A proposed method to characterize high harmonic microbunching in EEHG operation of SDUV-FEL
- Received Date: 2009-09-11
- Accepted Date: 2010-03-30
- Available Online: 2010-10-05
Abstract:
The echo-enabled harmonic generation (EEHG) scheme offers remarkable efficiency for generating high harmonic microbunching with a relatively small energy modulation. A proof of principle experiment of the EEHG scheme has been proposed at the Shanghai deep ultraviolet (SDUV) free electron laser (FEL) facility, where the 4th harmonic of the seed laser is amplified in the 9~m long radiator. To explore the advantages of the EEHG scheme, in this paper, a method of measuring the coherent high harmonic radiation of the radiator is proposed to investigate the electron beam microbunching corresponding to the 10th—20th harmonics of the seed laser. The principle of the proposed method, comparisons with existing methods and the simulation results are presented and discussed.