| Paper |
Title |
Page |
| MOPPH032 |
Three Dimensional Simulations on Harmonic Operation of Shanghai Deep Ultraviolet Free Electron Laser
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55 |
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- H. X. Deng, Z. M. Dai
SINAP, Shanghai
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With the right choice of the parameters in high gain harmonic generation (HGHG), the electron beam may be spatially bunched on the high harmonic of the radiator resonant frequency, instead of the fundamental frequency in the normal HGHG. Thus, the radiator is operated at harmonic mode and the harmonic power is expected to be significantly enhanced. Recently, the possibility of a proof-of-principle harmonic operation experiment based on Shanghai deep ultraviolet (SDUV) free electron laser (FEL) test facility has been studied. In this paper, the principle of harmonic operation, the numerical simulation approaches, and the detailed performances of harmonic operation of SDUV FEL are presented.
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| MOPPH033 |
Study of Short Seed Pulse Effects in High Gain Harmonic Generation Free Electron Laser
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59 |
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- H. X. Deng, Z. M. Dai
SINAP, Shanghai
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To generate the hard x-ray free electron laser (FEL), multi-stage high gain harmonic generation (HGHG) will employ seed pulse with longitudinal length down to tens of femtoseconds. Thus, strong slippage effects and broad bandwidth effects are introduced. In this paper, we study the short seed pulse effects of HGHG. A set of multi-frequency equations is derived to appropriately model the interaction between the seed laser and the electrons in the modulator. The short seed pulse effects on the electron beam’s energy modulation, the output wavelength tuning, the output pulse length and the output peak power in HGHG are theoretically and numerically investigated. It shows that the short seed pulse significantly influences HGHG performances, and the influences should be taken into accounts in the design of seeded FEL scheme.
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