DESY, Hamburg
The free-electron laser user facility FLASH at DESY, Germany is world-wide the only SASE-FEL operating in the VUV and the soft X-ray wavelengths range. Since summer 2005, FLASH operates as a user facility providing almost fully coherent, 10 femtosecond long laser radiation in the wavelength range from 47 nm to 6.5 nm with an unprecedented brilliance - many orders of magnitude higher than conventional facilities. The SASE radiation contains also higher harmonics. Several experiments have successfully used the third and fifth harmonics, in the latter case down to a wavelength of 1.59 nm. Starting autumn 2009, FLASH will be upgraded with an additional superconducting TESLA type accelerating module boosting its beam energy to 1.2 GeV. This will allow lasing below 5 nm. In addition, a 3rd harmonic accelerating module will be installed, which improves the longitudinal phase space and the overall performance of the facility.
Uni HH, Hamburg
DESY, Hamburg
PSI, Villigen
DELTA, Dortmund
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin
The Free-electron-laser at Hamburg (FLASH) operates in the Self-Amplified Spontaneous Emission (SASE) mode, delivering to users photons in the XUV wavelength range. The FEL seeding schemes promise to improve the properties of the generated radiation in terms of stability in intensity and time. Such an experiment using higher harmonics of an optical laser as a seed is currently under construction at FLASH. The installation of the XUV seeding experiment (sFLASH) is going to take place in fall 2009. This includes mounting of new variable-gap undulators upstream of the existing SASE-undulators, building the XUV-seed source as well as installation of additional photon diagnostics and electron beam instrumentation. In this contribution the layout of sFLASH will be discussed together with the technical design of its major components.
Uni HH, Hamburg
DESY, Hamburg
PSI, Villigen
DELTA, Dortmund
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin
Starting from next year, the technical feasibility of a direct seeding scheme at 30 and 13nm will be studied at the free-electron laser FLASH at DESY. During a major shutdown in order to upgrade the SASE-FEL facility, it is planned to install a HHG source, a new chain of 10 m variable gap undulators and a dedicated commissioning beamline for photon diagnostics and pilot time-resolved pump-probe experiments. Besides demonstrating successful seeding at short wavelength, the project aims for time resolution in the 10 fs range to study ultrafast processes by combining the naturally synchronized FEL and seed laser pulses. After the extraction of the radiation in a magnetic chicane, a short branch will accommodate intensity and beam monitors and a spectrometer. The intensity monitor detects scattered photons from a gold mesh on a shot-to-shot basis using micro-channel plates and XUV diodes. It is designed to detect photons several orders of magnitude apart in flux, i.e. spanning the wide range from the spontaneous emission up to the seeded FEL radiation at gigawatt power level. Simulations of this device are presented as well as test and calibration measurements carried out at FLASH.