FEL2017 - List of Authors (Kang, H.-S.)

Paper	Title	Page
MOC01	0.1-nm FEL Lasing of PAL-XFEL
	H.-S. Kang, H. Heo, C. Kim, G. Kim, C.-K. Min, H. Yang PAL, Pohang, Kyungbuk, Republic of Korea
	The hard X-ray free electron laser at Pohang Accelerator Laboratory (PAL-XFEL) achieved saturation of a 0.144-nm free electron laser (FEL) beam on November 27, 2016, making it the third hard X-ray FEL in the world, following LCLS in 2009 and SACLA in 2011. On February 2, 2017, a saturated 1.52-nm FEL beam was also achieved in the soft X-ray FEL line with an electron beam energy of 3.0 GeV. Finally, saturation of a 0.104-nm FEL beam was achieved on March 16, 2017 using an electron beam energy of 9.47 GeV and K = 1.87. In this paper we present the commissioning result of PAL-XFEL as well as the beamline commissioning results.
	Slides MOC01 [7.020 MB]
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MOP001	Diamond Double-Crystal System for a Forward Bragg Diffraction X-Ray Monochromator of the Self-Seeded PAL XFEL	29
	Yu. Shvyd'ko, J.W.J. Anton, S.P. Kearney, K.-J. Kim, T. Kolodziej, D. Shu ANL, Argonne, Illinois, USA V.D. Blank, S. Terentiev TISNCM, Troitsk, Russia H.-S. Kang, C.-K. Min, B.G. Oh PAL, Pohang, Kyungbuk, Republic of Korea P. Vodnala Northern Illinois University, DeKalb, Illinois, USA
	An x-ray monochromator for a hard x-ray self-seeding system is planned at PAL XFEL to be used in a 3-keV to 10-keV photon spectral range. The monochromatization in a 5 keV to 7 keV range will be achieved by forward Bragg diffraction (FBD) from a 30-micron-thin diamond crystal in the [110] orientation employing the (220) symmetric Bragg reflection. FBD from the same crystal using the (111) asymmetric Bragg reflection will provide monochromatization in a 3 keV to 5 keV spectral range. In the 7-keV to 10-keV spectral range, a 100-micron crystal in the [100] orientation will be used employing FBD with the (400) symmetric Bragg reflection. Two almost defect-free diamond crystals in the required orientations and thicknesses are mounted in a strain-free mechanically-stable fashion on a common CVD diamond substrate using all-diamond components, ensuring radiation-safe XFEL operations with improved heat transport. We will present results of the optical and engineering designs, manufacturing, and x-ray diffraction topography characterization of the diamond double-crystal system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP001
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TUP058	Slippage-Enhanced SASE FEL	348
	J. Wu, A. Brachmann, K. Fang, A. Marinelli, C. Pellegrini, T.O. Raubenheimer, C.-Y. Tsai, C. Yang, M. Yoon, G. Zhou SLAC, Menlo Park, California, USA H.-S. Kang, G. Kim, I.H. Nam PAL, Pohang, Republic of Korea 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. High-brightness XFEL is demanding for many users, in particular for certain types of imaging applications. Seeded FELs including self-seeding XFELs were successfully demonstrated. Alternative approaches by enhancing slippage between the x-ray pulse and the electron bunch were also demonstrated. This class of Slippage-enhanced SASE (SeSASE) schemes can be unique for FEL spectral range between 1.5 keV to 4 keV where neither grating-based soft x-ray self-seeding nor crystal-based hard x-ray self-seeding can easily access. SeSASE can provide high-brightness XFEL for high repetition rate machines not suffering from heat load on the crystal monochromator. We report start-to-end simulation results for LCLS-II project and PAL-XFEL project with study on tolerance. Performance comparison between SaSASE FEL and self-seeding FEL in the overlapping frequency range is also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUP058
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WEC04	Progress of PAL-XFEL Undulator Program
	D.E. Kim, H.-S. Kang, K.-H. Park PAL, Pohang, Kyungbuk, Republic of Korea I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) recently commissioned and started early user service of 0.1 nm SASE-based FEL based on the 10 GeV S-band linear accelerator named PAL-XFEL. One of the key components of the PAL-XFEL is the undulator system which consists of 20 units of Hard X-ray undulators, and 7 units Soft X-ray FELs. The basic design concept is based on the EU-XFEL undulator, but it also requires modification reflecting PAL-XFEL requirements. In this report, PAL efforts to modify, re-design, manufacture, take measurements, tune, install, and commission the undulator system will be summarized.
	Slides WEC04 [2.697 MB]
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WEP019	High Stable Pulse Modulator for PAL-XFEL*	460
	S.S. Park, H.-S. Kang, S.H. Kim, H.-S. Lee PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: Work supported by Ministry of Science, ICT(Information/Communication Technology) and Future Planning. The XFEL of Pohang Accelerator Laboratory (PAL) commissioned the 10 GeV PAL-XFEL project in 2015. The PAL-XFEL needs a highly-stable electron beam. The very stable beam voltage of a klystron-modulator is essential to provide the stable acceleration field for an electron beam. Thus, the modulator system for the XFEL requires less than 50 ppm PFN voltage stability. To get this high stability on the modulator system, the HVPS of inverter type is an important component. The modulator also needs lower noise and more smart. In this paper, we will discuss the design and the test results of the high-stability pulse modulator system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-WEP019
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WEP041	HLS to Measure Changes in Real Time in the Ground and Building Floor of PAL-XFEL, Large-Scale Scientific Equipment	503
	H. J. Choi, J.H. Han, H.-S. Kang, S.H. Kim, H.-G. Lee, S.B. Lee PAL, Pohang, Kyungbuk, Republic of Korea
	A variety of parts that comprise large-scale scientific equipment should be installed and operated at accurate three-dimensional location coordinates (X, Y, Z) through survey and alignment in order to ensure optimal performance. However, uplift or subsidence of the ground occurs over time, and consequently causes the deformation of building floors. The deformation of the ground and buildings cause changes in the location of installed parts, eventually leading to alignment errors (ΔX, ΔY, ΔZ) of components. As a result, the parameters of the system change and the performance of large-scale scientific equipment is degraded. Alignment errors that result from changes in building floor height can be predicted by real-time measurement of changes in building floors. This produces the advantage of reducing survey and alignment time by selecting the region where great changes in building floor height are shown and re-aligning components in the region in a short time. To do so, HLS (hydrostatic leveling sensor) with a resolution of 0.2 micrometers and a waterpipe of 1 km are installed at the PAL-XFEL building. This paper introduces the installation and operation status of HLS.
	Poster WEP041 [0.832 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-WEP041
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Paper

