. Ha, K.-J. Kim, J.G. Power
ANL, Argonne, Illinois, USA

The longitudinal current profile manipulation has been explored for many applications including THz radiation, FEL and advanced acceleration schemes. Especially, collinear dielectric wakefield accelerations require a microbunch shaping for a high transformer ratio. We have studied aberrations from the emittance exchange based current profile shaping to preserve the high transformer ratio. All second order aberration terms in the double dog-leg emittance exchange beam line are discovered. Aberration patterns from each aberration sources like second order terms, space-charge, and CSR and their effect on the transformer ratio are estimated analytically. These aberration sources and corresponding patterns are confirmed using a particle tracking code GPT. Simple methods to suppress each aberration will be presented too. All calculation in this work is done with a double dog-leg emittance exchange beam line.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY031

Export •

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

TUPOR005

A Parallelized Vlasov-Fokker-Planck-Solver for Desktop PCs

simulation, damping, synchrotron, bunching

1658

P. Schönfeldt, M. Brosi, A.-S. Müller, J.L. Steinmann
KIT, Karlsruhe, Germany

In order simulate the dynamics of an electron bunch due to the self-interaction with its own coherent synchrotron radiation it is a well established method to numerically solve the Vlasov-Fokker-Planck equation. In this paper we present a new, modularly extensible program that uses OpenCL to massively parallelize the computation, allowing a standard desktop PC to work with appropriate accuracy and yield reliable results within minutes. We provide numerical stability studies of over a huge parameter range and comparisons of our numerical results to other techniques.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR005

Export •

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

TUPOR020

Combination of Density and Energy Modulation in Microbunching Analysis

electron, synchrotron-radiation, radiation, synchrotron

1703

C.-Y. Tsai
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
R. Li
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Microbunching instability (MBI) has been one of the most challenging issues in the transport of high-brightness electron beams for modern recirculating or energy recovery linac machines. Recently we have developed and implemented a Vlasov solver* to calculate microbunching gain for an arbitrary beamline lattice design, based on the extension of early theoretical formulation** for the microbunching amplification from an initial density perturbation to the final density modulation. For more thorough analyses, in addition to the case of (initial) density to (final) density amplification, we in this paper extend the previous formulation to more general cases, including energy-to-density, density-to-energy and energy-to-energy amplifications for a recirculation machine. Such semi-analytical formulae are then incorporated into our Vlasov solver, and reasonable agreement is obtained when the semi-analytical results are benchmarked with particle tracking simulation using ELEGANT***.
* C.Y. Tsai et al, FEL'15
** S. Heifets et al, PRSTAB 5, 064401 (2002), Z. Huang and K. Kim, PRSTAB 5, 074401 (2002), M. Vneturini, PRSTAB 10, 104401 (2007)
*** M. Borland, APS LS-287, 2000

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR020

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WEOBB01

Single Micron Single-Bunch Turn-by-Turn BPM Resolution Achieved at NSLS-II

experiment, storage-ring, operation, Windows

2095

B. Podobedov, W.X. Cheng, K. Ha, Y. Hidaka, J. Mead, O. Singh, K. Vetter
BNL, Upton, Long Island, New York, USA

NSLS-II state-of-the-art BPMs provide a single micron turn-by-turn BPM resolution for any bunch train of reasonable intensity. For certain beam dynamics studies a similar, or even better, resolution is desired for a single-, or a few-bunch fill, which is not yet available with our standard BPM signal processing. This paper describes our experience with more advanced BPM ADC signal processing which allowed us to significantly improve turn-by-turn BPM resolution in single bunch mode down to the level of about one micron at ~1 nC/bunch. We also present the examples of machine studies that benefit from this BPM performance enhancement.

Slides WEOBB01 [2.565 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOBB01

Export •

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

WEPOW057

Spectral Analysis of Turn-by-Turn Data

simulation, betatron, storage-ring, Windows

2979

J. Choi
BNL, Upton, Long Island, New York, USA

Funding: DOE contract No: DE-SC0012704
With the recent technical developments, it is now popular to get the turn-by-turn data for the storage ring. Even though response matrix based analysis, like LOCO, have strong advantages in lattice analysis, the turn-by-turn data analysis is quite attractive because it takes very short time in data acquisition and many effective analyzing methods have been developed. Basically, such analysis requires accurate estimation of peaks of frequency spectra with high resolution. In this paper, we review the various accuratenesses of such estimations depending on processes using exact sinusoidal data and apply the end-matching method to simulation and measurement.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW057

Export •

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