FEL2019 - List of Authors (Liu, S.)

Paper	Title	Page
TUA01	Parallel Operation of SASE1 and SASE3 at the European XFEL	25
	S. Liu, F. Brinker, W. Decking, L. Fröhlich, R. Kammering, D. Nölle, F. Obier, E. Schneidmiller, M. Scholz, T. Wilksen, M.V. Yurkov DESY, Hamburg, Germany R. Boll, N. Gerasimova, T. Mazza, M. Meyer, A. Scherz, H. Sinn EuXFEL, Schenefeld, Germany
	At the European XFEL a hard X-Ray SASE FEL (SA-SE1) and a soft X-Ray SASE FEL (SASE3) share in series the same electron beamline. This configuration couples the operation conditions for both undulators and their subsequent user experiments in terms of SASE in-tensity and background. We report on our experience in parallel operation and discuss the solutions that enable the operation of both undulators as independently as possible.
	Slides TUA01 [13.809 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUA01
About •	paper received ※ 26 August 2019 paper accepted ※ 17 October 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA04	Harmonic Lasing Experiment at the European XFEL	29
	E. Schneidmiller, F. Brinker, W. Decking, M.W. Guetg, S. Liu, D. Nölle, M. Scholz, M.V. Yurkov, I. Zagorodnov DESY, Hamburg, Germany G. Geloni, N. Gerasimova, J. Grünert, S. Karabekyan, N.G. Kujala, J. Laksman, Y. Li, J. Liu, Th. Maltezopoulos, I. Petrov, L. Samoylova, S. Serkez, H. Sinn, F. Wolff-Fabris EuXFEL, Hamburg, Germany
	Harmonic lasing is an opportunity to extend the photon energy range of existing and planned X-ray FEL user facilities. Contrary to nonlinear harmonic generation, harmonic lasing can provide a much more intense, stable, and narrow-band FEL beam. Another interesting application is Harmonic Lasing Self-Seeding (HLSS) that allows to improve the longitudinal coherence and spectral power of a Self-Amplified Spontaneous Emission (SASE) FEL. This concept was successfully tested at FLASH in the range of 4.5 - 15 nm and at PAL XFEL at 1 nm. In this contribution we present recent results from the European XFEL where we successfully demonstrated operation of HLSS FEL at 5.9 Angstrom and 2.8 Angstrom, in the latter case obtaining both 3rd and 5th harmonic lasing.
	Slides TUA04 [1.174 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUA04
About •	paper received ※ 20 August 2019 paper accepted ※ 29 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP079	Status of the Hard X-Ray Self-Seeding Setup at the European XFEL	242
	G. Geloni, S. Karabekyan, D. La Civita, L. Samoylova, S. Serkez, R. Shayduk, H. Sinn, V. Sleziona, M. Vannoni, M. Yakopov EuXFEL, Schenefeld, Germany J.W.J. Anton, S.P. Kearney, D. Shu ANL, Lemont, Illinois, USA V.D. Blank, S. Terentiev TISNCM, Troitsk, Russia W. Decking, V. Kocharyan, S. Liu, E. Negodin, E. Saldin, T. Wohlenberg DESY, Hamburg, Germany X. Dong European X-Ray Free-Electron Laser Facility GmbH, Schelefeld, Germany
	A Hard X-Ray Self-Seeding (HXRSS) setup will be soon commissioned at the European XFEL. It relies on a two-chicanes scheme to deal, in particular, with the high pulse repetition rate of the facility. In this contribution we review the physics choices made at the design stage and the expected performance of the setup. We will also focus on the description of the hardware installations made at the SASE2 line of the European XFEL.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUP079
About •	paper received ※ 27 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEB01	Identification and Mitigation of Smoke-Ring Effects in Scintillator-Based Electron Beam Images at the European XFEL	301
	G. Kube, S. Liu, A.I. Novokshonov, M. Scholz DESY, Hamburg, Germany
	Standard transverse beam profile measurements at the European XFEL are based on scintillating screen monitors using LYSO:Ce. While it is possible to resolve beam sizes down to a few micrometers with this scintillator, the experience during the XFEL commissioning showed that the measured emittance values were significantly larger than the expected ones. In addition, beam profiles measured at bunch charges of a few hundred pC showed a ’smoke ring’ structure. While coherent OTR emission and beam dynamical influence can be excluded, it is assumed that the profile distortions are caused by effects from the scintillator material. Following the experience in high energy physics, a simple model was developed which takes into account quenching effects of excitonic carriers inside a scintillator in a heuristic way. Based on this model, the observed beam profiles can be understood qualitatively. Together with the model description, first comparisons with experimental results will be shown. Possible new scintillator materials suitable for beam profile diagnostics and first test results from beam measurements will be presented.
	Slides WEB01 [5.057 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEB01
About •	paper received ※ 20 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP008	Multi-Beamline Operation at the European XFEL	335
	L. Fröhlich, A. Aghababyan, V. Balandin, B. Beutner, F. Brinker, W. Decking, N. Golubeva, O. Hensler, Y. Janik, R. Kammering, H. Kay, T. Limberg, S. Liu, D. Nölle, F. Obier, M. Omet, M. Scholz, T. Wamsat, T. Wilksen, J. Wortmann DESY, Hamburg, Germany
	The European XFEL uses a unique beam distribution scheme to direct electron bunches to its three undulator lines. The accelerator delivers up to 600 microsecond long bunch trains, out of which parts or individual bunches can be selected for photon production in any of the FELs. This contribution gives a brief overview of the kicker-septum scheme facilitating this and highlights how even complex bunch patterns can easily be configured via the timing system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP008
About •	paper received ※ 19 August 2019 paper accepted ※ 29 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Parallel Operation of SASE1 and SASE3 at the European XFEL

25

S. Liu, F. Brinker, W. Decking, L. Fröhlich, R. Kammering, D. Nölle, F. Obier, E. Schneidmiller, M. Scholz, T. Wilksen, M.V. Yurkov
DESY, Hamburg, Germany
R. Boll, N. Gerasimova, T. Mazza, M. Meyer, A. Scherz, H. Sinn
EuXFEL, Schenefeld, Germany

At the European XFEL a hard X-Ray SASE FEL (SA-SE1) and a soft X-Ray SASE FEL (SASE3) share in series the same electron beamline. This configuration couples the operation conditions for both undulators and their subsequent user experiments in terms of SASE in-tensity and background. We report on our experience in parallel operation and discuss the solutions that enable the operation of both undulators as independently as possible.

