Chirped pulse amplification in a free-electron laser amplifier

Linear chirped pulse amplification at single pass free-electron laser (FEL) amplifier is studied through numerical simulations using our 1D time-dependent code GOFEL-P. The processes of chirped pulses with different chirped parameters being amplified by the FEL amplifier or the FEL amplifier with energy-chirped electron beam are studied. The peak power and width of the final compressed pulse with different chirped parameters have been calculated. The results show that, the FEL amplifier can amplify the chirped pulse, the peak power in the final compressed pulse can reach 10 s GW and the width of the pulse can be 10 s fs with the parameters of TTF. In the case of using the energy-chirped electron beam to amplify chirped pulse, the gain bandwidth of the FEL amplifier will be wider and the chirped parameter will be larger more. The peak power in the final compressed pulse can even reach near 10 times larger and the width of the pulse 10 times shorter than that without electron-beam energy chirped.