IPAC2012 - List of Authors (Namkung, W.)

Paper	Title	Page
THPPC016	PLSII Linac RF Conditioning Status	3311
	H.-S. Lee, J.Y. Huang, W.H. Hwang, H.-G. Kim, K.R. Kim, S.H. Kim, S.H. Kim, S.H. Nam, W. Namkung, S.S. Park, S.J. Park, Y.J. Park, S. Shin PAL, Pohang, Kyungbuk, Republic of Korea
	PLS linac has been upgraded in energy from 2.5 to 3.0 GeV. A klystron supplies RF power of 80 MW four acceleration structures through a SLED. But our machine is not enough RF power to get 3 GeV beam energy. So we have changed the RF scheme in four modules as a klystron supplies RF power of 80 MW two accelerating structures through a SLED. There were several problems during the RF conditioning and beam operation. So we will describe the conditioning results and the current status in this paper.

TUPPC026	Design of Compact C-Band Standing-Wave Accelerating Structure Enhancing RF Phase Focusing	1221
	H.R. Yang, M.-H. Cho, J. Jang, S.H. Kim, W. Namkung, S.J. Park POSTECH, Pohang, Kyungbuk, Republic of Korea J.-S. Oh NFRI, Daejon, Republic of Korea
	Funding: Work supported by POSTECH Physics BK21 Program. We design a C-band standing-wave accelerating structure for an X-ray source of the imaging and medical applications. It is capable of producing 6-MeV, 100-mA pulsed electron beams which is focused by less than 1.5 mm without external magnets. As an RF source, we use peak 1.5-MW magnetron with duty factor of 0.08%. The accelerating structure is a bi-periodic and on-axis-coupled structure with a built-in bunching section, which consists 3 bunching cells, 13 normal cells and a coupler cell. It operated with π/2-mode standing-waves. The bunching section is designed to enhance the RF phase focusing in order to achieve 1.2-mm beam spot size. Each cavity is designed with the MWS code to maximize the effective shunt impedance within 3.5% inter-cell coupling. In this paper, we present design details of RF cavities and the beam dynamics simulation by the PARMELA code.

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.

Paper

Title

Page

PLSII Linac RF Conditioning Status

3311

H.-S. Lee, J.Y. Huang, W.H. Hwang, H.-G. Kim, K.R. Kim, S.H. Kim, S.H. Kim, S.H. Nam, W. Namkung, S.S. Park, S.J. Park, Y.J. Park, S. Shin
PAL, Pohang, Kyungbuk, Republic of Korea

PLS linac has been upgraded in energy from 2.5 to 3.0 GeV. A klystron supplies RF power of 80 MW four acceleration structures through a SLED. But our machine is not enough RF power to get 3 GeV beam energy. So we have changed the RF scheme in four modules as a klystron supplies RF power of 80 MW two accelerating structures through a SLED. There were several problems during the RF conditioning and beam operation. So we will describe the conditioning results and the current status in this paper.

TUPPC026

Design of Compact C-Band Standing-Wave Accelerating Structure Enhancing RF Phase Focusing

1221

H.R. Yang, M.-H. Cho, J. Jang, S.H. Kim, W. Namkung, S.J. Park
POSTECH, Pohang, Kyungbuk, Republic of Korea
J.-S. Oh
NFRI, Daejon, Republic of Korea

Funding: Work supported by POSTECH Physics BK21 Program.
We design a C-band standing-wave accelerating structure for an X-ray source of the imaging and medical applications. It is capable of producing 6-MeV, 100-mA pulsed electron beams which is focused by less than 1.5 mm without external magnets. As an RF source, we use peak 1.5-MW magnetron with duty factor of 0.08%. The accelerating structure is a bi-periodic and on-axis-coupled structure with a built-in bunching section, which consists 3 bunching cells, 13 normal cells and a coupler cell. It operated with π/2-mode standing-waves. The bunching section is designed to enhance the RF phase focusing in order to achieve 1.2-mm beam spot size. Each cavity is designed with the MWS code to maximize the effective shunt impedance within 3.5% inter-cell coupling. In this paper, we present design details of RF cavities and the beam dynamics simulation by the PARMELA code.

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.