IPAC2012 - List of Authors (Kim, K.-J.)

Paper	Title	Page
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.

WEPPC042	Low Impedance Bellows for High-current Beam Operations	2303
	G. Wu, K.-J. Kim, A. Nassiri, G.J. Waldschmidt, Y. Yang ANL, Argonne, USA J.J. Feingold, J.D. Mammosser, R.A. Rimmer, H. Wang JLAB, Newport News, Virginia, USA J. Jang, S.H. Kim POSTECH, Pohang, Kyungbuk, Republic of Korea
	Funding: Work Supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357 In particle accelerators, bellows are commonly used to connect beamline components. Such bellows are traditionally shielded to lower the beam impedance. Excessive beam impedance can cause overheating in the bellows, especially in high beam current operation. For an SRF-based accelerator, the bellows must also be particulate free. Many designs of shielded bellows incorporate rf slides or fingers that prevent convolutions from being exposed to wakefields. Unfortunately these mechanical structures tend to generate particulates that, if left in the SRF accelerator, can migrate into superconducting cavities, the accelerator's critical components. In this paper, we describe a prototype unshielded bellows that has low beam impedance and no risk of particulate generation.

Paper

Title

Page

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.

WEPPC042

Low Impedance Bellows for High-current Beam Operations

2303

G. Wu, K.-J. Kim, A. Nassiri, G.J. Waldschmidt, Y. Yang
ANL, Argonne, USA
J.J. Feingold, J.D. Mammosser, R.A. Rimmer, H. Wang
JLAB, Newport News, Virginia, USA
J. Jang, S.H. Kim
POSTECH, Pohang, Kyungbuk, Republic of Korea

Funding: Work Supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357
In particle accelerators, bellows are commonly used to connect beamline components. Such bellows are traditionally shielded to lower the beam impedance. Excessive beam impedance can cause overheating in the bellows, especially in high beam current operation. For an SRF-based accelerator, the bellows must also be particulate free. Many designs of shielded bellows incorporate rf slides or fingers that prevent convolutions from being exposed to wakefields. Unfortunately these mechanical structures tend to generate particulates that, if left in the SRF accelerator, can migrate into superconducting cavities, the accelerator's critical components. In this paper, we describe a prototype unshielded bellows that has low beam impedance and no risk of particulate generation.