sFLASH - FIRST RESULTS OF DIRECT SEEDING AT FLASH ∗

The free-electron laser facility FLASH at DESY (Hamburg) was upgraded during afive month shutdown in winter 2009 [1]. Part of this upgrade was the installation of a direct seeding experiment in the XUV spectral range. Beside all components for transport and diagnostics of the photon beam in and out of the accelerator environment, a new 10 m long variable gap undulator was installed upstream of the existing FLASH undulator system. The seed pulses are generated within a noble gas jet by focusing 40 fs long Ti:Sa laser pulses into it resulting a comb of higher harmonics. In the first phase of the experiment the 21st harmonic of the 800 nm drive laser will be used to seed the FEL process. The commissioning of the experiment has started in April and thefirst results are expected after the FLASH commissioning period mid of summer 2010. The experimental setup and the commissioning procedures as well as first result will be presented.