Two-stage EEHG for coherent hard X-ray generation based on a superconducting linac

摘要

A two-stage echo-enabled harmonic generation(EEHG)scheme is proposed for a superconducting linacdriven FEL to produce coherent hard X-rays.Electron beams of quite different bunch lengths are separately used in each stage of EEHG,and a monochromator is designed to purify the radiation from the first stage for seeding the second stage.Theoretical analysis and 3D simulations indicate that the proposed scheme can generate high-repetition-rate coherent hard X-ray pulses directly from a conventional UV seed laser.