Author: Judin, V.
Paper Title Page
MOPEA014 Temporal and Spectral Observation of Laser-induced THz Radiation at DELTA 94
  • P. Ungelenk, H. Huck, M. Huck, M. Höner, S. Khan, R. Molo, A. Schick
    DELTA, Dortmund, Germany
  • N. Hiller, V. Judin
    KIT, Karlsruhe, Germany
  Funding: Work supported by the DFG, the BMBF, the Federal State NRW, the Initiative and Networking Fund of the Helmholtz Association, and the German Federal Ministry of Education and Research.
Coherent THz pulses caused by a laser-induced density modulation of the electron bunches are routinely produced and observed at DELTA, a 1.5 GeV synchrotron light source operated by the TU Dortmund University. New measurements performed with a fast hot-electron bolometer allow insight into the turn-by-turn evolution of these pulses. Furthermore, first results from a Fourier transform infrared spectrometer, which is currently under commissioning, are presented.
MOPEA019 Studies of Bunch-bunch Interactions in the ANKA Storage Ring with Coherent Synchrotron Radiation using an Ultra-fast Terahertz Detection System 109
  • A.-S. Müller, B.M. Balzer, C.M. Caselle, N. Hiller, M. Hofherr, K.S. Ilin, V. Judin, B. Kehrer, S. Marsching, S. Naknaimueang, M.J. Nasse, J. Raasch, A. Scheuring, M. Schuh, M. Schwarz, M. Siegel, N.J. Smale, J.L. Steinmann, P. Thoma, M. Weber, S. Wuensch
    KIT, Karlsruhe, Germany
  Funding: Supported by Initiative and Networking Fund of the Helmholtz Association under contract No. VH-NG-320 and German Federal Ministry of Education and Research under Grant. Noss. 05K10VKC and 05K2010VKD
In the low-alpha operation mode of the ANKA synchrotron light source, coherent synchrotron radiation (CSR) is emitted from short electron bunches. Depending on the bunch current, the radiation shows bursts of high intensity. These bursts of high intensity THz radiation display a time evolution which can be observed only on long time scales with respect to the revolution period. In addition, long range wake fields can introduce a correlation between the bunches within a bunch train and thus modify the observed behavior. A novel detection system consisting of an ultra-fast superconducting THz detector and data acquisition system was used to investigate correlations visible on the bursting pattern and to study the interactions of very short pulses in the ANKA storage ring.
MOPEA020 Comparison of Different Approaches to Determine the Bursting Threshold at ANKA 112
  • P. Schönfeldt, N. Hiller, V. Judin, A.-S. Müller, M. Schwarz, J.L. Steinmann
    KIT, Karlsruhe, Germany
  The synchrotron light source ANKA at the Karlsruhe Institute of Technology provides a dedicated low-α-optics. In this mode bursting of Coherent Synchrotron Radiation (CSR) is observed for bunch charges above a threshold that depends on beam parameters. This threshold can be determined by several approaches, e.g. bunch lengthening or changes in the THz radiation spectra. This paper compares different methods and their implementation at the ANKA storage ring outlining their advantages, disadvantages and limitations, including reliability and possibility of real time analysis.  
MOPME014 Electro-optical Bunch Length Measurements at the ANKA Storage Ring 500
  • N. Hiller, A. Borysenko, E. Hertle, E. Huttel, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, A. Plech, M. Schuh, S.N. Smale
    KIT, Eggenstein-Leopoldshafen, Germany
  • P. Peier, V. Schlott
    PSI, Villigen PSI, Switzerland
  • B. Steffen
    DESY, Hamburg, Germany
  Funding: Supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320 and by the German Federal Ministry of Education and Research under contract number 05K10VKC
A setup for near-field electro-optical bunch length measurements has recently been installed into the UHV system of the ANKA storage ring. For electro-optical bunch length measurements during ANKA's low alpha operation, a laser pulse is used to probe the field induced birefringence in an electro-optical crystal (GaP in our case). The setup allows for both electro-optical sampling (EOS, multi-shot) and spectral decoding (EOSD, single- and multi-shot) measurements. This paper presents first results and discusses challenges of this method employed for the first time at a storage ring.
