| Paper |
Title |
Page |
| MOPC013 |
Effect of Jitter and Quadrupole Alignment Errors on SASE FEL Performance
|
94 |
| |
- V. G. Khachatryan, A. Tarloyan, V. M. Tsakanov
CANDLE, Yerevan
- W. Decking
DESY, Hamburg
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Numerical simulations of the radiation process at the European XFEL project are presented. The impact of quadrupole misalignments on the saturation length and saturation power is investigated using the simulation codes SIMPLEX and GENESIS. The influence of trajectory steering in the presence of BPM misalignments on the FEL performance is analyzed. The study is performed for the SASE 1 undulator designed for 0.1nm radiation wavelength.
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| MOPC014 |
Optimization of the Focusing Lattice for European XFEL
|
97 |
| |
- V. G. Khachatryan, A. Tarloyan, V. M. Tsakanov
CANDLE, Yerevan
- W. Decking
DESY, Hamburg
- V. V. Sahakyan
YSU, Yerevan
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| |
Detailed knowledge of the impact of the undulator section focusing lattice on the FEL performance is an important issue to ensure the stable operation of the facility with reliable tolerances. In this paper the results of numerical simulation studies for the European XFEL project are presented. The saturation length, saturation power and the spectral brightness of the SASE FEL are calculated for various focusing lattice arrangements. A focusing optics option with reduced number of FODO cells is discussed to reach the design goals with relaxed quadrupole magnet tolerances. The numerical simulations are performed using the SIMPLEX and GENESIS codes.
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| MOPC019 |
Velocity Bunching at FLASH
|
112 |
| |
- T. Limberg, B. Beutner, W. Decking, M. Huening, M. Krasilnikov, M. Vogt
DESY, Hamburg
- O. Grimm
Uni HH, Hamburg
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| |
The vacuum-ultra-violet free electron laser in Hamburg (FLASH) is a linac driven SASE-FEL. High peak currents are, in routine operation, produced using magnetic bunch compression chicanes. Longitudinal dispersion in these chicanes allow bunch length changes of relativistic electron beams. For low energy electron beams (~5 MeV), the velocity dependence on electron energy can be utilized for bunch compression. Since strong bunch compression at low beam energies gives rise to strong space charge interactions which has an impact on, for instance, beam emittance and is therefore not suitable for full compression to the kA peak currents needed for SASE operation. Moderate velocity bunching, however, might be used to optimize the total bunch compression system of FLASH or the European XFEL. Experiments on the velocity bunching process at FLASH are presented here. Results on bunch length and transverse emittance measurements are discussed and compared with numerical tracking calculations.
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| TUPP018 |
Impact of Electromagnetic Fields in TESLA RF Modules on Transverse Beam Dynamics
|
1568 |
| |
- E. Prat, W. Decking, M. Dohlus, T. Limberg, I. Zagorodnov
DESY, Hamburg
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| |
Transverse electric fields in TESLA rf modules exist on one hand because of deformations of the longitudinal accelerating field in the presence of rf structure misalignments or in the vicinity of asymmetrically machine parts like input couplers. On the other hand, the beam itself induces transverse wake fields if it does not travel through the center of a perfectly rotationally symmetric structure. Transverse deflecting fields deflect beam particles. The average deflection causes a change in the beam trajectory; the phase dependence of the transverse field leads to a variation of the transverse kick along the longitudinal position of the bunch and thus in general to a change in projected emittance. If the strength of the transverse field component varies along the transverse direction itself, slice emittance will be also affected. We will present the amplitudes and spatial variations of transverse fields generated by the mechanisms described above, and discuss their impact on beam trajectories and shape.
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| WEPC073 |
Layout of the Beam Switchyard at the European XFEL
|
2163 |
| |
- W. Decking, F. Obier
DESY, Hamburg
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| |
A unique feature of the European XFEL will be the possibility to distribute electron bunches of one beam pulse to different FEL beam lines. This is achieved by using a combination of fast kickers and a DC septum. Integration of a beam abortion dump allows a flexible selection of the bunch pattern at the FEL experiment, while the superconducting linear accelerator operates with constant beam-loading. We describe the principal scheme, the geometrical and optical layout and deal with stability and technical issues like the fast kicker development.
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| THPC055 |
Dynamic Aperture Studies for PETRA III Including Magnet Imperfections
|
3107 |
| |
- A. Kling, K. Balewski, W. Decking
DESY, Hamburg
- Y. J. Li
BNL, Upton, New York
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| |
PETRA III is a 3rd generation synchrotron radiation light source. Efficient injection in the top up mode requires a dynamic aperture of 30 mmmrad or larger, while a 2 hour Touschek lifetime needs an average momentum aperture of around 1.5 %. We present studies on the impact of recently measured magnet imperfections on the available dynamic aperture. To this end, tracking simulations have been performed including the effects of measured multipole errors of lattice magnets and of 20 four-meters-long damping wigglers.
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