FLS2018 - List of Keywords (laser)

Paper	Title	Other Keywords	Page
TUA2WC01	Transportation and Manipulation of a Laser Plasma Acceleration Beam	ion, electron, undulator, plasma	56
	A. Ghaith, T. André, I.A. Andriyash, F. Blache, F. Bouvet, F. Briquez, M.-E. Couprie, Y. Dietrich, J.P. Duval, C. Herbeaux, N. Hubert, C.A. Kitegi, M. Labat, N. Leclercq, A. Lestrade, A. Loulergue, O. Marcouillé, F. Marteau, D. Oumbarek, P. Rommeluère, E. Roussel, M. Sebdaoui, K.T. Tavakoli, M. Valléau SOLEIL, Gif-sur-Yvette, France S. Bielawski, C. Evain, C. Szwaj PhLAM/CERLA, Villeneuve d'Ascq, France S. Corde, J. Gautier, G. Lambert, B. Mahieu, V. Malka, K.T. Phuoc, C. Thaury LOA, Palaiseau, France
	Funding: European Research Council advanced grant COXINEL - 340015 The ERC Advanced Grant COXINEL aims at demonstrating free electron laser amplification, at a resonant wavelength of 200 nm, based on a laser plasma acceleration source. To achieve the amplification, a 10 m long dedicated transport line was designed to manipulate the beam qualities. It starts with a triplet of permanent magnet with tunable gradient quadrupoles (QUAPEVA) that handles the highly divergent electron beam, a demixing chicane with a slit to reduce the energy spread per slice, and a set of electromagnetic quadrupoles to provide a chromatic focusing in a 2 m long cryogenic undulator. Electrons of energy 176 MeV were successfully transported throughout the line, where the beam positioning and dispersion were controlled efficiently thanks to a specific beam based alignment method, as well as the energy range by varying the slit width. Observations of undulator radiation for different undulator gaps are reported.
	Slides TUA2WC01 [2.465 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-TUA2WC01
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WEA1PL02	Dielectric Accelerators and Other Non-Plasma Accelerator Based Compact Light Sources	ion, undulator, electron, radiation	74
	R.J. England, Z. Huang SLAC, Menlo Park, California, USA
	Funding: U.S. Department of Energy DE-AC02-76SF00515; Gordon and Betty Moore Foundation GBMF4744 We review recent experimental progress in developing nanofabricated dielectric laser-driven accelerators and discuss the possibility of utilizing the unique sub-femtosecond electron pulse format these accelerators would provide to create ultra-compact EUV and X-ray radiation sources.
	Slides WEA1PL02 [16.828 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEA1PL02
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WEA1PL03	Attosecond Timing	ion, timing, FEL, electron	79
	F.X. Kärtner Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany K. Shafak CFEL, Hamburg, Germany K. Shafak Cycle GmbH, Hamburg, Germany M. Xin DESY, Hamburg, Germany
	Funding: This work was supported by DESY and the European Research Council under the European Union's Seventh Framework Program (FP/2007-2013) / ERC Grant Agreement No. 609920. Photon-science facilities such as X-ray free-electron lasers (XFELs) and intense-laser facilities are emerging world-wide with some of them producing sub-fs X-ray pulses. These facilities are in need of a high-precision timing distribution system, which can synchronize various microwave and optical sub-sources across multi-km distances with attosecond precision. Here, we report on a synchronous laser-microwave network that permits attosecond precision across km-scale distances. This was achieved by developing new ultrafast timing metrology devices and carefully balancing the fiber nonlinearities and fundamental noise contributions in the system. New polarization-noise-suppressed balanced optical crosscorrelators and free-space-coupled balanced optical-microwave phase detectors for improved noise performance have been implemented. Residual second- and third-order dispersion in the fiber links are carefully compensated with additional dispersion-compensating fiber to suppress link-induced Gordon-Haus jitter and to minimize output pulse duration; the link power is stabilized to minimize the nonlinearity-induced jitter as well as to maximize the signal to noise ratio for locking.
	Slides WEA1PL03 [5.888 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEA1PL03
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WEA2WD01	QUAPEVA: Variable High Gradient Permanent Magnet Quadrupole	ion, quadrupole, electron, multipole	89
	C.A. Kitegi, T. André, M.-E. Couprie, A. Ghaith, J. Idam, A. Loulergue, F. Marteau, D. Oumbarek, M. Sebdaoui, M. Valléau, J. Vétéran SOLEIL, Gif-sur-Yvette, France C. Benabderrahmane, J. Chavanne, G. Le Bec ESRF, Grenoble, France O. Cosson, F. Forest, P. Jivkov, J.L. Lancelot Sigmaphi, Vannes, France P. N'gotta MAX IV Laboratory, Lund University, Lund, Sweden C. Vallerand LAL, Orsay, France
	We present the magnetic and the mechanical design of tunable high gradient permanent magnet (PM) quadrupoles. The tunable gradient of the so-called QUAPEVAS extends from 100T/m up to 200T/m. Seven of them with various lengths, ranging from 26mm up to 100mm, for different integrated quadrupole strengths were manufactured. The measured magnetic performance of these devices is also reported. These devices were successfully developed to transport laser plasma accelerated electron beam. Such applications have however less stringent multipole harmonic content constraints than diffraction limited Light sources. Trails for lowering the multipole harmonics will be discussed.
