| Paper |
Title |
Page |
| MOPPH036 |
First Experiences with the FIR-FEL at ELBE
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97 |
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- P. Michel, W. Seidel, G. Staats, J. Teichert, R. Wuensch, U. Lehnert
FZD, Dresden
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We show the design and the parameters of operation of the long-wavelength (U100) FEL of ELBE. First lasing has been shown in August, 2006. Since then, the laser has undergone thorough commissioning and is available for user experiments since fall, 2006. Besides in-house users the IR beam is available to external users in the FELBE (FEL@ELBE) program witch is a part of the integrated activity on synchrotron and free electron laser science in the EU. At the beginning of 2007 lasing in the full designed wavelength range from 20μm to 200μm was demonstrated. The laser power typically reaches several W in CW operation but drops for very long wavelengths depending on the size of the used outcoupling hole. However, there exists a serious problem with small gaps in the providable wavelength spectrum. We attribute this behaviour to the transmission characteristics of the overmoded partial waveguide used from the undulator entrance to the first mirror.
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| MOPPH072 |
The IR-Beam Transport System from the ELBE-FELs to the User Labs
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171 |
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- M. Justus, K.-W. Leege, D. Proehl, R. Schlenk, A. Winter, D. Wohlfarth, R. Wuensch, W. Seidel
FZD, Dresden
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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 (4-200 microns). The IR light is transported to several laboratories in the same building and to the adjacent building of the High Magnetic Field Laboratory (HLD) as well. The latter is up to 70m away from the FELs. Constructional peculiarities, the large wavelength range (a factor of 50 between the shortest and the longest wavelengths), 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, plane and toroidal gold-covered copper mirrors, exit windows, and diagnostic elements. The designed transport system produces a beam waist at selected spots in each laboratory representing an image of the outcoupling hole. Spot size and position are independent of the wavelength. In the HLD the beam is fed into a circulare waveguide, guiding the radiation to the sample inside of a cryostat. To ensure the desired beam properties, the transport system has been analyzed by means of various ray and wave optical models.
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