First SASE and seeded FEL lasing of the NSLS DUV FEL at 266 and 400 nm

The Deep Ultra-Violet Free Electron Laser (DUVFEL) at the National Synchrotron Light Source consists of a 5MeV photoinjector, a 200MeV S-band linear accelerator, a four-magnet chicane compressor and a 10m wiggler with a 3.9 cm period. The commissioning of the SDL accelerator was completed recently and it is routinely producing a highquality electron beam with a peak current of B400A and a normalised emittance of 3–4mmmrad. The first SASE lasing of the DUV FEL has been demonstrated at both 266 and 400 nm. The gain length of the SASE experiments was measured to be 66 cm in both cases and up to 20 nJ per pulse was obtained. A laser seeded FEL at 266 nm is in the very early stages of commissioning and amplification of the laser seed has been observed. The goal of the seeded laser FEL is to saturate the FEL and thereby generate sufficient third harmonic at 89 nm for experimental applications. Here we report the observation and measurements of SASE at 400 and 266 nm and the first results of seeded FEL. r 2003 Elsevier Science B.V. All rights reserved.