IPAC2016 - Classification: 05 Beam Dynamics and Electromagnetic Fields / D09 Emittance Manipulation, Bunch Compression and Cooling

Paper	Title	Page
WEPOY001	First Field Integral Measurement Campaign for Air Coil	2991
	Z. Zhao, B. Du, Q.K. Jia USTC/NSRL, Hefei, Anhui, People's Republic of China S. Karabekyan, J. Pflüger, M. Yakopov XFEL. EU, Hamburg, Germany
	For the operation of the air coils, which are needed for the undulator segments of the European x-ray free-electron laser (E-XFEL), precise conversion constants are needed to properly convert excitation current to steering strength. This paper describes the measurement of all 200 air coils, needed for this purpose using the short moving wire (MW) system. A LabView program was developed to measure the distribution of first field integral of both vertical (B_y) and horizontal (B_z) magnetic field components in the median plane of an air coil automatically. The program is an adaptation of the existing program, which was used to characterize magnetic properties of the phase shifters (PS). Before doing the measurements the new program automatically finds the centers of B_y and B_z components, which are found to match with the geometrical centers with sufficient accuracy. After the measuring procedure is complete, the results are presented as graphics output and final tables. It shows that the measurement results can fully meet the design requirements of E-XFEL. For all measurements the excitation current of the coils was set to 1 Ampere.
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WEPOY009	Simulation Study of Emittance Growth from Coulomb Explosion in a Charge Separator System After Stripping	3005
	M. Droba, O. Meusel, U. Ratzinger IAP, Frankfurt am Main, Germany
	Funding: BMBF-05P15RFRBA A computer 3D particle-in-cell (PIC) simulation is used to examine the emittance growth of an intense heavy ion beam after a charge stripper. Multi-species dynamics of the bunched uranium beam with various charge states and including compensation electrons will be presented. The rms-emittance growth shows different behaviour in the horizontal, vertical and longitudinal planes, dependent on initial conditions, like a bunch size, beam current and phase space ellipse orientation. An optimization of initial parameters is therefore crucial for a successful and efficient post-acceleration. The role of the separation system and of co-moving electrons will be discussed for the example of the GSI-Unilac.
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WEPOY010	Bunch Compression at the Recirculation Loop of the Compact ERL	3008
	M. Shimada, K. Harada, Y. Honda, T. Miyajima, N. Nakamura, T. Obina, R. Takai, A. Ueda KEK, Ibaraki, Japan
	The compact Energy Recovery Linac (cERL) has been operated as a test facility for the future light-source since 2013. One of the targets of the beam commissioning of this winter is demonstration of bunch compression. The bunch has energy chirp in longitudinal direction by off crest acceleration and the bunch length is compressed in non-isochronous arc section. The short electron bunch is spread in the return arc to suppress the energy spread at the main beam dump. Four sextupole magnets were installed in two arcs in November 2015 to correct the squared term induced by RF curvature. The best position was determined by the beam tracking by elegant including Coherent Synchrotron Radiation (CSR) wake. The bunch length is measured by OTR in the south straight section just after the first arc. We present the demonstration of the bunch compression in this report.
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WEPOY015	Longitudinal Bram Dynamics at Rf-Compressor	3011
SUPSS059	use link to see paper's listing under its alternate paper code
	A.V. Andrianov BINP SB RAS, Novosibirsk, Russia
	Nowadays the usage of charged particle beams for study of nature became widespread. Modern experiments are require particle beams with duration around hundreds femtosecond. Relatively simple and cheap method of production such pulses is using RF-gun with photocathode and then the special insertion device which compress the beam. The paper described the RF-compressor for the electron beam. In result of work was obtained a device configuration. Electromagnetic field configuration and distribution were simulated for the configuration. Beam dynamics was computed in this field distribution. Incoming beam parameters are following: beam length is 1-5ps, beam charge is 0.1-2pC and energy is 3MeV. Output beam duration was compressed to less than 150fs. Influence of RF-compressor at beam parameters was estimated.
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WEPOY016	Use of Nonuniform Magnets for Emittance Reduction	3014
	E.B. Levichev, G.N. Baranov, S.V. Sinyatkin BINP SB RAS, Novosibirsk, Russia
	We study a theoretical minimum emittance (TME) for a non-uniform bending magnet including a three-step bend (sandwich magnet), a dipole with linear ramp of the bend-ing radius and the same but with a central segment of constant field. We derive expression for the minimum emittance and expand it into a power series with respect to the bending angle. A zero-order term naturally gives the uniform magnet TME while higher-order terms are responsible for the emittance reduction. Theoretical re-sults are verified by numerical simulation.