Title

Page

MOC01

0.1-nm FEL Lasing of PAL-XFEL

H.-S. Kang, H. Heo, C. Kim, G. Kim, C.-K. Min, H. Yang
PAL, Pohang, Kyungbuk, Republic of Korea

The hard X-ray free electron laser at Pohang Accelerator Laboratory (PAL-XFEL) achieved saturation of a 0.144-nm free electron laser (FEL) beam on November 27, 2016, making it the third hard X-ray FEL in the world, following LCLS in 2009 and SACLA in 2011. On February 2, 2017, a saturated 1.52-nm FEL beam was also achieved in the soft X-ray FEL line with an electron beam energy of 3.0 GeV. Finally, saturation of a 0.104-nm FEL beam was achieved on March 16, 2017 using an electron beam energy of 9.47 GeV and K = 1.87. In this paper we present the commissioning result of PAL-XFEL as well as the beamline commissioning results.

Slides MOC01 [7.020 MB]

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MOP001

Diamond Double-Crystal System for a Forward Bragg Diffraction X-Ray Monochromator of the Self-Seeded PAL XFEL

29

Yu. Shvyd'ko, J.W.J. Anton, S.P. Kearney, K.-J. Kim, T. Kolodziej, D. Shu
ANL, Argonne, Illinois, USA
V.D. Blank, S. Terentiev
TISNCM, Troitsk, Russia
H.-S. Kang, C.-K. Min, B.G. Oh
PAL, Pohang, Kyungbuk, Republic of Korea
P. Vodnala
Northern Illinois University, DeKalb, Illinois, USA

An x-ray monochromator for a hard x-ray self-seeding system is planned at PAL XFEL to be used in a 3-keV to 10-keV photon spectral range. The monochromatization in a 5 keV to 7 keV range will be achieved by forward Bragg diffraction (FBD) from a 30-micron-thin diamond crystal in the [110] orientation employing the (220) symmetric Bragg reflection. FBD from the same crystal using the (111) asymmetric Bragg reflection will provide monochromatization in a 3 keV to 5 keV spectral range. In the 7-keV to 10-keV spectral range, a 100-micron crystal in the [100] orientation will be used employing FBD with the (400) symmetric Bragg reflection. Two almost defect-free diamond crystals in the required orientations and thicknesses are mounted in a strain-free mechanically-stable fashion on a common CVD diamond substrate using all-diamond components, ensuring radiation-safe XFEL operations with improved heat transport. We will present results of the optical and engineering designs, manufacturing, and x-ray diffraction topography characterization of the diamond double-crystal system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP001

