IPAC2018 - List of Authors (Deng, H.X.)

Paper	Title	Page
THPMK053	Simulation for LCLS-II Hard X-ray Self Seeding Scheme	4406
	C. Yang, Y. Feng, J. Krzywinski, T.O. Raubenheimer, C.-Y. Tsai, J. Wu, M. Yoon, G. Zhou SLAC, Menlo Park, California, USA H.X. Deng SINAP, Shanghai, People's Republic of China D.H. He USTC/NSRL, Hefei, Anhui, People's Republic of China Y. Hong, B. Yang University of Texas at Arlington, Arlington, USA X.F. Wang CIAE, Beijing, People's Republic of China M. Yoon POSTECH, Pohang, Kyungbuk, Republic of Korea G. Zhou IHEP, Beijing, People's Republic of China
	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. Typical SASE FELs have poor temporal coherence because of starting from shot noise. Self-seeding scheme is an approach to improve the longitudinal coherence. The single crystal monochromator self-seeding has been in successful operation in LCLS. For the high repetition rate LCLS-II machine, for damage consideration, it was initially proposed to have a two-stage self-seeding scheme, yet we have found the two-stage self-seeding scheme has no advantage over one-stage self-seeding scheme. In this paper, we investigate the optimal self-seeding conﬁguration of LCLS-II for different photon energies, and present a comparison between one-stage and two-stage self-seeding scheme of LCLS-II.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK053
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THPMK055	Self Seeding Scheme for LCLS-II-HE	4414
	C. Yang, Y. Feng, J. Krzywinski, T.O. Raubenheimer, C.-Y. Tsai, J. Wu, M. Yoon, G. Zhou SLAC, Menlo Park, California, USA H.X. Deng, X.F. Wang SINAP, Shanghai, People's Republic of China D.H. He USTC/NSRL, Hefei, Anhui, People's Republic of China Y. Hong, B. Yang University of Texas at Arlington, Arlington, USA M. Yoon POSTECH, Pohang, Kyungbuk, Republic of Korea G. Zhou IHEP, Beijing, People's Republic of China
	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 reliable approach to generate fully coherent FEL pulses. Hard X-ray self-seeding can be realized by using a single crystal in Bragg transmission geometry. However, for a high repetition rate machine, the heat load on the crystal may become an issue. In this paper, we will study the facility performance of LCLS-II-HE by numerical simulations, and discuss the heat load and optimal undulator baseline conﬁguration of LCLS-II-HE self-seeding scheme, and study the emittance tolerance of the LCLS-II-HE.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK055
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THPMK068	High degree circular polarization at x-ray self-seeding FELs with crossed-planar undulators	4453
	K. Li, H.X. Deng, Z.F. Gao, B. Liu, D. Wang SINAP, Shanghai, People's Republic of China
	Funding: Work was supported by the National Natural Science Foundation of China (11775293), the National Key Research and Development Program of China (2016YFA0401900). The crossed undulator configuration for a high-gain free-electron laser (FEL) is well-known for the ability of versatile polarization control. However, the degree of polarization is very sensitive to power and phase between the two stages of crossed undulators. In this poster, we introduce the generation of high degree circular polarization hard x-ray FEL with crossed-planar undulator seeded by self-seeding. The reverse taper and taper undulator technology are employed for improving its performance. With the combination of high degree (>95%) circular polarization and flexibility of polarization switching, this scheme might be useful for some scientific research in the future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK068
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THPMK069	Design of the Beam Switchyard of a Soft X-ray FEL User Facility in Shanghai	4456
	S. Chen, H.X. Deng, C. Feng, B. Liu, D. Wang, R. Wang SINAP, Shanghai, People's Republic of China
	A soft X-ray FEL user facility, which is based on the existing test facility located in the Zhangjiang Campus of SINAP, is under construction. Two undulator lines will be installed parallelly in the undulator hall and their electron beams are served by a 1.5 GeV linac. For simultaneous operation of the two undulator lines, a beam distribution system should be used to connect the linac and the undulator lines. In this paper, the physics design of this beam distribution system will be presented and also the beam dynamic issues will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK069
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Paper

