FEL2017 - List of Authors (Feng, Y.)

Paper	Title	Page
MOP018	Distributed Self-Seeding Scheme for LCLS-II	68
	C. Yang, Y. Feng, T.O. Raubenheimer, C.-Y. Tsai, J. Wu, M. Yoon, G. Zhou SLAC, Menlo Park, California, USA B. Yang University of Texas at Arlington, Arlington, USA
	Funding: The work was supported by the US Department of Energy (DOE) under contract DE-AC02-76SF00515 and the US DOE Office of Science Early Career Research Program grant FWP-2013-SLAC-100164. Self-seeding is a successful approach for generating high-brightness x-ray free electron laser (XFEL). A single-crystal monochromator in-between the undulator sections to generate a coherent seed is adopted in LCLS. However, for a high-repetition rate machine like LCLS-II, the crystal monochromator in current setup cannot sustain the high average power; hence a distributed self-seeding scheme utilizing multi-stages is necessary. Based on the criteria set on the crystal, the maximum allowed x-ray energy deposited in the crystal will determine the machine configuration for such a distributed self-seeding scheme. In this paper, a distributed self-seeding configuration is optimized for LCLS-II type projects in the hard x-ray FEL energy regime. The study is carried out based on numerical simulation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP018
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MOP061	X-ray Regenerative Amplifier Free-Electron Laser Concepts for LCLS-II	192
	G. Marcus, Y. Ding, J.P. Duris, Y. Feng, Z. Huang, J. Krzywinski, T.J. Maxwell, D.F. Ratner, T.O. Raubenheimer SLAC, Menlo Park, California, USA K.-J. Kim, R.R. Lindberg, Yu. Shvyd'ko ANL, Argonne, Illinois, USA D.C. Nguyen LANL, Los Alamos, New Mexico, USA
	High-brightness electron beams that will drive the next generation of high-repetition rate X-ray FELs allow for the possibility of optical cavity-based feedback. One such cavity-based FEL concept is the Regenerative Amplifier Free-Electron Laser (RAFEL). This paper examines the design and performance of possible RAFEL configurations for LCLS-II. The results are primarily based on high-fidelity numerical particle simulations that show the production of high brightness, high average power, fully coherent, and stable X-ray pulses at LCLS-II using both the fundamental and harmonic FEL interactions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP061
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TUA05	Generating Subfemtosecond Hard X-Ray Pulses with Optimized Nonlinear Bunch Compression
	S. Huang PKU, Beijing, People's Republic of China Y. Ding, Y. Feng, E. Hemsing, Z. Huang, J. Krzywinski, A.A. Lutman, A. Marinelli, T.J. Maxwell, D. Zhu SLAC, Menlo Park, California, USA
	Funding: This work is supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515 and the National Key Research and Development Program of China (Grant No. 2016YFA0401904). A simple method for generating single-spike hard x-ray pulses in free-electron lasers (FELs) has been developed at the Linac Coherent Light Source (LCLS). By optimizing the electron bunch compression in experiments, we have obtained half of the hard x-ray FEL shots containing single-spike spectrum. At 5.6-keV photon energy, the single-spike shots have a mean pulse energy of about 10 J with 70% intensity fluctuation and the pulse width (full width at half maximum) is evaluated to be at 200-attosecond level.
	Slides TUA05 [3.854 MB]
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TUB01	Seeding Experiments and Seeding Options for LCLS II	219
	E. Hemsing, R.N. Coffee, W.M. Fawley, Y. Feng, B.W. Garcia, J.B. Hastings, Z. Huang, G. Marcus, D.F. Ratner, T.O. Raubenheimer SLAC, Menlo Park, California, USA G. Penn, R.W. Schoenlein LBNL, Berkeley, California, USA
	We discuss the present status of FEL seeding experiments toward the soft x-ray regime and on-going studies on possible seeding options for the high repetition soft x-ray line at LCLS-II. The seeding schemes include self-seeding, cascaded HGHG, and EEHG to reach the 1-2 nm regime with the highest possible brightness and minimal spectral pedestal. We describe relevant figures of merit, performance expectations, and potential issues.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUB01
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Paper

