Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

In the Forschungszentrum Dresden-Rossendorf, two free-electron lasers (FELs) have been put into operation. They produce laser light in the medium and the far infrared wavelength range (4-150 ìm). The IR ligh is transported to several laboratories in the same building and to the adjacent building of the High Magnetic Field Laboratory as well, where the experimental setups are up to 70maway from the FELs. Constructional peculiarities, the large wavelength range, the high average power in cw regime, and the beam property requirements of the users pose a challenge to the beam line design. The transport system includes vacuum pipes, diagnostic elements, plane and toroidal gold-covered copper mirrors, and exit windows. The designed transport system produces a beam waist at selected spots in each laboratory representing a magnified image of the outcoupling hole. Spot size and position are independent of the wavelength.