	Slides WEA2WD01 [3.093 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEA2WD01
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WEP2PT008	Microbunching Instability Study in the Linac-Driven FERMI FEL Spreader Beam Line	ion, linac, FEL, electron	108
	S. Di Mitri, S. Spampinati Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Suppression of microbunching instability (MBI) along high brightness electron beam delivery systems is a priority for Free Electron lasers (FELs) aiming at very narrow bandwidth. The impact of MBI on FEL spectral brilliance is aggravated by the growing demand for multi-user FEL facilities, which adopt multi-bend switchyard lines traversed by high charge density electron beams. This study provides practical guidelines to switchyards design largely immune to MBI, by focusing on the FERMI FEL Spreader line. First, two MBI analytical models [1, 2] are successfully benchmarked along the accelerator. Being the second model flexible enough to describe an arbitrary multi-bend line, and found it in agreement with particle tracking and experimental results, it was used to demonstrate that a newly proposed Spreader optics provides unitary MBI gain while preserving the electron beam brightness. [1] Z. Huang and K.-J. Kim, Phys. Rev. Special Topics - Accel. Beams 5, 074401 (2002) [2] R.A. Bosch, K.J. Kleman, and J. Wu, Phys. Rev. Special Topics - Accel. Beams 11, 090702 (2008)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT008
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WEP2PT034	Beyond Uniform Ellipsoidal Laser Shaping for Beam Brightness Improvements at PITZ	ion, emittance, flattop, simulation	146
	H.J. Qian, J.D. Good, C. Koschitzki, M. Krasilnikov, F. Stephan DESY Zeuthen, Zeuthen, Germany
	In the last decades, photoinjector brightness has improved significantly, driven by the needs of free electron lasers and many other applications. One of the key elements is photocathode laser shaping for reducing emittance growth from nonlinear space charge forces. At the photoinjector test facility at DESY in Zeuthen (PITZ), a uniform flattop laser was used to achieve record low emittance for a bunch charge from 20 pC to 1 nC. Due to the ideal 3D space charge force linearization in ellipsoidal electron bunches, uniform ellipsoidal photocathode laser shaping were proposed to improve beam emittance up to 33% for 1 nC beam at PITZ. In this paper, we will show even further transverse emittance improvements in simulations for both flattop and ellipsoidal laser pulses with parabolic radial distribution, versus uniform distributions. The laser shaping effects on longitudinal phase space are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT034
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WEP2PT050	Status of CAEP THz Free Electron Laser Oscillator	ion, FEL, electron, free-electron-laser	154
	M. Li, T.H. He, C.L. Lao, P. Li, S.F. Lin, X. Luo, Q. Pan, L.J. Shan, X. Shen, H. Wang, J. Wang, D. Wu, D.X. Xiao, Y. Xu, X. Yang, P. Zhang, K. Zhou CAEP/IAE, Mianyang, Sichuan, People's Republic of China
	China Academy of Engineering Physics tera-hertz free electron laser (CAEP THz FEL, CTFEL) is the first THz FEL oscillator in China, which was jointly built by CAEP, Peking university and Tsinghua university. The stimulated saturation of the CTFEL was reached in August, 2017. This THz FEL facility consists of a GaAs photocathode high-voltage DC gun, a superconducting RF linac, a planar undulator and a quasi-concentric optical resonator. The terahertz laser's frequency is continuous adjustable from 2 THz to 3 THz. The average power is more than 10 W and the micro-pulse power is more than 0.1 MW.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT050
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THP2WB04	Laser Seeding of Electron Bunches for Future Ring-Based Light Sources	ion, electron, radiation, storage-ring	177
	S. Khan, B. Büsing, N.M. Lockmann, C. Mai, A. Meyer auf der Heide, B. Riemann, B. Sawadski, M. Schmutzler, P. Ungelenk DELTA, Dortmund, Germany
	Funding: Funded by BMBF (05K16PEA, 05K16PEB), MERCUR (Pr-2014-0047), DFG (INST 212/236-1 FUGG) and the Land NRW. In contrast to free-electron lasers (FELs), ring-based light sources are limited in intensity by incoherent emission and in pulse duration by the bunch length. However, FEL seeding schemes can be adopted to generate intense and ultrashort radiation pulses in storage rings by creating laser-induced microbunches within a short slice of the electron bunch. Microbunching gives rise to coherent emission at harmonics of the seed wavelength. In addition, terahertz (THz) radiation is coherently emitted over many turns. At DELTA, a storage ring operated by the TU Dortmund University, coherent harmonic generation (CHG) with single and double 40-fs pulses is routinely performed at seed wavelengths of 800 and 400 nm. Seeding with intensity-modulated pulses to generate tunable narrowband THz radiation is also studied. As a preparation for echo-enabled harmonic generation (EEHG), simultaneous seeding with 800/400-nm pulses in two undulators has been demonstrated. The DELTA storage ring is an excellent testbed to study many aspects of laser seeding and related diagnostics. In addition to short-pulse generation, steady-state microbunching at ring-based light sources will be discussed in the paper.
	Slides THP2WB04 [5.103 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-THP2WB04
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUA2WC01