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WEPOY018	Study on Electron Beam Transverse Emittance at the Linac-based THz Laboratory in Thailand	3017
SUPSS060	use link to see paper's listing under its alternate paper code
	K. Kosaentor IST, Chiang Mai, Thailand S. Rimjaem Chiang Mai University, Chiang Mai, Thailand
	This research focuses on simulation of transverse emittance of electron beams, which are produced from a thermionic RF-gun at the Plasma and Beam Physics (PBP) Research Facility, Chiang Mai University (CMU). The RF-gun is used to together with an alpha magnet for serving as the electron injector system for the PBP linac-based THz source. The quadrupole scan technique is utilized to measure the transverse beam emittance at the entrance of the alpha magnet. The experimental setup consists of quadrupole magnets with a maximum gradient of 7.01 T/m, a drift tube, and a movable fluorescent screen station. Beam dynamic simulations by using the computer codes PARMELA and ELEGANTare performed to track electrons from the cathode to the experimental station. In this contribution, the emittance values from simulations including the space charge effects will be reported. This work has been supported by the CMU Junior Research Fellowship Program, Department of Physics and Material Science, Faculty of science, Chiang Mai University.
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WEPOY019	Beam Optimization Study for an X-ray FEL Oscillator at the LCLS-II	3020
	W. Qin, S. Huang, K.X. Liu PKU, Beijing, People's Republic of China K.L.F. Bane, Y. Ding, Z. Huang, T.J. Maxwell SLAC, Menlo Park, California, USA K.-J. Kim, R.R. Lindberg ANL, Argonne, Ilinois, USA
	The 4 GeV LCLS-II superconducting linac with high repetition beam rate enables the possibility to drive an X-Ray FEL oscillator at harmonic frequencies . Compared to the regular LCLS-II machine setup, the oscillator mode requires a much longer bunch length with a relatively lower current. Also a flat longitudinal phase space distribution is critical to maintain the FEL gain since the X-ray cavity has extremely narrow bandwidth. In this paper, we study the longitudinal phase space optimization including shaping the initial beam from the injector and optimizing the bunch compressor and dechirper parameters. We obtain a bunch with a flat energy chirp over 400 fs in the core part with current above 100 A. The optimization was based on LiTrack and Elegant simulations using LCLS-II beam parameters. T. J. Maxwell et al., Feasibility study for an X-ray FEL oscillator at the LCLS-II, IPAC15, TUPMA028.
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WEPOY021	Nonlinear Phase Distortion in a Ti:Sapphire Optical Amplifier for Optical Stochastic Cooling	3024
	M.B. Andorf, P. Piot Northern Illinois University, DeKalb, Illinois, USA V.A. Lebedev, P. Piot, J. Ruan Fermilab, Batavia, Illinois, USA
	Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359. Optical Stochastic Cooling (OSC) has been considered for future high-luminosity colliders as it offers much faster cooling time in comparison to the micro-wave stochastic cooling. The OSC technique relies on collecting and amplifying a broadband optical signal from a pickup undulator and feeding the amplified signal back to the beam. It creates a corrective kick in a kicker undulator. Owing to its superb gain qualities and broadband amplification features, Titanium:Sapphire medium has been considered as a gain medium for the optical amplifier (OA) needed in the OSC. A limiting factor for any OA used in OSC is the possibility of nonlinear phase distortions. In this paper we experimentally measure phase distortions by inserting a single-pass OA into one leg of a Mach-Zehnder interferometer. The measurement results are used to estimate the reduction of the corrective kick a particle would receive due to these phase distortions in the kicker undulator. A. Zholents, and M. Zolotorev. Proc. PAC'97, 1805 (1998).
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WEPOY022	Light Optics for Optical Stochastic Cooling	3028
SUPSS058	use link to see paper's listing under its alternate paper code
	M.B. Andorf, P. Piot Northern Illinois University, DeKalb, Illinois, USA V.A. Lebedev, P. Piot, J. Ruan Fermilab, Batavia, Illinois, USA
	Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359. In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material. V. Lebedev, et al., Proc. COOL'15 (in press, 2015).
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WEPOY023	Beam Dynamics Studies for Coherent Electron Cooling Experiment	3032
	Y.H. Wu, D. Kayran, V. Litvinenko, I. Pinayev BNL, Upton, Long Island, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Coherent electron Cooling (CeC)* is a proposed advanced beam cooling method that has the potential to reduce the ion beam emittance in significantly shorter time compared to existing cooling methods. The newly constructed linear electron accelerator for the CeC experiment can generate electron beams with the required beam parameters for effective cooling. In this paper, we show simulation studies for the CEC linac by using the PARMELA and ELEGANT* beam dynamics tracking codes. * V.N.Litvinenko and Y.S.Derbenev, PRL 102, 114801 (2009) Lloyd M.Young, Parmela manual, Los Alamos National Laboratory * M. Borland, Elegant, Argonne National Laboratory (2000)
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Paper