Slides TUA01 [13.809 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUA01

About •

paper received ※ 26 August 2019 paper accepted ※ 17 October 2019 issue date ※ 05 November 2019

Export •

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

TUA04

Harmonic Lasing Experiment at the European XFEL

29

E. Schneidmiller, F. Brinker, W. Decking, M.W. Guetg, S. Liu, D. Nölle, M. Scholz, M.V. Yurkov, I. Zagorodnov
DESY, Hamburg, Germany
G. Geloni, N. Gerasimova, J. Grünert, S. Karabekyan, N.G. Kujala, J. Laksman, Y. Li, J. Liu, Th. Maltezopoulos, I. Petrov, L. Samoylova, S. Serkez, H. Sinn, F. Wolff-Fabris
EuXFEL, Hamburg, Germany

Harmonic lasing is an opportunity to extend the photon energy range of existing and planned X-ray FEL user facilities. Contrary to nonlinear harmonic generation, harmonic lasing can provide a much more intense, stable, and narrow-band FEL beam. Another interesting application is Harmonic Lasing Self-Seeding (HLSS) that allows to improve the longitudinal coherence and spectral power of a Self-Amplified Spontaneous Emission (SASE) FEL. This concept was successfully tested at FLASH in the range of 4.5 - 15 nm and at PAL XFEL at 1 nm. In this contribution we present recent results from the European XFEL where we successfully demonstrated operation of HLSS FEL at 5.9 Angstrom and 2.8 Angstrom, in the latter case obtaining both 3rd and 5th harmonic lasing.

Slides TUA04 [1.174 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUA04

About •

paper received ※ 20 August 2019 paper accepted ※ 29 August 2019 issue date ※ 05 November 2019

Export •

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

TUP079

Status of the Hard X-Ray Self-Seeding Setup at the European XFEL

242

G. Geloni, S. Karabekyan, D. La Civita, L. Samoylova, S. Serkez, R. Shayduk, H. Sinn, V. Sleziona, M. Vannoni, M. Yakopov
EuXFEL, Schenefeld, Germany
J.W.J. Anton, S.P. Kearney, D. Shu
ANL, Lemont, Illinois, USA
V.D. Blank, S. Terentiev
TISNCM, Troitsk, Russia
W. Decking, V. Kocharyan, S. Liu, E. Negodin, E. Saldin, T. Wohlenberg
DESY, Hamburg, Germany
X. Dong
European X-Ray Free-Electron Laser Facility GmbH, Schelefeld, Germany

A Hard X-Ray Self-Seeding (HXRSS) setup will be soon commissioned at the European XFEL. It relies on a two-chicanes scheme to deal, in particular, with the high pulse repetition rate of the facility. In this contribution we review the physics choices made at the design stage and the expected performance of the setup. We will also focus on the description of the hardware installations made at the SASE2 line of the European XFEL.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUP079

About •

paper received ※ 27 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019

Export •

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

WEB01

Identification and Mitigation of Smoke-Ring Effects in Scintillator-Based Electron Beam Images at the European XFEL

301

G. Kube, S. Liu, A.I. Novokshonov, M. Scholz
DESY, Hamburg, Germany

Standard transverse beam profile measurements at the European XFEL are based on scintillating screen monitors using LYSO:Ce. While it is possible to resolve beam sizes down to a few micrometers with this scintillator, the experience during the XFEL commissioning showed that the measured emittance values were significantly larger than the expected ones. In addition, beam profiles measured at bunch charges of a few hundred pC showed a ’smoke ring’ structure. While coherent OTR emission and beam dynamical influence can be excluded, it is assumed that the profile distortions are caused by effects from the scintillator material. Following the experience in high energy physics, a simple model was developed which takes into account quenching effects of excitonic carriers inside a scintillator in a heuristic way. Based on this model, the observed beam profiles can be understood qualitatively. Together with the model description, first comparisons with experimental results will be shown. Possible new scintillator materials suitable for beam profile diagnostics and first test results from beam measurements will be presented.

Slides WEB01 [5.057 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEB01

About •

paper received ※ 20 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019

Export •

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

WEP008

Multi-Beamline Operation at the European XFEL

335

L. Fröhlich, A. Aghababyan, V. Balandin, B. Beutner, F. Brinker, W. Decking, N. Golubeva, O. Hensler, Y. Janik, R. Kammering, H. Kay, T. Limberg, S. Liu, D. Nölle, F. Obier, M. Omet, M. Scholz, T. Wamsat, T. Wilksen, J. Wortmann
DESY, Hamburg, Germany

The European XFEL uses a unique beam distribution scheme to direct electron bunches to its three undulator lines. The accelerator delivers up to 600 microsecond long bunch trains, out of which parts or individual bunches can be selected for photon production in any of the FELs. This contribution gives a brief overview of the kicker-septum scheme facilitating this and highlights how even complex bunch patterns can easily be configured via the timing system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP008

About •

paper received ※ 19 August 2019 paper accepted ※ 29 August 2019 issue date ※ 05 November 2019

Export •

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