High-Gain Harmonic-Generation Experiment

(WE-1-01) Presenting Author: A. Doyuran

A. Doyuran, M. Babzien, T. Shaftan, L.-H. Yu, I. Ben-Zvi, L.F. DiMauro, W. Graves, E. Johnson, S. Krinsky, R. Malone, I. Pogorelsky, J. Skaritka, G.Rakowsky, L. Solomon, X.J. Wang, M. Woodle, J. Wu, V. Yakimenko (BNL); S.G. Biedron, J.N. Galayda, E. Gluskin, J. Jagger, V. Sajaev, I. Vasserman (APS)  

Brookhaven National Laboratory, Upton, New York 11973; Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439

We report on the experimental investigation of high-gain harmonic-generation carried out at the Accelerator Test Facility at Brookhaven National Laboratory. A seed CO₂ laser at a wavelength of 10.5 mm was used to generate FEL output at the second-harmonic wavelength of 5.25 mm. The duration of the output pulse was measured using a second-harmonic intensity autocorrelator. The relationship between the pulse length and the measured output spectrum is discussed. In addition, we report on the measurement of the energy distribution of the electron beam after it exits the second undulator. The observed behavior is consistent with what is expected at saturation. Finally, we report the measurement of second and third harmonics at 2.62 mm and 1.75 mm.