Nonlinear Energy Chirp Compensation with Corrugated Structures

Herein, a feasible method is proposed to compensate the high-order effect during bunch length compression, thereby enhancing the peak current of a high-repetition-rate X-ray free-electron laser source. In the proposed method, the corrugated structure is inserted downstream of the high-order harmonic cavities to function as a passive linearizer and enhance the longitudinal profile of the electron beam. Three-dimensional simulations are performed to analyze the evolution of the longitudinal phase space, and the results demonstrate that the profile of the electron beam is improved and the peak current can be easily optimized to over 2 kA with a bunch charge of 100 pC.