Title

Page

Simulation for LCLS-II Hard X-ray Self Seeding Scheme

4406

C. Yang, Y. Feng, J. Krzywinski, T.O. Raubenheimer, C.-Y. Tsai, J. Wu, M. Yoon, G. Zhou
SLAC, Menlo Park, California, USA
H.X. Deng
SINAP, Shanghai, People's Republic of China
D.H. He
USTC/NSRL, Hefei, Anhui, People's Republic of China
Y. Hong, B. Yang
University of Texas at Arlington, Arlington, USA
X.F. Wang
CIAE, Beijing, People's Republic of China
M. Yoon
POSTECH, Pohang, Kyungbuk, Republic of Korea
G. Zhou
IHEP, Beijing, People's Republic of China

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.
Typical SASE FELs have poor temporal coherence because of starting from shot noise. Self-seeding scheme is an approach to improve the longitudinal coherence. The single crystal monochromator self-seeding has been in successful operation in LCLS. For the high repetition rate LCLS-II machine, for damage consideration, it was initially proposed to have a two-stage self-seeding scheme, yet we have found the two-stage self-seeding scheme has no advantage over one-stage self-seeding scheme. In this paper, we investigate the optimal self-seeding conﬁguration of LCLS-II for different photon energies, and present a comparison between one-stage and two-stage self-seeding scheme of LCLS-II.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK053

Export •

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

THPMK055

Self Seeding Scheme for LCLS-II-HE

4414

C. Yang, Y. Feng, J. Krzywinski, T.O. Raubenheimer, C.-Y. Tsai, J. Wu, M. Yoon, G. Zhou
SLAC, Menlo Park, California, USA
H.X. Deng, X.F. Wang
SINAP, Shanghai, People's Republic of China
D.H. He
USTC/NSRL, Hefei, Anhui, People's Republic of China
Y. Hong, B. Yang
University of Texas at Arlington, Arlington, USA
M. Yoon
POSTECH, Pohang, Kyungbuk, Republic of Korea
G. Zhou
IHEP, Beijing, People's Republic of China

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 reliable approach to generate fully coherent FEL pulses. Hard X-ray self-seeding can be realized by using a single crystal in Bragg transmission geometry. However, for a high repetition rate machine, the heat load on the crystal may become an issue. In this paper, we will study the facility performance of LCLS-II-HE by numerical simulations, and discuss the heat load and optimal undulator baseline conﬁguration of LCLS-II-HE self-seeding scheme, and study the emittance tolerance of the LCLS-II-HE.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK055

Export •

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

THPMK068

High degree circular polarization at x-ray self-seeding FELs with crossed-planar undulators

4453

K. Li, H.X. Deng, Z.F. Gao, B. Liu, D. Wang
SINAP, Shanghai, People's Republic of China

Funding: Work was supported by the National Natural Science Foundation of China (11775293), the National Key Research and Development Program of China (2016YFA0401900).
The crossed undulator configuration for a high-gain free-electron laser (FEL) is well-known for the ability of versatile polarization control. However, the degree of polarization is very sensitive to power and phase between the two stages of crossed undulators. In this poster, we introduce the generation of high degree circular polarization hard x-ray FEL with crossed-planar undulator seeded by self-seeding. The reverse taper and taper undulator technology are employed for improving its performance. With the combination of high degree (>95%) circular polarization and flexibility of polarization switching, this scheme might be useful for some scientific research in the future.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK068

Export •

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

THPMK069

Design of the Beam Switchyard of a Soft X-ray FEL User Facility in Shanghai

4456

S. Chen, H.X. Deng, C. Feng, B. Liu, D. Wang, R. Wang
SINAP, Shanghai, People's Republic of China

A soft X-ray FEL user facility, which is based on the existing test facility located in the Zhangjiang Campus of SINAP, is under construction. Two undulator lines will be installed parallelly in the undulator hall and their electron beams are served by a 1.5 GeV linac. For simultaneous operation of the two undulator lines, a beam distribution system should be used to connect the linac and the undulator lines. In this paper, the physics design of this beam distribution system will be presented and also the beam dynamic issues will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK069

Export •

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