FEL2015 - List of Authors (Ko, I.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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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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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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WEP058	Emittance Measurements at the PAL-XFEL Injector Test Facility	690
	J. Lee POSTECH, Pohang, Kyungbuk, Republic of Korea J.H. Han, J.H. Hong, C.H. Kim, I.S. Ko, S.J. Lee, S.J. Park, H. Yang PAL, Pohang, Kyungbuk, Republic of Korea
	The PAL-XFEL Injector Test Facility (ITF) at PAL has been operating for experimental optimization of electron beam parameters and for beam test of various accelerator components. It consists of a photocathode RF gun, two S-band accelerating structures, a laser heater system, and beam diagnostics such as ICTs, BPMs, screens, beam energy spectrometers and an RF deflector. Projected and slice emittance measurements were carried out by using single quadrupole scan. In this paper, we present the emittance measurements.
	Poster WEP058 [0.646 MB]
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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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MOP048	The Design of Low Noise Magnet Power Supply	136
	K.-H. Park, S.-H. Jeong, Y.-G. Jung, D.E. Kim, H.-G. Lee, S.B. Lee, B.G. Oh, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea W.S. Choi, I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea
	The accelerator needs a high stable magnet power supply(MPS) with low noise output. The stability requirements of the some MPSs in accelerator were in the range of the ~10 ppm. There are many noise sources which affect the stability of MPS. Thus the design of the MPS requests much attention on the noise reduction scheme from the beginning stage. The noise on the MPS divided into some sources such as the ripple voltage coming from rectifier for the DC link, switching noise at the FET or IGBT on the high voltage, noise coming digital logics around DSP and its peripheral circuits, ground matters on the analogue signal process and so on. This paper analyzed the noise sources and described the way how to build the low noise power supply.
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MOP082	New Soft X-Ray Undulator Line Using 10 GeV Electron Beam in PAL-XFEL	237
	C.H. Shim, I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea Y.W. Parc PAL, Pohang, Kyungbuk, Republic of Korea
	PAL-XFEL is designed to have five undulator lines and only two undulator lines, the HXR undulator line with 10 GeV electron beam and the SXR undulator line with 3.15 GeV electron beam, will be installed during phase I. A photon beam energy from 0.28 to 1.24 keV will be provided at the SXR undulator line and different range from 2 to 20 keV will be supplied at the HXR undulator line. According to existing schedule, however, photon beam energy from 1.24 to 2 keV won't be provided in PAL-XFEL. In this research, new soft X-ray undulator line for PAL-XFEL using 10 GeV electron beam in main linac is proposed to cover the vacant photon energy. Four candidates are evaluated by estimating and comparing FEL performances using Ming Xie's formula.
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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)

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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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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WEP058

Emittance Measurements at the PAL-XFEL Injector Test Facility

690

J. Lee
POSTECH, Pohang, Kyungbuk, Republic of Korea
J.H. Han, J.H. Hong, C.H. Kim, I.S. Ko, S.J. Lee, S.J. Park, H. Yang
PAL, Pohang, Kyungbuk, Republic of Korea

The PAL-XFEL Injector Test Facility (ITF) at PAL has been operating for experimental optimization of electron beam parameters and for beam test of various accelerator components. It consists of a photocathode RF gun, two S-band accelerating structures, a laser heater system, and beam diagnostics such as ICTs, BPMs, screens, beam energy spectrometers and an RF deflector. Projected and slice emittance measurements were carried out by using single quadrupole scan. In this paper, we present the emittance measurements.

Poster WEP058 [0.646 MB]

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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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MOP048

The Design of Low Noise Magnet Power Supply

136

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

The accelerator needs a high stable magnet power supply(MPS) with low noise output. The stability requirements of the some MPSs in accelerator were in the range of the ~10 ppm. There are many noise sources which affect the stability of MPS. Thus the design of the MPS requests much attention on the noise reduction scheme from the beginning stage. The noise on the MPS divided into some sources such as the ripple voltage coming from rectifier for the DC link, switching noise at the FET or IGBT on the high voltage, noise coming digital logics around DSP and its peripheral circuits, ground matters on the analogue signal process and so on. This paper analyzed the noise sources and described the way how to build the low noise power supply.

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

MOP082

New Soft X-Ray Undulator Line Using 10 GeV Electron Beam in PAL-XFEL

237

C.H. Shim, I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea
Y.W. Parc
PAL, Pohang, Kyungbuk, Republic of Korea

PAL-XFEL is designed to have five undulator lines and only two undulator lines, the HXR undulator line with 10 GeV electron beam and the SXR undulator line with 3.15 GeV electron beam, will be installed during phase I. A photon beam energy from 0.28 to 1.24 keV will be provided at the SXR undulator line and different range from 2 to 20 keV will be supplied at the HXR undulator line. According to existing schedule, however, photon beam energy from 1.24 to 2 keV won't be provided in PAL-XFEL. In this research, new soft X-ray undulator line for PAL-XFEL using 10 GeV electron beam in main linac is proposed to cover the vacant photon energy. Four candidates are evaluated by estimating and comparing FEL performances using Ming Xie's formula.

Export •

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