IPAC2016 - List of Authors (Zhang, W.Q.)

Paper	Title	Page
MOPOW023	Proposal of an X-band Linearizer for Dalian Coherent Light Source	766
	G.L. Wang, X.M. Yang, W.Q. Zhang DICP, Dalian, People's Republic of China H.X. Deng, C. Feng SINAP, Shanghai, People's Republic of China
	Dalian coherent Light Source (DCLS) is a FEL user facility working at 50-150 nm, now under commissioning in Dalian, China. The facility based on HGHG mode, requires high brightness electron beam with small energy spread and low emittance. To linearise the longitudinal phase space before the bunch compression, an X-band linearizer is considered before the bunch compressor. In this paper, we study the performance improvement of DCLS FEL radiation by using such a harmonic cavity, including the jitter of central wavelength induced by arriving time and a larger bunch compression ratio for femtosecond FEL application.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW023
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MOPOW024	Harmonic Lasing Options for Dalian Coherent Light Source	770
	G.L. Wang, X.M. Yang, W.Q. Zhang DICP, Dalian, People's Republic of China H.X. Deng, C. Feng SINAP, Shanghai, People's Republic of China
	Harmonic lasing of the Free Electron Laser can be achieved by disrupting the electron interaction with the usually dominant fundamental while allowing the increasing of a harmonic interaction. It's a cheap and relatively efficient way to extend the photon energy range of a particular FEL. In this paper, we discussed the possibility of harmonic lasing concept at Dalian Coherent Light Source by using the combination of tapered undulators and phase shifters. Our calculation shows that it's feasible with the present layout to provide intense, stable, and narrow-band harmonic radiation, the FEL wavelength could be down to 20 nm and the corresponding pulse energy is about 10 μJ.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW024
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THPOW009	Optimal Design of a Photocathode Electron Gun with High-brightness and High-repetition Rate Based on Genetic Algorithm	3947
	Zh. X. Tang, X.M. Yang, W.Q. Zhang DICP, Dalian, People's Republic of China Y.J. Pei, Y. Yu USTC/NSRL, Hefei, Anhui, People's Republic of China
	A low RF frequency of normal conducting photocathode gun with high-brightness and high-repetition rate is designed as an electron source of the Next Generation Light Source (NGLS). In order to optimize the performance of the gun, a genetic multi-objective algorithm has been used. A genetic algorithm is used because of the inherent complexity of the large number of parameters of the cavity geometry available for optimization. On the other hand, the multiplicity of requirements on the beam, which include beam emittance, beam pulse length, energy chirp, as well as pulse shape and peak current, leads to a multi-objective approach for the optimization technique. In this paper, we present the status of the optimization simulations, using the SUPERFISH and PERMELA particle-in-cell code.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW009
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THPOW010	Study on Characteristics of Asymmetric Centre Iris of Photocathode Microwave Electron Gun	3951
	Zh. X. Tang, X.M. Yang, W.Q. Zhang DICP, Dalian, People's Republic of China Y.J. Pei USTC/NSRL, Hefei, Anhui, People's Republic of China
	The characteristics of asymmetric iris between first cell and second cell of 1.6 cell photocathode gun are studied. For π-mode, the RF radial field of two sides of the iris is non anti-symmetric. Thus, the RF transverse force at the iris is not negligible. In this paper, we present the status of the optimization simulations, using the SUPERFISH and PARMELA particle-in-cell code. Numerical results of beam dynamics show that it can improve the emittance at the exit of the gun.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW010
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Paper

Title

Page

Proposal of an X-band Linearizer for Dalian Coherent Light Source

766

G.L. Wang, X.M. Yang, W.Q. Zhang
DICP, Dalian, People's Republic of China
H.X. Deng, C. Feng
SINAP, Shanghai, People's Republic of China

Dalian coherent Light Source (DCLS) is a FEL user facility working at 50-150 nm, now under commissioning in Dalian, China. The facility based on HGHG mode, requires high brightness electron beam with small energy spread and low emittance. To linearise the longitudinal phase space before the bunch compression, an X-band linearizer is considered before the bunch compressor. In this paper, we study the performance improvement of DCLS FEL radiation by using such a harmonic cavity, including the jitter of central wavelength induced by arriving time and a larger bunch compression ratio for femtosecond FEL application.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW023

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MOPOW024

Harmonic Lasing Options for Dalian Coherent Light Source

770

G.L. Wang, X.M. Yang, W.Q. Zhang
DICP, Dalian, People's Republic of China
H.X. Deng, C. Feng
SINAP, Shanghai, People's Republic of China

Harmonic lasing of the Free Electron Laser can be achieved by disrupting the electron interaction with the usually dominant fundamental while allowing the increasing of a harmonic interaction. It's a cheap and relatively efficient way to extend the photon energy range of a particular FEL. In this paper, we discussed the possibility of harmonic lasing concept at Dalian Coherent Light Source by using the combination of tapered undulators and phase shifters. Our calculation shows that it's feasible with the present layout to provide intense, stable, and narrow-band harmonic radiation, the FEL wavelength could be down to 20 nm and the corresponding pulse energy is about 10 μJ.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW024

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THPOW009

Optimal Design of a Photocathode Electron Gun with High-brightness and High-repetition Rate Based on Genetic Algorithm

3947

Zh. X. Tang, X.M. Yang, W.Q. Zhang
DICP, Dalian, People's Republic of China
Y.J. Pei, Y. Yu
USTC/NSRL, Hefei, Anhui, People's Republic of China

A low RF frequency of normal conducting photocathode gun with high-brightness and high-repetition rate is designed as an electron source of the Next Generation Light Source (NGLS). In order to optimize the performance of the gun, a genetic multi-objective algorithm has been used. A genetic algorithm is used because of the inherent complexity of the large number of parameters of the cavity geometry available for optimization. On the other hand, the multiplicity of requirements on the beam, which include beam emittance, beam pulse length, energy chirp, as well as pulse shape and peak current, leads to a multi-objective approach for the optimization technique. In this paper, we present the status of the optimization simulations, using the SUPERFISH and PERMELA particle-in-cell code.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW009

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THPOW010

Study on Characteristics of Asymmetric Centre Iris of Photocathode Microwave Electron Gun

3951

Zh. X. Tang, X.M. Yang, W.Q. Zhang
DICP, Dalian, People's Republic of China
Y.J. Pei
USTC/NSRL, Hefei, Anhui, People's Republic of China

The characteristics of asymmetric iris between first cell and second cell of 1.6 cell photocathode gun are studied. For π-mode, the RF radial field of two sides of the iris is non anti-symmetric. Thus, the RF transverse force at the iris is not negligible. In this paper, we present the status of the optimization simulations, using the SUPERFISH and PARMELA particle-in-cell code. Numerical results of beam dynamics show that it can improve the emittance at the exit of the gun.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW010

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)