IPAC2012 - List of Authors (Wang, D.)

Paper

Title

Page

On the Single Bunch Longitudinal Collective Effects in BEPCII

3054

D. Wang, Z. Duan, J. Gao, Y. Li, L. Wang, L. Wang, N. Wang
IHEP, Beijing, People's Republic of China

Funding: National Natural Science Foundation of China,project 11175192.
In order to study the single bunch longitudinal instability in BEPCII, experiments on the bunch lengthening phenomenon were made. By analyzing the experimental data based on the Gao’s theory, the longitudinal loss factor for the bunch are obtained. Also, the total wake potential and the inductance of the machine are estimated.

TUPPP056

Study of the Energy Chirp Effects on Seeded FEL Schemes at SDUV-FEL

1724

C. Feng, D. Wang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

Seeded free-electron laser (FEL) schemes hold great promise for generation of high brilliant radiation with a narrow bandwidth. Analysis with the idealized electron beam with constant current and energy indicate that both the high-gain harmonic generation (HGHG) and the echo-enabled harmonic generation (EEHG) can produce Fourier-transform limited radiation pulses. However, residual energy variations due to nonlinearity of the accelerator or energy modulations due to microbunching instability will be unavoidable and may broaden the bandwidth of the seeded FEL. In this paper, we study the energy chirp effects on both the HGHG and EEHG schemes. Analytic and simulation calculations are presented and compared with the experimental data. Results show that the coherence properties of the EEHG FEL may not be degraded by the energy chirp when properly choosing the parameters of the dispersion sections.

TUPPP057

Design of a Wavelength Continuously Tunable Ultraviolet Coherent Light Source

1727

T. Zhang, D. Wang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China
X.M. Yang
DICP, Dalian, People's Republic of China

Funding: Work supported by National Natural Science Foundation of China (Grant No. 11075199)
Dalian Coherent Light Source (DCL) is a proposed FEL-based novel light source user facility, will be located in Dalian city, China. DCL will mainly servers on the field of molecular reaction dynamics, ultra-fast physical chemistry experiments, etc. Running on the High-Gain-Harmonic-Generation (HGHG) FEL mode, DCL is expected to cover the FEL wavelength from 50 nm to 150 nm, with the help of continuously tuning Optical Parametric Amplification (OPA) seed laser system, which wavelength can be varied between 240 nm and 360 nm. Numerical simulation shows that the FEL pulse energy of DCL can surpass 100 μJ, at the whole full range wavelength with the undulator tapering technology, and the photon number can be up to 10¹³ per pulse, which is sufficient for user experiments.

WEOBB01

Measurement of the Local Energy Spread of Electron Beam at SDUV-FEL

2143

C. Feng, J.H. Chen, H.X. Deng, T. Lan, B. Liu, D. Wang, X. Wang, M. Zhang, T. Zhang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

The slice energy spread of electron beam is a very important parameter for high gain free electron lasers (FELs) especially the seeded FELs. Because of its extremely small value, highly accurate measurement of the slice energy spread is rather challenging. In this paper, we propose a novel method to accurately measure the slice energy spread based on the coherent harmonic generation (CHG) scheme. This method has been demonstrated on the Shanghai deep ultraviolent FEL (SDUV-FEL), and the results show that the slice energy spread is about only 1.2keV at the exit of the 136MeV linac when the bunch compressor is off, and this value change to about 2.6keV when the bunch compressor is on.
* Chao Feng, et al, Phys. Rev. ST Accel. Beams 14, 090701 (2011)

Slides WEOBB01 [3.309 MB]

THPPC014

Commissioning Status of the 3 MeV RFQ for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University

3305

Q.Z. Xing, Y.J. Bai, D.T. Bin, J.C. Cai, C. Cheng, L. Du, Q. Du, C. Jiang, Q. Qiang, D. Wang, X.W. Wang, Z.F. Xiong, S.Y. Yang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
J.H. Billen
TechSource, Santa Fe, New Mexico, USA
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
X.L. Guan
Tsinghua University, Beijing, People's Republic of China
J. Stovall
CERN, Geneva, Switzerland
L.M. Young
AES, Medford, NY, USA

Funding: Work supported by the “985 Project” of the Ministry of Education of China.
We present, in this paper, the commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. In 2012 the 3-meter-long RFQ will deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. Braze of the vanes was completed in September, 2011. The final field tuning of the whole cavity was completed in October, 2011. Initial commissioning will be underway at the beginning of 2012.