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

TUP058

Slippage-Enhanced SASE FEL

348

J. Wu, A. Brachmann, K. Fang, A. Marinelli, C. Pellegrini, T.O. Raubenheimer, C.-Y. Tsai, C. Yang, M. Yoon, G. Zhou
SLAC, Menlo Park, California, USA
H.-S. Kang, G. Kim, I.H. Nam
PAL, Pohang, Republic of Korea
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.
High-brightness XFEL is demanding for many users, in particular for certain types of imaging applications. Seeded FELs including self-seeding XFELs were successfully demonstrated. Alternative approaches by enhancing slippage between the x-ray pulse and the electron bunch were also demonstrated. This class of Slippage-enhanced SASE (SeSASE) schemes can be unique for FEL spectral range between 1.5 keV to 4 keV where neither grating-based soft x-ray self-seeding nor crystal-based hard x-ray self-seeding can easily access. SeSASE can provide high-brightness XFEL for high repetition rate machines not suffering from heat load on the crystal monochromator. We report start-to-end simulation results for LCLS-II project and PAL-XFEL project with study on tolerance. Performance comparison between SaSASE FEL and self-seeding FEL in the overlapping frequency range is also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUP058

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WEC04

Progress of PAL-XFEL Undulator Program

D.E. Kim, H.-S. Kang, K.-H. Park
PAL, Pohang, Kyungbuk, Republic of Korea
I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) recently commissioned and started early user service of 0.1 nm SASE-based FEL based on the 10 GeV S-band linear accelerator named PAL-XFEL. One of the key components of the PAL-XFEL is the undulator system which consists of 20 units of Hard X-ray undulators, and 7 units Soft X-ray FELs. The basic design concept is based on the EU-XFEL undulator, but it also requires modification reflecting PAL-XFEL requirements. In this report, PAL efforts to modify, re-design, manufacture, take measurements, tune, install, and commission the undulator system will be summarized.

Slides WEC04 [2.697 MB]

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WEP019

High Stable Pulse Modulator for PAL-XFEL*

460

S.S. Park, H.-S. Kang, S.H. Kim, H.-S. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: Work supported by Ministry of Science, ICT(Information/Communication Technology) and Future Planning.
The XFEL of Pohang Accelerator Laboratory (PAL) commissioned the 10 GeV PAL-XFEL project in 2015. The PAL-XFEL needs a highly-stable electron beam. The very stable beam voltage of a klystron-modulator is essential to provide the stable acceleration field for an electron beam. Thus, the modulator system for the XFEL requires less than 50 ppm PFN voltage stability. To get this high stability on the modulator system, the HVPS of inverter type is an important component. The modulator also needs lower noise and more smart. In this paper, we will discuss the design and the test results of the high-stability pulse modulator system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-WEP019

Export •

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

WEP041

HLS to Measure Changes in Real Time in the Ground and Building Floor of PAL-XFEL, Large-Scale Scientific Equipment

503

H. J. Choi, J.H. Han, H.-S. Kang, S.H. Kim, H.-G. Lee, S.B. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

A variety of parts that comprise large-scale scientific equipment should be installed and operated at accurate three-dimensional location coordinates (X, Y, Z) through survey and alignment in order to ensure optimal performance. However, uplift or subsidence of the ground occurs over time, and consequently causes the deformation of building floors. The deformation of the ground and buildings cause changes in the location of installed parts, eventually leading to alignment errors (ΔX, ΔY, ΔZ) of components. As a result, the parameters of the system change and the performance of large-scale scientific equipment is degraded. Alignment errors that result from changes in building floor height can be predicted by real-time measurement of changes in building floors. This produces the advantage of reducing survey and alignment time by selecting the region where great changes in building floor height are shown and re-aligning components in the region in a short time. To do so, HLS (hydrostatic leveling sensor) with a resolution of 0.2 micrometers and a waterpipe of 1 km are installed at the PAL-XFEL building. This paper introduces the installation and operation status of HLS.

Poster WEP041 [0.832 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-WEP041

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