FEL2015 - List of Authors (Kang, H.-S.)

Paper	Title	Page
MOP016	Status of the Fabrication of PAL-XFEL Magnet Power Supplies	66
	S.-H. Jeong, Y.-G. Jung, H.-S. Kang, D.E. Kim, I.S. Ko, H.-G. Lee, S.B. Lee, B.G. Oh, K.-H. Park, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea
	PAL-XFEL has been constructing including a 10 GeV linac, hard X-ray and soft X-ray branches. PAL-XFEL required for about six hundreds of magnet power supply (MPS). The eight different prototypes of MPS are developing to confirm the performance, functions, size, heat load and so on. This paper describes the test results of the prototype MPS in major specifications. All MPSs have to be installed the end of September in 2015. The installation progress of the MPS was also described.
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MOP029	PAL XFEL Pulse Modulator System Test Results Using a High Precision CCPS	89
	S.H. Kim, H.-S. Kang, G.H. Kim, I.S. Ko, S.J. Kwon, H.-S. Lee, S.S. Park, Y.J. Park PAL, Pohang, Kyungbuk, Republic of Korea M.-H. Cho POSTECH, Pohang, Kyungbuk, Republic of Korea K.Y. Jang, H.S. Shin POSCO ICT, Gyeonggi-do, Republic of Korea D.S. Kim, S.Y. Lee, M. Seo Dawonsys, Siheung-City, Republic of Korea
	PAL XFEL is supposed to install 51 units of the pulse modulator power supplies for a 10-GeV linear accelerator using S-band (2856 MHz) cavities. The requirements of the modulator stability really become very tight. The stability on beam voltage is required to be less than 50 ppm. In order to obtain the high precision stability from the modulator system, we have newly produced a capacitor charging power supply (CCPS) and obtained the target stability with 10 ppm (STD) accuracy from measuring PFN (Pulse Forming Network). The CCPS generates a maximum output voltage of 50 kV at average current of 2.4 A with 4 units of the CCPS. The modulator peak output capacity is 400 kV, 500 A and 7.5 us at a pulse repetition rate of 60 pps using CCPS, a modified type-E PFN, and a pulse transformer. In this paper, the test results of the modulator system will be described.
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MOP047	The BINP HLS to Measure Vertical Changes on PAL-XFEL Buildings and Ground	133
	H. J. Choi, K.H. Gil, H.-S. Kang, S.H. Kim, K.W. Seo PAL, Pohang, Kyungbuk, Republic of Korea
	PAL-XFEL is being installed and will be completed by December of 2015 so that users can be supported beginning in 2016. PAL-XFEL equipment should continuously maintain the bunch beam parameter. To this end, PAL-XFEL equipment has to be kept precisely aligned. As a part of the process for installing PAL-XFEL, a surface geodetic network and the installation of a tunnel measurement network inside buildings is in preparation; additionally, the fiducialization of major equipment is underway. After PAL-XFEL equipment is optimized and aligned, if the ground and buildings go through vertical changes during operation, misalignment of equipments will cause errors in the electron beam trajectory, which will lead to changes to the beam parameter. For continuous and systemic measurement of vertical changes in buildings and to monitor ground subsidence (sinks) and uplift, the BINP Ultrasonic-type Hydrostatic Levelling System (HLS) is to be installed and operated in all sections of PAL-XFEL for linear accelerator, undulator and beam line. This study will introduce the operation principle, design concept and advantages (self-calibration) of BINP ULS Sensor, and will outline its installation plan and operation plan.
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MOP049	Design, Development and Test of the Magnets for PAL-XFEL	139
	H.S. Suh, M.-H. Cho, S.-H. Jeong, Y.-G. Jung, H.-S. Kang, D.E. Kim, I.S. Ko, H.-G. Lee, S.B. Lee, B.G. Oh, K.-H. Park PAL, Pohang, Kyungbuk, Republic of Korea
	PAL-XFEL is now being constructed with the goal of 0.1 nm hard X-ray in Pohang, Korea. As the first phase we will construct 10 GeV linac, one hard X-ray and one soft X-ray beamlines which require 6 different families of 55 dipole magnets, 11 families of 209 quadrupole magnets, and 3 families of 48 corrector magnets. We have designed these magnets with considering the efficient production and the proper power supplies. This paper describes an outline of the design and test results of the magnets until now.
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TUP043	PAL-XFEL Cavity BPM Prototype Beam Test at ITF	468
	S.J. Lee, J.H. Han, H.-S. Kang, C. Kim, S.H. Kim, I.S. Ko, Y.J. Park, D.C. Shin PAL, Pohang, Republic of Korea
	To achieve sub-micrometer resolution, PAL-XFEL undulator section will use X-band Cavity beam position monitor (BPM) systems. The prototype cavity BPM pick-up was designed and fabricated to test the performance of the cavity BPM system. The fabricated prototype cavity BPM pick-up was installed at Pohang Accelerator Laboratory injector test facility (PAL ITF) for the beam test. Under 200 pC beam charge condition, the signal properties of the cavity BPM pick-up were measured. Also, the dynamic range of the cavity BPM pick-up was measured by using the corrector magnet. In this paper, the design and beam test results of the prototype cavity BPM pick-up will be discussed.
