Author: Hiller, N.
Paper Title Page
TUPC085 Observation of Microwave Radiation using Low-cost Detectors at the ANKA Storage Ring 1203
 
  • V. Judin, N. Hiller, A. Hofmann, E. Huttel, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller, M.J. Nasse, N.J. Smale
    KIT, Karlsruhe, Germany
  • F. Caspers
    CERN, Geneva, Switzerland
  • P. Peier
    PSI, Villigen, Switzerland
 
  Funding: Work supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320
Synchrotron light sources emit Coherent Synchrotron Radiation (CSR) for wavelengths longer than or equal to the bunch length. At most storage rings CSR cannot be observed because the waveguide cuts off radiation with long wavelengths. There are different approaches for shifting the CSR to shorter wavelengths that can propagate through the beam pipe, e.g.: The accelerator optics can be optimized for a low momentum compaction factor, thus reducing the bunch length. Alternatively, laser slicing can modulate substructures on long bunches. Both techniques extend the CSR spectrum to shorter wavelengths, so that CSR is emitted at wavelengths above the waveguide cut off. Usually fast detectors, like superconducting bolometer detector systems or Schottky barrier diodes, are used for observation of dynamic processes in accelerator physics. In this paper, we present observations of microwave radiation at ANKA using an alternative detector, a LNB (Low Noise Block) system. These devices are usually used in standard TV-SAT-receivers and are very cheap. We determined the time response of LNBs to be below 100 ns. The sensitivity of LNBs is optimized to detect very low intensity "noise-like" signals.
 
 
TUPC086 A Setup for Single Shot Electro Optical Bunch Length Measurements at the ANKA Storage Ring 1206
 
  • N. Hiller, E. Huttel, A.-S. Müller, A. Plech
    KIT, Karlsruhe, Germany
  • F. Müller, P. Peier, V. Schlott
    PSI, Villigen, Switzerland
 
  Funding: Supported by the Initiative and Networking Fund of the Helmholtz Association under VH-NG-320. Sponsored by the German Federal Ministry of Education and Research under contract number 05K10VKC
Single shot electro optical bunch length measurements, in particular using spectral decoding, are foreseen for the ANKA storage ring. This will allow to resolve fast changes of bunch deformation and structure during the low alpha operation (2-15 ps rms bunch length). This technique uses a chirped laser pulse to probe the field induced birefringence in an electro optical crystal. The laser pulse is then analyzed in a single shot spectrometer. To obtain the birefringence modulation one can either use the near field of the electron bunch (placing the crystal close to the electron bunch in the UHV system of the storage ring), or the far field (coherent synchrotron radiation in the THz range at a THz-/IR-Beamline). The laser needs to supply: sufficient tunability of pulse length, a wide spectrum to allow for a sub-ps resolution. Additionally it must provide a mode-locked operation synchronized to the bunch revolution clock. For this purpose, a mode locked Ytterbium fibre laser system which operates at 1030 nm has been developed at the Paul-Scherrer Institute in Switzerland. We give an overview over the experimental set up in the ANKA storage ring and the status of the project.
 
 
TUPC087 Filling Pattern Measurements at the ANKA Storage Ring 1209
 
  • B. Kehrer, N. Hiller, A. Hofmann, E. Huttel, V. Judin, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale
    KIT, Karlsruhe, Germany
 
  For many accelerator physics studies, e.g. the investigation of coherent synchrotron radiation (CSR), a precise knowledge of the quantitative filling pattern (i.e. the number of electrons per bunch) is essential. This can be achieved by either using a linear detector (analog recording) or by employing the method of time-correlated single photon counting (TCSPC). At the ANKA storage ring both methods are in use. The analogue detection is based on the signal from a stripline or annular electrode, the TCSPC uses a Single Photon Avalanche Diode (SPAD). In this paper, we describe the experimental set-ups and present results of a comparison of the two techniques for single as well as for multi bunch filling patterns.  
 
TUPO007 FLUTE, a Linac Based THz Source 1458
 
  • S. Naknaimueang, M. Schwarz
    Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
  • R. Abela, H.-H. Braun, R. Ganter, B. Patterson
    PSI, Villigen, Switzerland
  • A.H. Albert, T. Baumbach, M. Hagelstein, N. Hiller, E. Huttel, V. Judin, B. Kehrer, R. Kubat, S. Marsching, W. Mexner, A.-S. Müller, M.J. Nasse, A. Plech, R. Rossmanith, M. Schuh
    KIT, Karlsruhe, Germany
  • M.T. Schmelling
    MPI-K, Heidelberg, Germany
 
  We propose a versatile THz source named FLUTE (“Ferninfrarot Linac- Und Test-Experiment”) based on a 30 - 50 MeV S-band linac with bunch compressor, that shall not only provide high field THz pulses applications but shall also serve as a test facility to study important accelerator physics issues. This is also of importance in view of the planned utltra-broadband THz to mid infrared user facility TBONE. Special emphasis is put on studies of bunch compression and beam stability as a function of bunch charge (0.1-5 nC) and of different generation mechanisms of coherent radiation (CSR, CER, CTR). This paper describes the design and layout of the proposed FLUTE machine and presents results of beam dynamic calculations with the tracking programs ASTRA and CSRtrack.  
 
THPC021 Status of Bunch Deformation and Lengthening Studies at the ANKA Storage Ring 2951
 
  • N. Hiller, A. Hofmann, E. Huttel, V. Judin, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller
    KIT, Karlsruhe, Germany
 
  Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320.
At the ANKA storage ring (Karlsruhe, Germany) we use a Hamamatsu synchroscan streak camera to study the current dependent bunch lengthening and deformation effects . Previously the camera was used at an IR port, being available only occasionally. In October 2010, a dedicated “beam line” for the streak camera became operational. It is designed to have minimum dispersion and sufficient  flux in the optical range at which the camera is most sensitive. This allows us to measure bunch profiles for a single bunch with a charge of less than 15 pC (40 μA), previously more than 55 pC were required to obtain a comparable signal.  Along with the design and built-up, we present further measurements of bunch length and shape for different momentum compaction factors, RF voltages, beam energies and bunch charges to provide a complete bunch length map of  the low alpha mode at ANKA.