Search Results (3 total)

We report the first experimental results on a high-gain harmonic-generation (HGHG) free-electron laser (FEL) operating in the ultraviolet. An 800 nm seed from a Ti:sapphire laser has been used to produce saturated amplified radiation at the 266 nm third harmonic. The results confirm the predictions for HGHG FEL operation: stable central wavelength, narrow bandwidth, and small pulse-energy fluctuation.

We present an experimental evidence of a bunch compression scheme that uses a traveling wave accelerating structure as a compressor. The bunch length issued from a laser-driven radio-frequency electron source was compressed by a factor >3 using an S-band traveling wave structure located immediately downstream from the electron source. Experimental data are found to be in good agreement with particle tracking simulations.

The nature of off-axis undulator radiation is discussed. Of particular interest is coherent off-axis radiation, where the wavelengths of emission are longer than the electron bunch length. We show how this off-axis radiation may be used to measure relative electron bunch lengths. The theory is presented, and calculated spectra are presented in a number of cases of interest.