IPAC2012 - List of Authors (Feng, C.)

Paper

Title

Page

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.

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]

Paper	Title	Page
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.

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]