Transportation and Manipulation of a Laser Plasma Acceleration Beam

ion, electron, undulator, plasma

56

A. Ghaith, T. André, I.A. Andriyash, F. Blache, F. Bouvet, F. Briquez, M.-E. Couprie, Y. Dietrich, J.P. Duval, C. Herbeaux, N. Hubert, C.A. Kitegi, M. Labat, N. Leclercq, A. Lestrade, A. Loulergue, O. Marcouillé, F. Marteau, D. Oumbarek, P. Rommeluère, E. Roussel, M. Sebdaoui, K.T. Tavakoli, M. Valléau
SOLEIL, Gif-sur-Yvette, France
S. Bielawski, C. Evain, C. Szwaj
PhLAM/CERLA, Villeneuve d'Ascq, France
S. Corde, J. Gautier, G. Lambert, B. Mahieu, V. Malka, K.T. Phuoc, C. Thaury
LOA, Palaiseau, France

Funding: European Research Council advanced grant COXINEL - 340015
The ERC Advanced Grant COXINEL aims at demonstrating free electron laser amplification, at a resonant wavelength of 200 nm, based on a laser plasma acceleration source. To achieve the amplification, a 10 m long dedicated transport line was designed to manipulate the beam qualities. It starts with a triplet of permanent magnet with tunable gradient quadrupoles (QUAPEVA) that handles the highly divergent electron beam, a demixing chicane with a slit to reduce the energy spread per slice, and a set of electromagnetic quadrupoles to provide a chromatic focusing in a 2 m long cryogenic undulator. Electrons of energy 176 MeV were successfully transported throughout the line, where the beam positioning and dispersion were controlled efficiently thanks to a specific beam based alignment method, as well as the energy range by varying the slit width. Observations of undulator radiation for different undulator gaps are reported.