Paper	Title	Page
WEPPR057	On the Single Bunch Longitudinal Collective Effects in BEPCII	3054
	D. Wang, Z. Duan, J. Gao, Y. Li, L. Wang, L. Wang, N. Wang IHEP, Beijing, People's Republic of China
	Funding: National Natural Science Foundation of China,project 11175192. In order to study the single bunch longitudinal instability in BEPCII, experiments on the bunch lengthening phenomenon were made. By analyzing the experimental data based on the Gao’s theory, the longitudinal loss factor for the bunch are obtained. Also, the total wake potential and the inductance of the machine are estimated.

TUPPP056	Study of the Energy Chirp Effects on Seeded FEL Schemes at SDUV-FEL	1724
	C. Feng, D. Wang, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	Seeded free-electron laser (FEL) schemes hold great promise for generation of high brilliant radiation with a narrow bandwidth. Analysis with the idealized electron beam with constant current and energy indicate that both the high-gain harmonic generation (HGHG) and the echo-enabled harmonic generation (EEHG) can produce Fourier-transform limited radiation pulses. However, residual energy variations due to nonlinearity of the accelerator or energy modulations due to microbunching instability will be unavoidable and may broaden the bandwidth of the seeded FEL. In this paper, we study the energy chirp effects on both the HGHG and EEHG schemes. Analytic and simulation calculations are presented and compared with the experimental data. Results show that the coherence properties of the EEHG FEL may not be degraded by the energy chirp when properly choosing the parameters of the dispersion sections.

TUPPP057	Design of a Wavelength Continuously Tunable Ultraviolet Coherent Light Source	1727
	T. Zhang, D. Wang, Z.T. Zhao SINAP, Shanghai, People's Republic of China X.M. Yang DICP, Dalian, People's Republic of China
	Funding: Work supported by National Natural Science Foundation of China (Grant No. 11075199) Dalian Coherent Light Source (DCL) is a proposed FEL-based novel light source user facility, will be located in Dalian city, China. DCL will mainly servers on the field of molecular reaction dynamics, ultra-fast physical chemistry experiments, etc. Running on the High-Gain-Harmonic-Generation (HGHG) FEL mode, DCL is expected to cover the FEL wavelength from 50 nm to 150 nm, with the help of continuously tuning Optical Parametric Amplification (OPA) seed laser system, which wavelength can be varied between 240 nm and 360 nm. Numerical simulation shows that the FEL pulse energy of DCL can surpass 100 μJ, at the whole full range wavelength with the undulator tapering technology, and the photon number can be up to 10¹³ per pulse, which is sufficient for user experiments.

WEOBB01	Measurement of the Local Energy Spread of Electron Beam at SDUV-FEL	2143
	C. Feng, J.H. Chen, H.X. Deng, T. Lan, B. Liu, D. Wang, X. Wang, M. Zhang, T. Zhang, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	The slice energy spread of electron beam is a very important parameter for high gain free electron lasers (FELs) especially the seeded FELs. Because of its extremely small value, highly accurate measurement of the slice energy spread is rather challenging. In this paper, we propose a novel method to accurately measure the slice energy spread based on the coherent harmonic generation (CHG) scheme. This method has been demonstrated on the Shanghai deep ultraviolent FEL (SDUV-FEL), and the results show that the slice energy spread is about only 1.2keV at the exit of the 136MeV linac when the bunch compressor is off, and this value change to about 2.6keV when the bunch compressor is on. * Chao Feng, et al, Phys. Rev. ST Accel. Beams 14, 090701 (2011)
	Slides WEOBB01 [3.309 MB]

THPPC014	Commissioning Status of the 3 MeV RFQ for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University	3305
	Q.Z. Xing, Y.J. Bai, D.T. Bin, J.C. Cai, C. Cheng, L. Du, Q. Du, C. Jiang, Q. Qiang, D. Wang, X.W. Wang, Z.F. Xiong, S.Y. Yang, H.Y. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China J.H. Billen TechSource, Santa Fe, New Mexico, USA W.Q. Guan, Y. He, J. Li NUCTECH, Beijing, People's Republic of China X.L. Guan Tsinghua University, Beijing, People's Republic of China J. Stovall CERN, Geneva, Switzerland L.M. Young AES, Medford, NY, USA
	Funding: Work supported by the “985 Project” of the Ministry of Education of China. We present, in this paper, the commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. In 2012 the 3-meter-long RFQ will deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. Braze of the vanes was completed in September, 2011. The final field tuning of the whole cavity was completed in October, 2011. Initial commissioning will be underway at the beginning of 2012.