Title

Page

Distributed Self-Seeding Scheme for LCLS-II

68

C. Yang, Y. Feng, T.O. Raubenheimer, C.-Y. Tsai, J. Wu, M. Yoon, G. Zhou
SLAC, Menlo Park, California, USA
B. Yang
University of Texas at Arlington, Arlington, USA

Funding: The work was supported by the US Department of Energy (DOE) under contract DE-AC02-76SF00515 and the US DOE Office of Science Early Career Research Program grant FWP-2013-SLAC-100164.
Self-seeding is a successful approach for generating high-brightness x-ray free electron laser (XFEL). A single-crystal monochromator in-between the undulator sections to generate a coherent seed is adopted in LCLS. However, for a high-repetition rate machine like LCLS-II, the crystal monochromator in current setup cannot sustain the high average power; hence a distributed self-seeding scheme utilizing multi-stages is necessary. Based on the criteria set on the crystal, the maximum allowed x-ray energy deposited in the crystal will determine the machine configuration for such a distributed self-seeding scheme. In this paper, a distributed self-seeding configuration is optimized for LCLS-II type projects in the hard x-ray FEL energy regime. The study is carried out based on numerical simulation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP018

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

MOP061

X-ray Regenerative Amplifier Free-Electron Laser Concepts for LCLS-II

192

G. Marcus, Y. Ding, J.P. Duris, Y. Feng, Z. Huang, J. Krzywinski, T.J. Maxwell, D.F. Ratner, T.O. Raubenheimer
SLAC, Menlo Park, California, USA
K.-J. Kim, R.R. Lindberg, Yu. Shvyd'ko
ANL, Argonne, Illinois, USA
D.C. Nguyen
LANL, Los Alamos, New Mexico, USA

High-brightness electron beams that will drive the next generation of high-repetition rate X-ray FELs allow for the possibility of optical cavity-based feedback. One such cavity-based FEL concept is the Regenerative Amplifier Free-Electron Laser (RAFEL). This paper examines the design and performance of possible RAFEL configurations for LCLS-II. The results are primarily based on high-fidelity numerical particle simulations that show the production of high brightness, high average power, fully coherent, and stable X-ray pulses at LCLS-II using both the fundamental and harmonic FEL interactions.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP061

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

TUA05

Generating Subfemtosecond Hard X-Ray Pulses with Optimized Nonlinear Bunch Compression

S. Huang
PKU, Beijing, People's Republic of China
Y. Ding, Y. Feng, E. Hemsing, Z. Huang, J. Krzywinski, A.A. Lutman, A. Marinelli, T.J. Maxwell, D. Zhu
SLAC, Menlo Park, California, USA

Funding: This work is supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515 and the National Key Research and Development Program of China (Grant No. 2016YFA0401904).
A simple method for generating single-spike hard x-ray pulses in free-electron lasers (FELs) has been developed at the Linac Coherent Light Source (LCLS). By optimizing the electron bunch compression in experiments, we have obtained half of the hard x-ray FEL shots containing single-spike spectrum. At 5.6-keV photon energy, the single-spike shots have a mean pulse energy of about 10 J with 70% intensity fluctuation and the pulse width (full width at half maximum) is evaluated to be at 200-attosecond level.

Slides TUA05 [3.854 MB]

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

TUB01

Seeding Experiments and Seeding Options for LCLS II

219

E. Hemsing, R.N. Coffee, W.M. Fawley, Y. Feng, B.W. Garcia, J.B. Hastings, Z. Huang, G. Marcus, D.F. Ratner, T.O. Raubenheimer
SLAC, Menlo Park, California, USA
G. Penn, R.W. Schoenlein
LBNL, Berkeley, California, USA

We discuss the present status of FEL seeding experiments toward the soft x-ray regime and on-going studies on possible seeding options for the high repetition soft x-ray line at LCLS-II. The seeding schemes include self-seeding, cascaded HGHG, and EEHG to reach the 1-2 nm regime with the highest possible brightness and minimal spectral pedestal. We describe relevant figures of merit, performance expectations, and potential issues.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUB01

Export •

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