Slides TUA2WC01 [2.465 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-TUA2WC01

Export •

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WEA1PL02

Dielectric Accelerators and Other Non-Plasma Accelerator Based Compact Light Sources

ion, undulator, electron, radiation

74

R.J. England, Z. Huang
SLAC, Menlo Park, California, USA

Funding: U.S. Department of Energy DE-AC02-76SF00515; Gordon and Betty Moore Foundation GBMF4744
We review recent experimental progress in developing nanofabricated dielectric laser-driven accelerators and discuss the possibility of utilizing the unique sub-femtosecond electron pulse format these accelerators would provide to create ultra-compact EUV and X-ray radiation sources.

Slides WEA1PL02 [16.828 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEA1PL02

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WEA1PL03

Attosecond Timing

ion, timing, FEL, electron

79

F.X. Kärtner
Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany
K. Shafak
CFEL, Hamburg, Germany
K. Shafak
Cycle GmbH, Hamburg, Germany
M. Xin
DESY, Hamburg, Germany

Funding: This work was supported by DESY and the European Research Council under the European Union's Seventh Framework Program (FP/2007-2013) / ERC Grant Agreement No. 609920.
Photon-science facilities such as X-ray free-electron lasers (XFELs) and intense-laser facilities are emerging world-wide with some of them producing sub-fs X-ray pulses. These facilities are in need of a high-precision timing distribution system, which can synchronize various microwave and optical sub-sources across multi-km distances with attosecond precision. Here, we report on a synchronous laser-microwave network that permits attosecond precision across km-scale distances. This was achieved by developing new ultrafast timing metrology devices and carefully balancing the fiber nonlinearities and fundamental noise contributions in the system. New polarization-noise-suppressed balanced optical crosscorrelators and free-space-coupled balanced optical-microwave phase detectors for improved noise performance have been implemented. Residual second- and third-order dispersion in the fiber links are carefully compensated with additional dispersion-compensating fiber to suppress link-induced Gordon-Haus jitter and to minimize output pulse duration; the link power is stabilized to minimize the nonlinearity-induced jitter as well as to maximize the signal to noise ratio for locking.

Slides WEA1PL03 [5.888 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEA1PL03

Export •

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

WEA2WD01

QUAPEVA: Variable High Gradient Permanent Magnet Quadrupole

ion, quadrupole, electron, multipole

89

C.A. Kitegi, T. André, M.-E. Couprie, A. Ghaith, J. Idam, A. Loulergue, F. Marteau, D. Oumbarek, M. Sebdaoui, M. Valléau, J. Vétéran
SOLEIL, Gif-sur-Yvette, France
C. Benabderrahmane, J. Chavanne, G. Le Bec
ESRF, Grenoble, France
O. Cosson, F. Forest, P. Jivkov, J.L. Lancelot
Sigmaphi, Vannes, France
P. N'gotta
MAX IV Laboratory, Lund University, Lund, Sweden
C. Vallerand
LAL, Orsay, France

We present the magnetic and the mechanical design of tunable high gradient permanent magnet (PM) quadrupoles. The tunable gradient of the so-called QUAPEVAS extends from 100T/m up to 200T/m. Seven of them with various lengths, ranging from 26mm up to 100mm, for different integrated quadrupole strengths were manufactured. The measured magnetic performance of these devices is also reported. These devices were successfully developed to transport laser plasma accelerated electron beam. Such applications have however less stringent multipole harmonic content constraints than diffraction limited Light sources. Trails for lowering the multipole harmonics will be discussed.

Slides WEA2WD01 [3.093 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEA2WD01

Export •

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WEP2PT008

Microbunching Instability Study in the Linac-Driven FERMI FEL Spreader Beam Line

ion, linac, FEL, electron

108

S. Di Mitri, S. Spampinati
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Suppression of microbunching instability (MBI) along high brightness electron beam delivery systems is a priority for Free Electron lasers (FELs) aiming at very narrow bandwidth. The impact of MBI on FEL spectral brilliance is aggravated by the growing demand for multi-user FEL facilities, which adopt multi-bend switchyard lines traversed by high charge density electron beams. This study provides practical guidelines to switchyards design largely immune to MBI, by focusing on the FERMI FEL Spreader line. First, two MBI analytical models [1, 2] are successfully benchmarked along the accelerator. Being the second model flexible enough to describe an arbitrary multi-bend line, and found it in agreement with particle tracking and experimental results, it was used to demonstrate that a newly proposed Spreader optics provides unitary MBI gain while preserving the electron beam brightness.
[1] Z. Huang and K.-J. Kim, Phys. Rev. Special Topics - Accel. Beams 5, 074401 (2002)
[2] R.A. Bosch, K.J. Kleman, and J. Wu, Phys. Rev. Special Topics - Accel. Beams 11, 090702 (2008)

