• M. Krasilnikov
  DESY, Hamburg
• F. Stephan
  DESY Zeuthen, Zeuthen

The stability of the photo injector is a key issue for the successful operation of linac based free electron lasers. Several types of jitter can impact the stability of a laser driven RF gun. Fluctuations of the RF launch phase and the cathode laser energy have significant influence on the performance of a high brightness electron source. Bunch charge measurements are used to monitor the stability of the rf gun phase and the cathode laser energy. A basic measurement is the so called phase scan: the accelerated charge downstream of the gun is measured as a function of the launch phase, the relative phase of the laser pulses with respect to the RF. We describe a method which provides simultaneous information on rms jitters from phase scans at different cathode laser energies. Fluctuations of the rf gun phase together with cathode laser energy jitter have been measured at the Photo Injector test facility at DESY in Zeuthen (PITZ). Obtained results will be presented in comparison with direct independent measurements of corresponding instability factors. Dedicated beam dynamics simulations have been done in order to optimize the method performance.

Poster

• J.W. Bähr, A. Brinkmann, K. Flöttmann, S. Lederer, F. Obier, D. Reschke, S. Schreiber
  DESY, Hamburg
• W. Ackermann, W.F.O. Müller, S. Schnepp, T. Weiland
  TEMF, TU Darmstadt, Darmstadt
• H.M. Al-Juboori, A. Donat, U. Gensch, H.-J. Grabosch, L. Hakobyan, R. Heller, M. Hänel, Ye. Ivanisenko, L. Jachmann, M.A. Khojoyan, G. Klemz, W. Köhler, G. Koss, M. Krasilnikov, A. Kretzschmann, H. Leich, M. Mahgoub, J. Meissner, D. Melkumyan, M. Otevrel, M. Penno, B. Petrosyan, M. Pohl, S. Rimjaem, C. Rueger, M. Sachwitz, B. Schoeneich, J. Schultze, A. Shapovalov, F. Stephan, M. Tanha, G. Trowitzsch, G. Vashchenko, L.V. Vu, T. Walther, X.H. Wang, S. Weisse, R.W. Wenndorff, M. Winde
  DESY Zeuthen, Zeuthen
• G. Asova, A. Bonev, I.I. Tsakov
  INRNE, Sofia
• D.J. Holder, B.L. Militsyn, B.D. Muratori
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• P.M. Michelato, L. Monaco, C. Pagani, D. Sertore
  INFN/LASA, Segrate (MI)
• V.V. Paramonov
  RAS/INR, Moscow
• D. Richter
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin
• J. Roßbach, J. Rönsch-Schulenburg
  Uni HH, Hamburg
• J. Saisut
  FNRF, Chiang Mai
• W. Sandner, I. Will
  MBI, Berlin

The Photo Injector Test facility at DESY Zeuthen site (PITZ) is dedicated to developing and optimizing high brightness electron sources for short wavelength Free-Electron Lasers (FELs) like FLASH and the European XFEL, both in Hamburg (Germany). Since October 2009 a major upgrade has been ongoing with the goal of improving the accelerating components, the photocathode drive laser system, and the beam diagnostics. The previously operated and fully characterized gun was brought to FLASH and will go into operation soon. A gun of the same type is installed now in PITZ. The conditioning has started and the gun will be characterized throughout 2010. A new booster cavity, Cut Disk Structure (CDS), was developed and will be mounted at PITZ in spring 2010. The booster cavity will be able to accelerate electrons above 20 MeV/c and will be suitable for long RF pulses. The most important upgrade of the diagnostics system will be the implementation of a phase space tomography module (PST) consisting of three FODO cells each surrounded by two screen stations. The results of commissioning, gun and booster conditioning and the very first measurements will be reported.