• V. Judin, S. Hillenbrand, N. Hiller, A. Hofmann, E. Huttel, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale, K.G. Sonnad, P.F. Tavares
  KIT, Karlsruhe
• H.W. Huebers
  Technische Universität Berlin, Berlin
• A. Semenov
  DLR, Berlin

Since a few years CSR-Radiation created in low alpha mode is provided by the ANKA light source of the KIT*. Depending on the bunch current, the radiation is emitted in bursts of high intensity. These bursts display a time evolution which can be observed only on long time scales with respect to the revolution period. The intensity of the emitted radiation during a burst is significantly increased w.r.t. steady state emission. Some users of the THz radiation don't require particularly constant emission characteristics and could profit from the higher intensity. A better understanding of the long term behaviour of those bursts could help to improve the conditions for those users. We have investigated THz radiation in multiturn mode with a hot electron bolometer. Its time response of 165ps allowed us to resolve the signals of individual bunches. Using a 6GHz LeCroy oscilloscope for data acquisition, we were able to save up to 1.6ms long signal sequences at a sampling rate of 20GS/s. This amount of data corresponds to over 4000 bunch revolutions and allows turn-by-turn signal tracking of desired bunches. In single bunch mode we are able to take segmented data to avoid a huge overhead.

* KIT - Karlsruhe Institute for Technology

• A.-S. Müller, I. Birkel, M. Fitterer, S. Hillenbrand, N. Hiller, A. Hofmann, E. Huttel, K.S. Ilin, V. Judin, M. Klein, S. Marsching, Y.-L. Mathis, P. Rieger, M. Siegel, N.J. Smale, K.G. Sonnad, P.F. Tavares
  KIT, Karlsruhe
• H.W. Huebers
  Technische Universität Berlin, Berlin
• A. Semenov
  DLR, Berlin

In synchrotron radiation sources coherent radiation is emitted when the bunch length is comparable to or shorter than the wavelength of the emitted radiation. At the ANKA storage ring this radiation is observed as so-called edge radiation (emitted in the fringe field of a bending magnet). This radiation exhibits a radial polarisation pattern. The observed pattern, however, is influenced by the radiation transport in the beam line. A detector system based on a superconducting NbN ultra-fast bolometer with an intrinsic response time of about 100 ps as well as conventional Si bolometers were used to study the beam polarisaion. This paper reports the observations made during measurements.