	Poster TUP043 [0.695 MB]
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TUP055	Technical Overview of Bunch Compressor System for PAL XFEL	490
	H.-G. Lee, Y.-G. Jung, H.-S. Kang, D.E. Kim, K.W. Kim, S.B. Lee, D.H. Na, B.G. Oh, K.-H. Park, H.S. Suh, Y.J. Suh PAL, Pohang, Republic of Korea
	Pohang Accelerator Laboratory(PAL) is developing a SASE X-ray Free Electron Laser based on 10 GeV linear accelerator. Bunch compressor (BC) systems are developed to be used for the linear accelerator tunnel. It consists of three(BC1, BC2, BC3_H) hard X-ray line and one(BC3_S) soft X-ray line. BC systems are composed of four dipole magnets, three quadrupole magnet, BPM and collimator. The support system is based on an asymmetric four-dipole magnet chicane in which asymmetry and variable R56. can be optimized. This flexibility is achieved by allowing the middle two dipole magnets to move transversely. In this paper, we describe the design of the stages used for precise movement of the bunch compressor magnets and associated diagnostics components.
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WEA01	Current Status of PAL-XFEL Facility
	H.-S. Lee, H.-S. Kang, K.W. Kim, I.S. Ko PAL, Pohang, Kyungbuk, Republic of Korea I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea
	Funding: The authors would like to gratefully acknowledge support by MSICTFP. PAL-XFEL facility is an 1110 meters long laboratory for generating X-ray free electron laser. The radiation ranges between 0.1 and 10 nm. The facility consisted of three halls, a 780 m S-band linac hall for 10 GeV, a 225 m undulator hall for hard X-ray and a 10⁵ m hard X-ray beam-line hall for user experiments. A soft X-ray undulator and a soft X-ray beam-line hall which have the length of 110 and 100 meters respectively are built in the facility. The building construction was completed in February 17, 2015. The installation of devices had been started accordingly.
	Slides WEA01 [6.167 MB]
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WEP037	Development Activites Related to RF Cables for Good Phase Stability	654
	J. Hu, H.-S. Kang, H.-S. Lee PAL, Pohang, Kyungbuk, Republic of Korea
	XFEL systems reqiure extreme RF stabilities in amplitude and phase. RF cables as parts of the systems also require very high stabilites. RF cable measurement is performed to choose good cables. Simple measurement method and test results are presented. To enhance the phase stability of RF cables a prototype jacket surrounding a RF cable is constructed and the test result is described. Finally, a modification for phase measurement of RF cables is presented.
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WEP060	Longitudinal Electron Bunch Shaping Experiments at the PAL-ITF	694
	M. Chung, J.M. Seok UNIST, Ulsan, Republic of Korea J.H. Han, J.H. Hong, H.-S. Kang, C.H. Kim PAL, Pohang, Kyungbuk, Republic of Korea J.C.T. Thangaraj Fermilab, Batavia, Illinois, USA
	Longitudinal shaping of electron beam has received much attention recently, due to its potential applications to THz generation, dielectric wakefield acceleration, improvement of FEL performance, and controlled space-charge modulation. Using a set of alpha-BBO crystals, shaping of laser pulse and electron bunch on the order of ps is tested at the Injector Test Facility (ITF) of Pohang Accelerator Laboratory (PAL). In particular, we investigate the response of the longitudinally-modulated beam to a dechirper, which is a vacuum chamber of two corrugated, metallic plates. Initial experimental results will be presented with analytical theory and numerical simulations.
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WED04	Status Report of PAL-XFEL Undulator Program	769
	D.E. Kim, M.-H. Cho, Y.-G. Jung, H.-S. Kang, I.S. Ko, H.-G. Lee, S.B. Lee, W.W. Lee, B.G. Oh, K.-H. Park, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea S. Karabekyan, J. Pflüger XFEL. EU, Hamburg, Germany
	PAL-XFEL is a SASE based FEL using S-band linear accelerator, photo cathode RF Gun, and hybrid undulator system for final lazing. The undulator system is based on EU-XFEL undulator design with necessary modifications. The changes include new magnetic geometry reflecting changed magnetic requirements, and EPICs based control system. The undulator system is in measurement and tuning stage targeting to finish installation within 2015. In this report, the development, tuning, measurement efforts for PAL-XFEL undulator system will be reported.
	Slides WED04 [3.317 MB]
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Paper

