IPAC2012 - List of Authors (Kang, H.-S.)

Paper	Title	Page
MOPPD018	A FFAG Design Study for an Accelerator-driven System	403
	T.-Y. Lee, H.-S. Kang, H.-S. Lee PAL, Pohang, Kyungbuk, Republic of Korea
	Design of a 1 GeV FFAG accelerator is studied for the accelerator-driven sub-critical nuclear reactor system. Scaling and non-scaling lattices are studied and compared with each other. Corresponding magnet design and RF system are considered.

TUPPC027	Multi Objective Genetic Optimization for Linac Lattice of PAL XFEL	1224
	C.H. Yi, M.-H. Cho, S.H. Kim, W. Namkung POSTECH, Pohang, Kyungbuk, Republic of Korea H.-S. Kang PAL, Pohang, Kyungbuk, Republic of Korea K.-J. Kim ANL, Argonne, USA
	Funding: Work supported by MEST and POSTECH Physics BK21 Program. There are a large number of variables and objectives in design of XFEL linac lattices. Recently, most of accelerator physics field, are applying the multi-objective genetic algorithm (MOGA) for these kinds of problems. MOGA was applied to the PAL XFEL linac lattice design. Longitudinal position of all components was fixed before applying MOGA. RF parameters of RF cavities and bending angles of bunch compressors are selected as variables. Various beam parameters computed by ELEGANT were used as objectives. By using MOGA, new linac lattice designs with 2 and 3 bunch compressors was generated and their beam properties are presented in this paper.

TUPPD061	High-Power RF Test of an RF-Gun for PAL-XFEL	1539
	J.H. Hong, J.H. Han, H.-S. Kang, C. Kim, S.H. Kim, C.-K. Min, S.S. Park, S.J. Park, Y.J. Park PAL, Pohang, Kyungbuk, Republic of Korea M.S. Chae, I.S. Ko, Y.W. Parc POSTECH, Pohang, Kyungbuk, Republic of Korea
	A photocathode RF-gun for the X-ray free electron laser (XFEL) at the Pohang Accelerator Laboratory (PAL) has been fabricated and tested at PAL. This RF-gun is based on a 1.6-cell cavity with dual-feed waveguide ports and two pumping ports. The RF gun was designed by PAL and POSTECH. The RF-gun has been successfully tested with a cathode electric field gradient up to 126MV/m at a repetition rate of 30 Hz. This paper reports the recent results on the beam test of the RF-gun with high power RF at the gun test facility. We present and discuss the measurements of the basic beam parameters such as charge, energy, energy spread, and transverse emittance.

TUPPP060	Injector Design for PAL-XFEL Project	1732
	J.H. Han, M.S. Chae, J.H. Hong, I. Hwang, H.-S. Kang, I.S. Ko, S.J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: The Ministry of Education, Science and Technology of the Korean Government The PAL-XFEL project has the baseline specification of FEL radiation down to 0.1 nm with a 10 GeV S-band normal conducting linac. To fulfill the requirement of the beam parameter, the S-band photoinjector was designed. Numerical optimizations for nominal and low charge operations are presented.

TUPPP061	Status of the PAL-XFEL Project	1735
	J.H. Han, H.-S. Kang, I.S. Ko PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: The Ministry of Education, Science and Technology of the Korean Government PAL-XFEL is designed to generate X-ray radiation in the range of 0.1 and 10 nm for users. The machine consists of a 10 GeV linear accelerator and five undulator beamlines. Electron beams are generated at a low emittance S-band photocathode RF gun and accelerated with an S-band normal conducting linac. Three hard X-ray beamlines will be located at the end of the linac. Electron beams for two soft X-ray beamlines will be switched at a medium energy. The project started in 2011 and the building construction is ongoing. Resent progress of the project and an update of the current progress are presented.

