Author/Authors :
Biedron، نويسنده , , S.G. and Dejus، نويسنده , , R.J and Huang، نويسنده , , Z. and Milton، نويسنده , , S.V. and Sajaev، نويسنده , , V. and Berg، نويسنده , , W. and Borland، نويسنده , , M. and Den Hartog، نويسنده , , P.K. and Erdmann، نويسنده , , M. and Fawley، نويسنده , , W.M. and Freund، نويسنده , , H.P. and Gluskin، نويسنده , , E. and Kim، نويسنده , , K.–J. and Lewellen، نويسنده , , J.W. and Li، نويسنده , , Y. and Lumpkin، نويسنده , , A.H. and Moog، نويسنده , , E.R. and Nassiri، نويسنده , , A. and Wiemerslage، نويسنده , , G. and Yang، نويسنده , , B.X.، نويسنده ,
Abstract :
SASE saturation was recently achieved at the Advanced Photon Sourceʹs SASE FEL in the low-energy undulator test line at 530 nm and 385 nm. The electron beam microbunching becomes more and more prominent until saturation is achieved. This bunching causes nonlinear harmonic emission that extends the usefulness of a SASE system in achieving shorter FEL wavelengths for the same electron beam energy. We have investigated the intensity of the fundamental and second harmonic undulator radiation as a function of distance along the undulator line and present the experimental results and compare them to numerical simulations. In addition, we have measured the single-shot second harmonic spectra as well as the simultaneous fundamental and second harmonic spectra and present the experimental results.
Keywords :
Free-electron lasers , Intense particle beams and radiation sources , harmonic generation , Frequency conversion
