On harmonic operation of Shanghai deep UV free electron laser

By choosing parameters in the modulator, the dispersive section and the seed laser, the spatial bunching of the electron beam can be correlated to the n-th harmonic of the radiator radiation, instead of the fundamental radiation in conventional high-gain harmonic generation (HGHG). Thus, the radiator undulator is operated at high harmonic mode. In this paper, the possibility of harmonic operation of Shanghai deep ultraviolet (SDUV) free electron laser (FEL) is studied. Discussions on the principle of harmonic operation, the simulation code development, the simulation results, and the proposed experimental procedure for verification of harmonic operation at the SDUV FEL are also presented.