Title

Page

Status of the Fabrication of PAL-XFEL Magnet Power Supplies

66

S.-H. Jeong, Y.-G. Jung, H.-S. Kang, D.E. Kim, I.S. Ko, H.-G. Lee, S.B. Lee, B.G. Oh, K.-H. Park, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea

PAL-XFEL has been constructing including a 10 GeV linac, hard X-ray and soft X-ray branches. PAL-XFEL required for about six hundreds of magnet power supply (MPS). The eight different prototypes of MPS are developing to confirm the performance, functions, size, heat load and so on. This paper describes the test results of the prototype MPS in major specifications. All MPSs have to be installed the end of September in 2015. The installation progress of the MPS was also described.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP029

PAL XFEL Pulse Modulator System Test Results Using a High Precision CCPS

89

S.H. Kim, H.-S. Kang, G.H. Kim, I.S. Ko, S.J. Kwon, H.-S. Lee, S.S. Park, Y.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea
M.-H. Cho
POSTECH, Pohang, Kyungbuk, Republic of Korea
K.Y. Jang, H.S. Shin
POSCO ICT, Gyeonggi-do, Republic of Korea
D.S. Kim, S.Y. Lee, M. Seo
Dawonsys, Siheung-City, Republic of Korea

PAL XFEL is supposed to install 51 units of the pulse modulator power supplies for a 10-GeV linear accelerator using S-band (2856 MHz) cavities. The requirements of the modulator stability really become very tight. The stability on beam voltage is required to be less than 50 ppm. In order to obtain the high precision stability from the modulator system, we have newly produced a capacitor charging power supply (CCPS) and obtained the target stability with 10 ppm (STD) accuracy from measuring PFN (Pulse Forming Network). The CCPS generates a maximum output voltage of 50 kV at average current of 2.4 A with 4 units of the CCPS. The modulator peak output capacity is 400 kV, 500 A and 7.5 us at a pulse repetition rate of 60 pps using CCPS, a modified type-E PFN, and a pulse transformer. In this paper, the test results of the modulator system will be described.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP047

The BINP HLS to Measure Vertical Changes on PAL-XFEL Buildings and Ground

133

H. J. Choi, K.H. Gil, H.-S. Kang, S.H. Kim, K.W. Seo
PAL, Pohang, Kyungbuk, Republic of Korea

PAL-XFEL is being installed and will be completed by December of 2015 so that users can be supported beginning in 2016. PAL-XFEL equipment should continuously maintain the bunch beam parameter. To this end, PAL-XFEL equipment has to be kept precisely aligned. As a part of the process for installing PAL-XFEL, a surface geodetic network and the installation of a tunnel measurement network inside buildings is in preparation; additionally, the fiducialization of major equipment is underway. After PAL-XFEL equipment is optimized and aligned, if the ground and buildings go through vertical changes during operation, misalignment of equipments will cause errors in the electron beam trajectory, which will lead to changes to the beam parameter. For continuous and systemic measurement of vertical changes in buildings and to monitor ground subsidence (sinks) and uplift, the BINP Ultrasonic-type Hydrostatic Levelling System (HLS) is to be installed and operated in all sections of PAL-XFEL for linear accelerator, undulator and beam line. This study will introduce the operation principle, design concept and advantages (self-calibration) of BINP ULS Sensor, and will outline its installation plan and operation plan.

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP049

Design, Development and Test of the Magnets for PAL-XFEL

139

H.S. Suh, M.-H. Cho, S.-H. Jeong, Y.-G. Jung, H.-S. Kang, D.E. Kim, I.S. Ko, H.-G. Lee, S.B. Lee, B.G. Oh, K.-H. Park
PAL, Pohang, Kyungbuk, Republic of Korea

PAL-XFEL is now being constructed with the goal of 0.1 nm hard X-ray in Pohang, Korea. As the first phase we will construct 10 GeV linac, one hard X-ray and one soft X-ray beamlines which require 6 different families of 55 dipole magnets, 11 families of 209 quadrupole magnets, and 3 families of 48 corrector magnets. We have designed these magnets with considering the efficient production and the proper power supplies. This paper describes an outline of the design and test results of the magnets until now.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUP043

PAL-XFEL Cavity BPM Prototype Beam Test at ITF

468

S.J. Lee, J.H. Han, H.-S. Kang, C. Kim, S.H. Kim, I.S. Ko, Y.J. Park, D.C. Shin
PAL, Pohang, Republic of Korea

To achieve sub-micrometer resolution, PAL-XFEL undulator section will use X-band Cavity beam position monitor (BPM) systems. The prototype cavity BPM pick-up was designed and fabricated to test the performance of the cavity BPM system. The fabricated prototype cavity BPM pick-up was installed at Pohang Accelerator Laboratory injector test facility (PAL ITF) for the beam test. Under 200 pC beam charge condition, the signal properties of the cavity BPM pick-up were measured. Also, the dynamic range of the cavity BPM pick-up was measured by using the corrector magnet. In this paper, the design and beam test results of the prototype cavity BPM pick-up will be discussed.

