• D. Saez de Jauregui, S. Casalbuoni, A.W. Grau, M. Hagelstein, E.M. Mashkina
  FZK, Eggenstein
• R. Cimino, M. Commisso
  INFN/LNF, Frascati (Roma)
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

Recent investigations with the cold bore superconducting undulator installed at ANKA indicate that the main contribution to the beam heat load is caused by electron bombardment. For a quantitative understanding of the problem a cold vacuum chamber for diagnostics has been designed. Among other important parameters (heat load, pressure, etc) this device shall monitor the spectrum of the low energy electrons bombarding the wall. In this contribution we report on the measurements of the spectrum of the low energy electrons bombarding the wall of the cold vacuum chamber in a room temperature region of the ANKA storage ring performed using a in house developed retarding field analyzer (RFA). The calibration of the RFA performed at the national laboratories of Frascati is also described.

• A. Plech, S. Casalbuoni, B. Gasharova, E. Huttel, Y.-L. Mathis, A.-S. Müller, K.G. Sonnad
  FZK, Karlsruhe
• A. Bartels
  CAP Konstanz, Konstanz
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

In a synchrotron radiation source coherent synchrotron radiation is emitted when the bunch length is comparable to the wavelength of the emitted radiation. To generate coherent THz (far IR) radiation, the ANKA storage ring is operated regularly with a dedicated low-alpha optics. Typical effective pulse lengths are of the order of 1 ps and below. In order to characterize the THz emission and beam oscillations in this mode a femtosecond laser system has been set up. This allows resolving the Terahertz electrical field by electro-optical sampling in a ZnTe crystal. The laser system consists of a 500 MHz repetition rate oscillator that can be phase locked to the repetition rate of the synchrotron. First results are presented. In contrast to previous approaches the high repetition rate is used in conjunction with a high frequency detection scheme in order to significantly increase the sensitivity of the detection. The discussion will concentrate on the limits in synchronization by locking the laser to either the bunch clock, a stripline signal in the ring or the visible light emission co-propagating with the THz radiation. The observations are compared to calculated pulse shapes.

• 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.

• K.G. Sonnad, I. Birkel, S. Casalbuoni, E. Huttel, D. Saez de Jauregui, N.J. Smale
  FZK, Eggenstein
• F. Caspers
  CERN, Geneva
• A.-S. Müller, K.G. Sonnad
  KIT, Karlsruhe
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

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

A superconducting undulator is installed in the ANKA electron storage ring. Electron clouds could potentially contribute to the heat load of this device. A microwave transmission type electron cloud diagnostic has been installed for the undulator section of the ANKA machine. We present the system layout with particular emphasis on the electron machine aspects. Hardware transfer function results and e-cloud data for different machine settings are discussed. Special care has been taken for front end filter design both on the microwave injection and pick-up side.

• K.G. Sonnad, I. Birkel, S. Casalbuoni, E. Huttel, N.J. Smale
  FZK, Eggenstein
• F. Caspers
  CERN, Geneva
• N. Hiller, A.-S. Müller, K.G. Sonnad
  KIT, Karlsruhe
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

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

The status of longitudinal and transverse Schottky observation systems for the synchrotron light source ANKA is presented. ANKA regularly operates in a dedicated low alpha mode with short bunches for the generation of coherent THz radiation. The Schottky measurement results are shown and compared with theoretical predictions for the regular as well as the different stages of the low alpha mode of operation. Special care had to be taken to control and mitigate the impact from strong coherent lines of the short bunches on the signal processing chain. The system setup is shown, expected and unexpected observations as well as applications are discussed.