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT008

Export •

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WEP2PT034

Beyond Uniform Ellipsoidal Laser Shaping for Beam Brightness Improvements at PITZ

ion, emittance, flattop, simulation

146

H.J. Qian, J.D. Good, C. Koschitzki, M. Krasilnikov, F. Stephan
DESY Zeuthen, Zeuthen, Germany

In the last decades, photoinjector brightness has improved significantly, driven by the needs of free electron lasers and many other applications. One of the key elements is photocathode laser shaping for reducing emittance growth from nonlinear space charge forces. At the photoinjector test facility at DESY in Zeuthen (PITZ), a uniform flattop laser was used to achieve record low emittance for a bunch charge from 20 pC to 1 nC. Due to the ideal 3D space charge force linearization in ellipsoidal electron bunches, uniform ellipsoidal photocathode laser shaping were proposed to improve beam emittance up to 33% for 1 nC beam at PITZ. In this paper, we will show even further transverse emittance improvements in simulations for both flattop and ellipsoidal laser pulses with parabolic radial distribution, versus uniform distributions. The laser shaping effects on longitudinal phase space are also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT034

Export •

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

WEP2PT050

Status of CAEP THz Free Electron Laser Oscillator

ion, FEL, electron, free-electron-laser

154

M. Li, T.H. He, C.L. Lao, P. Li, S.F. Lin, X. Luo, Q. Pan, L.J. Shan, X. Shen, H. Wang, J. Wang, D. Wu, D.X. Xiao, Y. Xu, X. Yang, P. Zhang, K. Zhou
CAEP/IAE, Mianyang, Sichuan, People's Republic of China

China Academy of Engineering Physics tera-hertz free electron laser (CAEP THz FEL, CTFEL) is the first THz FEL oscillator in China, which was jointly built by CAEP, Peking university and Tsinghua university. The stimulated saturation of the CTFEL was reached in August, 2017. This THz FEL facility consists of a GaAs photocathode high-voltage DC gun, a superconducting RF linac, a planar undulator and a quasi-concentric optical resonator. The terahertz laser's frequency is continuous adjustable from 2 THz to 3 THz. The average power is more than 10 W and the micro-pulse power is more than 0.1 MW.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-WEP2PT050

Export •

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

THP2WB04

Laser Seeding of Electron Bunches for Future Ring-Based Light Sources

ion, electron, radiation, storage-ring

177

S. Khan, B. Büsing, N.M. Lockmann, C. Mai, A. Meyer auf der Heide, B. Riemann, B. Sawadski, M. Schmutzler, P. Ungelenk
DELTA, Dortmund, Germany

Funding: Funded by BMBF (05K16PEA, 05K16PEB), MERCUR (Pr-2014-0047), DFG (INST 212/236-1 FUGG) and the Land NRW.
In contrast to free-electron lasers (FELs), ring-based light sources are limited in intensity by incoherent emission and in pulse duration by the bunch length. However, FEL seeding schemes can be adopted to generate intense and ultrashort radiation pulses in storage rings by creating laser-induced microbunches within a short slice of the electron bunch. Microbunching gives rise to coherent emission at harmonics of the seed wavelength. In addition, terahertz (THz) radiation is coherently emitted over many turns. At DELTA, a storage ring operated by the TU Dortmund University, coherent harmonic generation (CHG) with single and double 40-fs pulses is routinely performed at seed wavelengths of 800 and 400 nm. Seeding with intensity-modulated pulses to generate tunable narrowband THz radiation is also studied. As a preparation for echo-enabled harmonic generation (EEHG), simultaneous seeding with 800/400-nm pulses in two undulators has been demonstrated. The DELTA storage ring is an excellent testbed to study many aspects of laser seeding and related diagnostics. In addition to short-pulse generation, steady-state microbunching at ring-based light sources will be discussed in the paper.

Slides THP2WB04 [5.103 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FLS2018-THP2WB04

Export •

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