Title

Page

First Field Integral Measurement Campaign for Air Coil

2991

Z. Zhao, B. Du, Q.K. Jia
USTC/NSRL, Hefei, Anhui, People's Republic of China
S. Karabekyan, J. Pflüger, M. Yakopov
XFEL. EU, Hamburg, Germany

For the operation of the air coils, which are needed for the undulator segments of the European x-ray free-electron laser (E-XFEL), precise conversion constants are needed to properly convert excitation current to steering strength. This paper describes the measurement of all 200 air coils, needed for this purpose using the short moving wire (MW) system. A LabView program was developed to measure the distribution of first field integral of both vertical (B_y) and horizontal (B_z) magnetic field components in the median plane of an air coil automatically. The program is an adaptation of the existing program, which was used to characterize magnetic properties of the phase shifters (PS). Before doing the measurements the new program automatically finds the centers of B_y and B_z components, which are found to match with the geometrical centers with sufficient accuracy. After the measuring procedure is complete, the results are presented as graphics output and final tables. It shows that the measurement results can fully meet the design requirements of E-XFEL. For all measurements the excitation current of the coils was set to 1 Ampere.

Export •

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WEPOY009

Simulation Study of Emittance Growth from Coulomb Explosion in a Charge Separator System After Stripping

3005

M. Droba, O. Meusel, U. Ratzinger
IAP, Frankfurt am Main, Germany

Funding: BMBF-05P15RFRBA
A computer 3D particle-in-cell (PIC) simulation is used to examine the emittance growth of an intense heavy ion beam after a charge stripper. Multi-species dynamics of the bunched uranium beam with various charge states and including compensation electrons will be presented. The rms-emittance growth shows different behaviour in the horizontal, vertical and longitudinal planes, dependent on initial conditions, like a bunch size, beam current and phase space ellipse orientation. An optimization of initial parameters is therefore crucial for a successful and efficient post-acceleration. The role of the separation system and of co-moving electrons will be discussed for the example of the GSI-Unilac.

Export •

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WEPOY010

Bunch Compression at the Recirculation Loop of the Compact ERL

3008

M. Shimada, K. Harada, Y. Honda, T. Miyajima, N. Nakamura, T. Obina, R. Takai, A. Ueda
KEK, Ibaraki, Japan

The compact Energy Recovery Linac (cERL) has been operated as a test facility for the future light-source since 2013. One of the targets of the beam commissioning of this winter is demonstration of bunch compression. The bunch has energy chirp in longitudinal direction by off crest acceleration and the bunch length is compressed in non-isochronous arc section. The short electron bunch is spread in the return arc to suppress the energy spread at the main beam dump. Four sextupole magnets were installed in two arcs in November 2015 to correct the squared term induced by RF curvature. The best position was determined by the beam tracking by elegant including Coherent Synchrotron Radiation (CSR) wake. The bunch length is measured by OTR in the south straight section just after the first arc. We present the demonstration of the bunch compression in this report.

Export •

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

WEPOY015

Longitudinal Bram Dynamics at Rf-Compressor

3011

SUPSS059

use link to see paper's listing under its alternate paper code

A.V. Andrianov
BINP SB RAS, Novosibirsk, Russia

Nowadays the usage of charged particle beams for study of nature became widespread. Modern experiments are require particle beams with duration around hundreds femtosecond. Relatively simple and cheap method of production such pulses is using RF-gun with photocathode and then the special insertion device which compress the beam. The paper described the RF-compressor for the electron beam. In result of work was obtained a device configuration. Electromagnetic field configuration and distribution were simulated for the configuration. Beam dynamics was computed in this field distribution. Incoming beam parameters are following: beam length is 1-5ps, beam charge is 0.1-2pC and energy is 3MeV. Output beam duration was compressed to less than 150fs. Influence of RF-compressor at beam parameters was estimated.

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

WEPOY016

Use of Nonuniform Magnets for Emittance Reduction

3014

E.B. Levichev, G.N. Baranov, S.V. Sinyatkin
BINP SB RAS, Novosibirsk, Russia

We study a theoretical minimum emittance (TME) for a non-uniform bending magnet including a three-step bend (sandwich magnet), a dipole with linear ramp of the bend-ing radius and the same but with a central segment of constant field. We derive expression for the minimum emittance and expand it into a power series with respect to the bending angle. A zero-order term naturally gives the uniform magnet TME while higher-order terms are responsible for the emittance reduction. Theoretical re-sults are verified by numerical simulation.

