Parameter of echo-enabled harmonic generation free electron lasers

The echo-enabled harmonic generation free electron laser (EEHG FEL) was proposed for producing short wavelength FEL radiation recently. The parameter sensitivity of EEHG FEL is studied through numerical simulation as the main method and analytical calculation. The simulation results are in excellent agreement with the analytical calculation results. The energy spread growth and emittance growth due to the coherent synchrotron radiation (CSR) in dispersing section are estimated and simulation is also done. The results show that the energy spread growth and emittance growth are small and can be ignored.