MOPME015 Numerical Wakefield Calculations for Electro-optical Measurements 503
  • B. Kehrer, A. Borysenko, E. Hertle, N. Hiller, V. Judin, S. Marsching, A.-S. Müller, M.J. Nasse, M. Schuh
    KIT, Karlsruhe, Germany
  Funding: This project is funded by the Federal Ministry of Education and Research under the contract number 05K10VKC
The technique of electro-optical measurements allows precise and single-shot measurements of the bunch length and shape. The installation of such a near-field setup changes the impedance of the storage ring and the corresponding effects have to be studied carefully. One possibility is to use numerical codes for simulating the wakefields induced by the setup. Such simulations has been done using the wakefield solver implemented in the CST Studio Suite. In this paper we present the simulation results together with first measurements.
WEOBB202 Ultra-fast Data Acquisition System for Coherent Synchrotron Radiation Based on Superconducting Terahertz Detectors 2094
  • C.M. Caselle, M. Hofherr, K.S. Ilin, V. Judin, A. Kopmann, A. Menshikov, A.-S. Müller, M. Siegel, N.J. Smale, P. Thoma, M. Weber, S. Wuensch
    KIT, Eggenstein-Leopoldshafen, Germany
  • B.M. Balzer, S. Cilingaryan
    Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
  The ANKA synchrotron radiation source located at the Karlsruhe Institute of Technology in Germany operates in the energy range between 0.5-2.5GeV and provides coherent synchrotron radiation. To resolve the ultra-short terahertz pulses emitted by a single bunch, thin YBCO superconducting film detectors have been developed. A response time of 45ps was determined as the FWHM at the output of the analog amplifier. A novel and high accuracy data acquisition architecture for sampling of the individual ultra-short terahertz pulses combined with real-time data processing based on GPUs for coherent synchrotron radiation is presented. The digitizer board is a made-in-house board designed for sampling of the fast pulse signals with pulse width between few tens of picosecond until 100ps. For each terahertz pulse five samples are acquired with a minimum sampling time of 3ps. A prototype setup with terahertz YBCO detectors, digitizer boards and the high-throughput FPGA framework has been successfully developed and tested at ANKA. The overview of the experimental setup including the YBCO detector technology and the preliminary results with single and multi-bunch filling pattern will be discussed.  
slides icon Slides WEOBB202 [2.416 MB]  
WEPEA011 Bursting Patterns of Coherent Synchrotron Radiation in the ANKA Storage Ring 2516
  • M. Schwarz, V. Judin, A.-S. Müller
    KIT, Karlsruhe, Germany
  • M. Klein
    SOLEIL, Gif-sur-Yvette, France
  We report measurements of bursting patterns of coherent synchrotron radiation (CSR) for a wide range of single bunch currents at the ANKA storage ring. The radiation was detected with a fast THz detector, a Hot Electron Bolometer, and its signal acquired with both a spectrum analyzer and an external sampling oscilloscope. Both analysis methods consistently show the onset of bursting at a threshold current with the appearance of strong high frequency bands with higher harmonics in the several 10th of kHz range. For currents higher than twice the threshold value an abrupt change in the bursting pattern occurs. These results are compared with different numerical models solving the one-dimensional Vlasov-Fokker-Planck equation.  
WEPEA012 Study of Laser Wakefield Accelerators as Injectors for Synchrotron Light Sources 2519
  • S. Hillenbrand, V. Judin, A.-S. Müller
    KIT, Karlsruhe, Germany
  • R.W. Aßmann, S. Hillenbrand
    CERN, Geneva, Switzerland
  • O. Jansen, A.M. Pukhov
    HHUD, Dusseldorf, Germany
  Short bunch lengths, high beam energies, and small facility footprint make Laser Wakefield Accelerators (LWFA) very interesting as injectors for Synchrotron Light Sources. In this paper, we describe exemplary investigations for the ANKA storage ring.