• A. Hofmann, M. Fitterer, M. Klein, A.-S. Müller, K.G. Sonnad
  KIT, Karlsruhe
• G. Blokesch
  PPT, Dortmund
• E. Huttel, N.J. Smale
  FZK, Eggenstein
• S. Marsching, T. Weis
  DELTA, Dortmund
• C. Piel
  ACCEL, Bergisch Gladbach
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320.

The microtron of the ANKA injector is presently equipped with a diode- type electron gun, which produces long pulses. A new thermionic DC triode-type electron gun has been ordered and foreseen for installation in the ANKA injector. The new gun allows single bunch as well as long pulse operation, thus offering the possibility to study beam properties in single bunch operation. This is particularly of interest for the investigation of the short bunch dynamics in the generation of coherent THz radiation. Furthermore, the new gun will make time resolved measurement possible. Simulations of the gun-to-microtron transport with special emphasis on the emittance evolution e.g. due to space charge have been done. Measurements of the gun performance are presently underway and are summarised in this paper.

• A.-S. Müller, I. Birkel, E. Huttel, Y.-L. Mathis, N.J. Smale
  FZK, Eggenstein
• E. Bründermann
  Ruhr-Universität Bochum, Bochum
• T. Bückle, M. Fitterer, S. Hillenbrand, N. Hiller, A. Hofmann, V. Judin, M. Klein, S. Marsching, K.G. Sonnad
  KIT, Karlsruhe
• J. Feikes, M.V. Hartrott
  HZB, Berlin
• H.W. Huebers, A. Semenov
  DLR, Berlin
• R. Klein, R. Müller, G. Ulm
  PTB, Berlin
• G. Wüstefeld
  BESSY GmbH, Berlin

Funding: This work has partly been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320.

In synchrotron radiation sources coherent radiation is emitted when the bunch length is comparable to or shorter than the wavelength of the emitted radiation. A detector system based on a superconducting NbN ultra-fast bolometer with an intrinsic response time of about 100 ps jointly developed by the University of Karlsruhe (Institute of micro- and nanoelectronic systems) and German Aerospace Center (Berlin) was used to resolve the radiation emitted from single bunches. This paper reports the observations made during measurements at the MLS and ANKA storage rings.

• M. Fitterer, A.-S. Müller
  KIT, Karlsruhe
• E. Adli, H. Burkhardt, B. Dalena, G. Rumolo, D. Schulte
  CERN, Geneva
• I. Ahmed
  NCP, Islamabad
• A. Latina
  Fermilab, Batavia

We report about generic halo and tail simulations and estimates. Previous studies were mainly focused on very high energies as relevant for the beam delivery systems of linear colliders. We have now studied, applied and extended these simulations to lower energies as relevant for the CLIC drive beam.

• M. Klein, T. Bückle, M. Fitterer, A. Hofmann, A.-S. Müller, K.G. Sonnad
  KIT, Karlsruhe
• I. Birkel, E. Huttel, Y.-L. Mathis
  FZK, Karlsruhe

Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320.

In synchrotron light sources, coherent synchrotron radiation (CSR) is emitted at wavelengths comparable to and longer than the bunch length. One effect of the CSR wake field is the distortion of the bunch distribution, which increases with higher currents. In the theoretical calculations, a threshold exists beyond which the solutions begin to diverge. On the other hand, the CSR wake can also excite a micorbunching instability which prevents stable emission of CSR for high currents and leads to highly intense bursts of radiation. In this paper the development of the calculated bunch shapes and the corresponding moments of the current distribution for varying bunch currents are studied. It can be shown that the numerical threshold beyond which the solutions diverge, does not coincide with the observed bursting-stable-threshold at the ANKA storage ring, which agrees well with theory.