| Paper | Title | Page |
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| TUPPH015 | Remote Controlled IR-Diagnostic Station for the FEL at Rossendorf | 341 |
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The remote controlled diagnostic station delivers a small amount of the IR radiation by means of a system of relocatable mirrors and beam splitters to the spectrometer and to various power detectors working in different power ranges. Furthermore, a long wavelength MCT detector is integrated in the diagnostic station for gain and loss measurement in the whole wavelength range of the U27-FEL. The average radiation power available for the users can be reduced by a remote controlled attenuator. To characterize the optical micropulse duration we have built a non-collinear background-free autocorrelator as a part of the diagnostic station. By using a CdTe single-crystal for second-harmonic generation a broad wavelength coverage is obtained. Certain experiments require high pulse energies but moderate or low average power. For such experiments the repetition rate of the Rossendorf FEL can be reduced from 13 MHz to 1 kHz, in the future also to 1 Hz, by a semiconductor plasma switch excited with a synchronized Nd:YAG amplifier. This system is under commissioning and we will report on first results*.
*Submitted as a poster to the FEL 2006 conference. |
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| TUPPH016 | The Partial-Waveguide Resonator of the U100-FEL at FZ Rossendorf | 345 |
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| The U100-FEL, which is under construction at the Forschungszentrum Rossendorf, will be equipped with a parallel-plate waveguide which is 10 mm high (inside), almost 8 m long and covers more than two third of the total resonator length. Its horizontal width varies from 70 mm within the undulator up to 130 mm at the downstream resonator mirror. A special diagnostics had to be developed to align the electron and the IR beam within this waveguide. A drive system has been designed for the cylindrical downstream resonator mirror. It allows to shift and tilt the mirror, which is completely embedded in the waveguide. The size and the curvature of the bifocal upstream resonator mirror has been fitted to minimize the optical loss in the resonator. To adjust the outcoupling to the varying beam size on the mirror surface a set of three collocated, relocatable mirrors with different outcoupling hole sizes will be applied. We present various sophisticated design concepts which comply with the large wavelength range and the special requirements caused by the bulky waveguide construction and its small free space in vertical direction. |