TUPPP062	Start to End Simulation of Three Bunch Compressor Lattice for PAL XFEL	1738
	H.-S. Kang, M.-H. Cho, J.H. Han, T.-H. Kang, I.S. Ko PAL, Pohang, Kyungbuk, Republic of Korea C.H. Yi POSTECH, Pohang, Kyungbuk, Republic of Korea
	The PAL XFEL is a 0.1-nm hard X-ray FEL project starting from 2011 to finish in 2014, which aims at achieving higher photon flux than 10¹² photons/pulse at 0.1 nm using a 10 GeV electron linac. The PAL XFEL is designed to have a hard x-ray undulator line at the end of linac and a branch line at 2.65 GeV point for soft X-ray undulator line. The three bunch compressor lattice (3-BC) is chosen to minimize emitance growth due to CSR and minimize correlated energy spread. The 3-BC lattice makes it possible to operate soft X-ray FEL undulator line simultaneously and independently from hard X-ray FEL undulator line.

WEPPC023	Status and Progress of RF System for the PLS-II Storage Ring	2254
	M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, C.D. Park, H.J. Park, I.S. Park, Y.U. Sohn, I.H. Yu PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: Supported by the Korea Ministry of Science and Technology The RF system for the Pohang Light Source (PLS) storage ring was upgraded for PLS-II project of 3.0GeV/400mA from 2.5GeV/200mA. the RF system is commissioning with five normal conducting(NC) RF cavities at total maximum RF power of 280kW to the cavities with two 300kW klystron and two 75kW klystron amplifiers in 2011. The super conducting(SC) cavities will be installed on August 2012 because of long delivery. Therefore three NC RF cavities will be replaced with two SC cavities with cryomodules, and operated with cryogenics, digital low level, and 300kW klystron high power system. Also we are preparing the third SC cavity stand to increase the storage ring current up to 400mA with all insertion devices operation. This paper describes the present installation, commissioning, operation status, upgrade progress, and future plan of the RF system for the upgraded project of PLS-II storage ring.

WEPPC024	Preliminary Test of Superconducting RF Cavities for PLS-II	2257
	Y.U. Sohn, M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Nam, C.D. Park, H.J. Park, I.S. Park, I.H. Yu PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: This project is supported by the Korea Ministry of Science and Technology. The main part of the Installation for the PLS-II upgrade was finished in June and is on the way to user operation through elaborate commissioning. Up to now, the achievement is 150 mA beam current at 3 GeV with multi-bunch mode with 5 normal conducting cavities which served in the PLS before. After installation of 2 SRF cavities in the summer of 2012, the PLS-II will have 300 mA beam current with 20 IDs by 2 superconducting RF cavities until July, 2014. Finally, one more superconducting cavity will be added in August, 2014, and beam current will rise to 400 mA. The two SRF cavities are under test and conditioning. The two main subsystems, SRF cavities and ceramic windows were tested independently to confirm their performance. Each cavity recorded its accelerating voltage as 3.27 MV and 3.24 MV at 4.2K, respectively. Two RF windows also passed their specification, 300 kW CW traveling wave and 150 kW CW standing wave. The preliminary tests of SRF cryomodules are reported in the presentation.

THPPC057	S-band High Power RF System for 10 GeV PAL-XFEL	3419
	W.H. Hwang, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Kim, H.-S. Lee, Y.J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 120 Hz. In high power operation, it is important to decrease the rf electric field to protect rf break-down in high power rf components. To obtain the maximum beam, we must reduce the phase difference between waveguide branches including accelerating structure and minimize the environment influences. This paper describes the waveguide system and high power rf components for the PxFEL.

THPPC058	S-band Low-level RF System for 10 GeV PAL-XFEL	3422
	W.H. Hwang, J.Y. Huang, H.-S. Kang, H.-S. Lee, W.W. Lee PAL, Pohang, Kyungbuk, Republic of Korea
	In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 120 Hz. And the specifications of the rf phase and amplitude stability are 0.05 degrees(rms) and 0.01%(rms) respectively. We achieved the stability of 0.03 degrees(p-p) at low power rf output using a phase amplitude detection system(PAD) and phase amplitude control(PAC) system. This paper describes the microwave system and the PAD and PAC system for the PxFEL.