Poster TUP043 [0.695 MB]

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TUP055

Technical Overview of Bunch Compressor System for PAL XFEL

490

H.-G. Lee, Y.-G. Jung, H.-S. Kang, D.E. Kim, K.W. Kim, S.B. Lee, D.H. Na, B.G. Oh, K.-H. Park, H.S. Suh, Y.J. Suh
PAL, Pohang, Republic of Korea

Pohang Accelerator Laboratory(PAL) is developing a SASE X-ray Free Electron Laser based on 10 GeV linear accelerator. Bunch compressor (BC) systems are developed to be used for the linear accelerator tunnel. It consists of three(BC1, BC2, BC3_H) hard X-ray line and one(BC3_S) soft X-ray line. BC systems are composed of four dipole magnets, three quadrupole magnet, BPM and collimator. The support system is based on an asymmetric four-dipole magnet chicane in which asymmetry and variable R56. can be optimized. This flexibility is achieved by allowing the middle two dipole magnets to move transversely. In this paper, we describe the design of the stages used for precise movement of the bunch compressor magnets and associated diagnostics components.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEA01

Current Status of PAL-XFEL Facility

H.-S. Lee, H.-S. Kang, K.W. Kim, I.S. Ko
PAL, Pohang, Kyungbuk, Republic of Korea
I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea

Funding: The authors would like to gratefully acknowledge support by MSICTFP.
PAL-XFEL facility is an 1110 meters long laboratory for generating X-ray free electron laser. The radiation ranges between 0.1 and 10 nm. The facility consisted of three halls, a 780 m S-band linac hall for 10 GeV, a 225 m undulator hall for hard X-ray and a 10⁵ m hard X-ray beam-line hall for user experiments. A soft X-ray undulator and a soft X-ray beam-line hall which have the length of 110 and 100 meters respectively are built in the facility. The building construction was completed in February 17, 2015. The installation of devices had been started accordingly.

Slides WEA01 [6.167 MB]

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WEP037

Development Activites Related to RF Cables for Good Phase Stability

654

J. Hu, H.-S. Kang, H.-S. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

XFEL systems reqiure extreme RF stabilities in amplitude and phase. RF cables as parts of the systems also require very high stabilites. RF cable measurement is performed to choose good cables. Simple measurement method and test results are presented. To enhance the phase stability of RF cables a prototype jacket surrounding a RF cable is constructed and the test result is described. Finally, a modification for phase measurement of RF cables is presented.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEP060

Longitudinal Electron Bunch Shaping Experiments at the PAL-ITF

694

M. Chung, J.M. Seok
UNIST, Ulsan, Republic of Korea
J.H. Han, J.H. Hong, H.-S. Kang, C.H. Kim
PAL, Pohang, Kyungbuk, Republic of Korea
J.C.T. Thangaraj
Fermilab, Batavia, Illinois, USA

Longitudinal shaping of electron beam has received much attention recently, due to its potential applications to THz generation, dielectric wakefield acceleration, improvement of FEL performance, and controlled space-charge modulation. Using a set of alpha-BBO crystals, shaping of laser pulse and electron bunch on the order of ps is tested at the Injector Test Facility (ITF) of Pohang Accelerator Laboratory (PAL). In particular, we investigate the response of the longitudinally-modulated beam to a dechirper, which is a vacuum chamber of two corrugated, metallic plates. Initial experimental results will be presented with analytical theory and numerical simulations.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WED04

Status Report of PAL-XFEL Undulator Program

769

D.E. Kim, M.-H. Cho, Y.-G. Jung, H.-S. Kang, I.S. Ko, H.-G. Lee, S.B. Lee, W.W. Lee, B.G. Oh, K.-H. Park, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea
S. Karabekyan, J. Pflüger
XFEL. EU, Hamburg, Germany

PAL-XFEL is a SASE based FEL using S-band linear accelerator, photo cathode RF Gun, and hybrid undulator system for final lazing. The undulator system is based on EU-XFEL undulator design with necessary modifications. The changes include new magnetic geometry reflecting changed magnetic requirements, and EPICs based control system. The undulator system is in measurement and tuning stage targeting to finish installation within 2015. In this report, the development, tuning, measurement efforts for PAL-XFEL undulator system will be reported.

Slides WED04 [3.317 MB]

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