Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2010, Vol. 21 ›› Issue (1): 1-6 doi: 10.13538/j.1001-8042/nst.21.1-6


Modified model for harmonic generation free electron laser

DENG Haixiao* DAI Zhimin   

  1. Shanghai Institute of Applied Physics, Shanghai 201800, China
DENG Haixiao, DAI Zhimin. Modified model for harmonic generation free electron laser.Nuclear Science and Techniques, 2010, 21(1): 1-6     doi: 10.13538/j.1001-8042/nst.21.1-6


The longitudinal modulation to the electron beam by a coherent seed laser pulse is widely used for generating fully coherent, short wavelength radiation in various harmonic generation free electron laser (FEL) schemes. After introducing the density modulation, microstructures down to attosecond scale are produced over the distance of one seed laser wavelength. In order to take into account the microstructures in the theoretical and numerical analysis, in the frame of undulator period averaged approach, a modified model for harmonic generation FEL is developed in this paper. With the modified model, three harmonic generation FEL examples are investigated by employing Shanghai soft X-ray FEL (SXFEL) parameters. In FEL schemes with ultra-high harmonic generation and ultra-short pulse, the modified model presents some interesting aspects which are helpful for understanding of radiation pulse evolution, bunching efficiency and noise propagation issues.

Key words: FEL, Harmonic, Model, Attosecond