Export •

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

WEPOY018

Study on Electron Beam Transverse Emittance at the Linac-based THz Laboratory in Thailand

3017

SUPSS060

use link to see paper's listing under its alternate paper code

K. Kosaentor
IST, Chiang Mai, Thailand
S. Rimjaem
Chiang Mai University, Chiang Mai, Thailand

This research focuses on simulation of transverse emittance of electron beams, which are produced from a thermionic RF-gun at the Plasma and Beam Physics (PBP) Research Facility, Chiang Mai University (CMU). The RF-gun is used to together with an alpha magnet for serving as the electron injector system for the PBP linac-based THz source. The quadrupole scan technique is utilized to measure the transverse beam emittance at the entrance of the alpha magnet. The experimental setup consists of quadrupole magnets with a maximum gradient of 7.01 T/m, a drift tube, and a movable fluorescent screen station. Beam dynamic simulations by using the computer codes PARMELA and ELEGANTare performed to track electrons from the cathode to the experimental station. In this contribution, the emittance values from simulations including the space charge effects will be reported.
This work has been supported by the CMU Junior Research Fellowship Program, Department of Physics and Material Science, Faculty of science, Chiang Mai University.

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WEPOY019

Beam Optimization Study for an X-ray FEL Oscillator at the LCLS-II

3020

W. Qin, S. Huang, K.X. Liu
PKU, Beijing, People's Republic of China
K.L.F. Bane, Y. Ding, Z. Huang, T.J. Maxwell
SLAC, Menlo Park, California, USA
K.-J. Kim, R.R. Lindberg
ANL, Argonne, Ilinois, USA

The 4 GeV LCLS-II superconducting linac with high repetition beam rate enables the possibility to drive an X-Ray FEL oscillator at harmonic frequencies *. Compared to the regular LCLS-II machine setup, the oscillator mode requires a much longer bunch length with a relatively lower current. Also a flat longitudinal phase space distribution is critical to maintain the FEL gain since the X-ray cavity has extremely narrow bandwidth. In this paper, we study the longitudinal phase space optimization including shaping the initial beam from the injector and optimizing the bunch compressor and dechirper parameters. We obtain a bunch with a flat energy chirp over 400 fs in the core part with current above 100 A. The optimization was based on LiTrack and Elegant simulations using LCLS-II beam parameters.
* T. J. Maxwell et al., Feasibility study for an X-ray FEL oscillator at the LCLS-II, IPAC15, TUPMA028.

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WEPOY021

Nonlinear Phase Distortion in a Ti:Sapphire Optical Amplifier for Optical Stochastic Cooling

3024

M.B. Andorf, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
V.A. Lebedev, P. Piot, J. Ruan
Fermilab, Batavia, Illinois, USA

Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359.
Optical Stochastic Cooling (OSC) has been considered for future high-luminosity colliders as it offers much faster cooling time in comparison to the micro-wave stochastic cooling. The OSC technique relies on collecting and amplifying a broadband optical signal from a pickup undulator and feeding the amplified signal back to the beam. It creates a corrective kick in a kicker undulator. Owing to its superb gain qualities and broadband amplification features, Titanium:Sapphire medium has been considered as a gain medium for the optical amplifier (OA) needed in the OSC*. A limiting factor for any OA used in OSC is the possibility of nonlinear phase distortions. In this paper we experimentally measure phase distortions by inserting a single-pass OA into one leg of a Mach-Zehnder interferometer. The measurement results are used to estimate the reduction of the corrective kick a particle would receive due to these phase distortions in the kicker undulator.
* A. Zholents, and M. Zolotorev. Proc. PAC'97, 1805 (1998).

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WEPOY022

Light Optics for Optical Stochastic Cooling

3028

SUPSS058

use link to see paper's listing under its alternate paper code

M.B. Andorf, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
V.A. Lebedev, P. Piot, J. Ruan
Fermilab, Batavia, Illinois, USA

Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359.
In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction*. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material.
* V. Lebedev, et al., Proc. COOL'15 (in press, 2015).

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WEPOY023

Beam Dynamics Studies for Coherent Electron Cooling Experiment

3032

Y.H. Wu, D. Kayran, V. Litvinenko, I. Pinayev
BNL, Upton, Long Island, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Coherent electron Cooling (CeC)* is a proposed advanced beam cooling method that has the potential to reduce the ion beam emittance in significantly shorter time compared to existing cooling methods. The newly constructed linear electron accelerator for the CeC experiment can generate electron beams with the required beam parameters for effective cooling. In this paper, we show simulation studies for the CEC linac by using the PARMELA** and ELEGANT*** beam dynamics tracking codes.
* V.N.Litvinenko and Y.S.Derbenev, PRL 102, 114801 (2009)
** Lloyd M.Young, Parmela manual, Los Alamos National Laboratory
*** M. Borland, Elegant, Argonne National Laboratory (2000)

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