| Paper | Title | Page |
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| TUPMN013 | Dynamic Multipole Shimming of the APPLE Undulator UE112 | 941 |
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| The dynamic off axis field integrals of the BESSY UE112 are of the order of 3 Tmm. They reduce the dynamic aperture significantly which is not tolerable for top-up operation. The dynamic multipoles have successfully been shimmed for the elliptical mode using distributed Fe-shims. In the inclined mode the multipoles are minimized actively with rotatable permanent magnets which are adjusted dependent on gap and phase position. The dynamic properties of the unshimmed and the shimmed device have been simulated using an analytic model for the field description and a generating function algorithm for tracking. | ||
| TUPMN017 | ''Jitter Free'' FEL Pulses for Pump and Probe Experiments | 953 |
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Funding: Bundesministerium fur Bildung und Forschung and the Land Berlin The cascaded High Gain Harmonic Generation (HGHG) scheme proposed for the BESSY-FEL contains an inherent potential for providing jitter free radiation pulses for pump and probe experiments. In an HGHG stage an energy modulation is imprinted to the electron beam by a seeding radiation. A dispersive section converts this energy modulation to a spatial modulation which is optimized for a particular harmonic. The subsequent radiator is optimized for this harmonics and generates radiation with high power which is used as seeding radiation for the next stage. After passage through the modulator, the seeding radiation become redundant and can be separated from the prebunched electrons using a deflecting dispersive chicane. This radiation and the final FEL output will have a fixed temporal separation as the first one is the driving seeding radiation for the second one. Using the planned test facility for HGHG scheme at BESSY as an example, we present simulation studies for a sequences of two jitter free pump and probe pulses including the deflecting chicane and a suitable beam line. |
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| TUPMN012 | STARS - A Two-Stage High-Gain Harmonic Generation FEL Demonstrator | 938 |
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Funding: Bundesministerium fur Bildung und Forschung and the Land Berlin BESSY is proposing a demonstration facility, called STARS, for a two-stage high-gain harmonic generation free electron laser (HGHG FEL). STARS is planned for lasing in the wavelength range 40 to 70 nm, requiring a beam energy of 325 MeV. The facility consists of a normal conducting gun, three superconducting TESLA-type acceleration modules modified for CW operation, a single stage bunch compressor and finally a two-stage HGHG cascaded FEL. This paper describes the faciliy layout and the rationale behind the operation parameters. |
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| TUPMN015 | First Commissioning Results of the Metrology Light Source | 947 |
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Funding: Physikalisch-Technische Bundesanstalt, Abbestr. 2 - 12, 10587 Berlin, Germany The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, has built an electron storage ring in close cooperation with BESSY for energies between 200 MeV and 600 MeV. This storage ring, named Metrology Light Source (MLS), will mainly be used for radiometry and can be operated as a primary source standard. The spectral range of the MLS is optimized for UV, EUV and also for Terahertz radiation. Commissioning is planed for May 2007. First MLS commissioning results will be reported. |