Paper

Title

Page

A FFAG Design Study for an Accelerator-driven System

403

T.-Y. Lee, H.-S. Kang, H.-S. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

Design of a 1 GeV FFAG accelerator is studied for the accelerator-driven sub-critical nuclear reactor system. Scaling and non-scaling lattices are studied and compared with each other. Corresponding magnet design and RF system are considered.

TUPPC027

Multi Objective Genetic Optimization for Linac Lattice of PAL XFEL

1224

C.H. Yi, M.-H. Cho, S.H. Kim, W. Namkung
POSTECH, Pohang, Kyungbuk, Republic of Korea
H.-S. Kang
PAL, Pohang, Kyungbuk, Republic of Korea
K.-J. Kim
ANL, Argonne, USA

Funding: Work supported by MEST and POSTECH Physics BK21 Program.
There are a large number of variables and objectives in design of XFEL linac lattices. Recently, most of accelerator physics field, are applying the multi-objective genetic algorithm (MOGA) for these kinds of problems. MOGA was applied to the PAL XFEL linac lattice design. Longitudinal position of all components was fixed before applying MOGA. RF parameters of RF cavities and bending angles of bunch compressors are selected as variables. Various beam parameters computed by ELEGANT were used as objectives. By using MOGA, new linac lattice designs with 2 and 3 bunch compressors was generated and their beam properties are presented in this paper.

TUPPD061

High-Power RF Test of an RF-Gun for PAL-XFEL

1539

J.H. Hong, J.H. Han, H.-S. Kang, C. Kim, S.H. Kim, C.-K. Min, S.S. Park, S.J. Park, Y.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea
M.S. Chae, I.S. Ko, Y.W. Parc
POSTECH, Pohang, Kyungbuk, Republic of Korea

A photocathode RF-gun for the X-ray free electron laser (XFEL) at the Pohang Accelerator Laboratory (PAL) has been fabricated and tested at PAL. This RF-gun is based on a 1.6-cell cavity with dual-feed waveguide ports and two pumping ports. The RF gun was designed by PAL and POSTECH. The RF-gun has been successfully tested with a cathode electric field gradient up to 126MV/m at a repetition rate of 30 Hz. This paper reports the recent results on the beam test of the RF-gun with high power RF at the gun test facility. We present and discuss the measurements of the basic beam parameters such as charge, energy, energy spread, and transverse emittance.

TUPPP060

Injector Design for PAL-XFEL Project

1732

J.H. Han, M.S. Chae, J.H. Hong, I. Hwang, H.-S. Kang, I.S. Ko, S.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: The Ministry of Education, Science and Technology of the Korean Government
The PAL-XFEL project has the baseline specification of FEL radiation down to 0.1 nm with a 10 GeV S-band normal conducting linac. To fulfill the requirement of the beam parameter, the S-band photoinjector was designed. Numerical optimizations for nominal and low charge operations are presented.

TUPPP061

Status of the PAL-XFEL Project

1735

J.H. Han, H.-S. Kang, I.S. Ko
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: The Ministry of Education, Science and Technology of the Korean Government
PAL-XFEL is designed to generate X-ray radiation in the range of 0.1 and 10 nm for users. The machine consists of a 10 GeV linear accelerator and five undulator beamlines. Electron beams are generated at a low emittance S-band photocathode RF gun and accelerated with an S-band normal conducting linac. Three hard X-ray beamlines will be located at the end of the linac. Electron beams for two soft X-ray beamlines will be switched at a medium energy. The project started in 2011 and the building construction is ongoing. Resent progress of the project and an update of the current progress are presented.

