Paper |
Title |
Page |
MOPC019 |
Velocity Bunching at FLASH
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112 |
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- 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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MOPC004 |
First Results from the Upgraded PITZ Facility
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70 |
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- J. W. Baehr, S. Lederer
DESY, Hamburg
- G. Asova
INRNE, Sofia
- C. H. Boulware, H.-J. Grabosch, M. Hänel, Ye. Ivanisenko, S. Khodyachykh, S. A. Korepanov, M. Krasilnikov, B. Petrosyan, S. Rimjaem, T. A. Scholz, R. Spesyvtsev, L. Staykov, F. Stephan
DESY Zeuthen, Zeuthen
- L. Hakobyan
YerPhI, Yerevan
- R. Richter
BESSY GmbH, Berlin
- J. Roensch
Uni HH, Hamburg
- K. Rosbach
Humboldt University Berlin, Institut für Physik, Berlin
- A. Shapovalov
MEPhI, Moscow
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During autumn and winter 2007 a general reconstruction of the PITZ facility was performed. A new spectrometer based on a dipole magnet with 180 degree deflection angle was inserted in the facility. The new spectrometer contains two screen stations for the measuring of the longitudinal phase space and the slice emittance. A new "Conditioning Test Stand" (CTS) was added to the facility. Using this CTS a new electron gun having an improved cooling system is under conditioning. A new photocathode laser system (developed by MBI) was installed and commissioned. The goal is to reach rise and fall times of the laser pulses of 2 ps. The system of laser diagnostic was upgraded. The results reached using this upgraded facility are reported. This concerns the conditioning results of the new gun. Furthermore, a gun will be characterised using the new diagnostics beamline and the new photocathode laser. Results of the commissioning and first measurements of the new diagnostics components will be reported.
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MOPC078 |
Tuning and Conditioning of a New High Gradient Gun Cavity at PITZ
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244 |
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- S. Rimjaem, G. Asova, J. W. Baehr, C. H. Boulware, H.-J. Grabosch, M. Hänel, Ye. Ivanisenko, M. Krasilnikov, S. Lederer, A. Oppelt, B. Petrosyan, T. A. Scholz, A. Shapovalov, R. Spesyvtsev, L. Staykov, F. Stephan
DESY Zeuthen, Zeuthen
- K. Floettmann, D. Reschke
DESY, Hamburg
- L. Hakobyan
YerPhI, Yerevan
- R. Richter
BESSY GmbH, Berlin
- J. Roensch
Uni HH, Hamburg
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A new 1.3 GHz photo cathode electron gun (prototype 4.2) for the Photo Injector Test facility in Zeuthen (PITZ) was tuned in February 2007. The main difference in the mechanical design compared to earlier guns is a significantly improved cooling system. This gun is also the first copper gun cavity where a particle free cleaning using dry ice technique was applied while in the previous guns the high pressure ultra pure water rinsing technique was used. The cavity has been installed in a new Conditioning Test Stand (CTS) at PITZ in autumn 2007. It has been conditioned to an accelerating gradient of 60 MV/m and more. Dark current measurements have been performed to monitor the improvement of conditioning and to compare with the results from the previous guns. In this paper, RF measurement and tuning results as well as results of the conditioning and dark current measurements will be presented and discussed.
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TUPP034 |
Transverse Effects due to Vacuum Mirror of RF Gun
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1613 |
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- I. Zagorodnov, M. Dohlus, M. Krasilnikov
DESY, Hamburg
- E. Gjonaj, S. Schnepp
TEMF, Darmstadt
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The transverse kick due to the vacuum mirror in the RF gun can negatively affect the beam emittance. In this contribution we estimate numerically and analytically the transverse wake function of European XFEL RF gun and apply it in beam dynamics studies of the transverse phase space.
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TUPC002 |
Design of a Tomography Module for the PITZ Facility
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1038 |
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- G. Asova, K. Floettmann
DESY, Hamburg
- D. J. Holder, B. D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
- S. Khodyachykh, S. A. Korepanov, M. Krasilnikov, S. Rimjaem, F. Stephan
DESY Zeuthen, Zeuthen
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The goal of the Photo Injector Test Facility at DESY in Zeuthen (PITZ) is to develop sources of high phase-space density electron beams that are required for the successful operation of SASE FELs. This requires detailed characterization of the sources and therefore the development of suitable advanced diagnostics. As part of the ongoing upgrade towards higher beam energies, new diagnostics components are being installed. An example is a tomography module for transverse phase space reconstruction which is designed to operate in the energy range between 15 and 40 MeV. The module consists of four observation screens with three FODO cells between them. A number of upstream quadrupoles are used to match the beam envelope parameters to the optics of the FODO lattice. This contribution presents the final design of the tomography module. Data from numerical simulations are used to illustrate the expected performance and to compare it to a simplified setup of two quadrupoles. The quality of the reconstruction is revised with the help of different algorithms.
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