TUPPP062

Start to End Simulation of Three Bunch Compressor Lattice for PAL XFEL

1738

H.-S. Kang, M.-H. Cho, J.H. Han, T.-H. Kang, I.S. Ko
PAL, Pohang, Kyungbuk, Republic of Korea
C.H. Yi
POSTECH, Pohang, Kyungbuk, Republic of Korea

The PAL XFEL is a 0.1-nm hard X-ray FEL project starting from 2011 to finish in 2014, which aims at achieving higher photon flux than 10¹² photons/pulse at 0.1 nm using a 10 GeV electron linac. The PAL XFEL is designed to have a hard x-ray undulator line at the end of linac and a branch line at 2.65 GeV point for soft X-ray undulator line. The three bunch compressor lattice (3-BC) is chosen to minimize emitance growth due to CSR and minimize correlated energy spread. The 3-BC lattice makes it possible to operate soft X-ray FEL undulator line simultaneously and independently from hard X-ray FEL undulator line.

WEPPC023

Status and Progress of RF System for the PLS-II Storage Ring

2254

M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, C.D. Park, H.J. Park, I.S. Park, Y.U. Sohn, I.H. Yu
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: Supported by the Korea Ministry of Science and Technology
The RF system for the Pohang Light Source (PLS) storage ring was upgraded for PLS-II project of 3.0GeV/400mA from 2.5GeV/200mA. the RF system is commissioning with five normal conducting(NC) RF cavities at total maximum RF power of 280kW to the cavities with two 300kW klystron and two 75kW klystron amplifiers in 2011. The super conducting(SC) cavities will be installed on August 2012 because of long delivery. Therefore three NC RF cavities will be replaced with two SC cavities with cryomodules, and operated with cryogenics, digital low level, and 300kW klystron high power system. Also we are preparing the third SC cavity stand to increase the storage ring current up to 400mA with all insertion devices operation. This paper describes the present installation, commissioning, operation status, upgrade progress, and future plan of the RF system for the upgraded project of PLS-II storage ring.

WEPPC024

Preliminary Test of Superconducting RF Cavities for PLS-II

2257

Y.U. Sohn, M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Nam, C.D. Park, H.J. Park, I.S. Park, I.H. Yu
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This project is supported by the Korea Ministry of Science and Technology.
The main part of the Installation for the PLS-II upgrade was finished in June and is on the way to user operation through elaborate commissioning. Up to now, the achievement is 150 mA beam current at 3 GeV with multi-bunch mode with 5 normal conducting cavities which served in the PLS before. After installation of 2 SRF cavities in the summer of 2012, the PLS-II will have 300 mA beam current with 20 IDs by 2 superconducting RF cavities until July, 2014. Finally, one more superconducting cavity will be added in August, 2014, and beam current will rise to 400 mA. The two SRF cavities are under test and conditioning. The two main subsystems, SRF cavities and ceramic windows were tested independently to confirm their performance. Each cavity recorded its accelerating voltage as 3.27 MV and 3.24 MV at 4.2K, respectively. Two RF windows also passed their specification, 300 kW CW traveling wave and 150 kW CW standing wave. The preliminary tests of SRF cryomodules are reported in the presentation.

THPPC057

S-band High Power RF System for 10 GeV PAL-XFEL

3419

W.H. Hwang, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Kim, H.-S. Lee, Y.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 120 Hz. In high power operation, it is important to decrease the rf electric field to protect rf break-down in high power rf components. To obtain the maximum beam, we must reduce the phase difference between waveguide branches including accelerating structure and minimize the environment influences. This paper describes the waveguide system and high power rf components for the PxFEL.

THPPC058

S-band Low-level RF System for 10 GeV PAL-XFEL

3422

W.H. Hwang, J.Y. Huang, H.-S. Kang, H.-S. Lee, W.W. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 120 Hz. And the specifications of the rf phase and amplitude stability are 0.05 degrees(rms) and 0.01%(rms) respectively. We achieved the stability of 0.03 degrees(p-p) at low power rf output using a phase amplitude detection system(PAD) and phase amplitude control(PAC) system. This paper describes the microwave system and the PAD and PAC system for the PxFEL.