Author: Frisch, J.C.
Paper Title Page
TUAL2 Commissioning the New LCLS X-band Transverse Deflecting Cavity with Femtosecond Resolution 308
  • P. Krejcik, F.-J. Decker, Y. Ding, J.C. Frisch, Z. Huang, J.R. Lewandowski, H. Loos, J.L. Turner, J.W. Wang, M.-H. Wang, J.J. Welch
    SLAC, Menlo Park, California, USA
  • C. Behrens
    DESY, Hamburg, Germany
  Funding: This work was supported by Department of Energy Contract No. DE-AC0276SF00515
The new X-band transverse deflecting cavity began operation in May 2013 and is installed downstream of the LCLS undulator. It is operated at the full 120 Hz beam rate without interfering with the normal FEL operation for the photon users. The deflected beam is observed on the electron beam dump profile monitor, which acts as an energy spectrometer in the vertical plane. We observe, on a pulse by pulse basis, the time resolved energy profile of the spent electron beam from the undulator. The structure is powered from a 50 MW X-band klystron, giving a 48 MV kick to the beam which yields a 1 fs rms time resolution on the screen. We have measured the longitudinal profile of the electron bunches both with the FEL operating and with the lasing suppressed, allowing reconstruction of both the longitudinal profile of the incoming electron beam and the time-resolved profile of the X-ray pulse generated in the FEL. We are immediately able to see whether the bunch is chirped and which parts of the bunch are lasing, giving us new insight into tuning the machine for peak performance. The performance of the system will be presented along with examples of measurements taken during LCLS operation.
slides icon Slides TUAL2 [9.210 MB]  
TUPC22 Cavity Beam Position Monitor in Multiple Bunch Operation for the ATF2 Interaction Point Region 419
  • Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, S.T. Boogert, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin, C. Perry
    JAI, Oxford, United Kingdom
  • J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White
    SLAC, Menlo Park, California, USA
  • Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  The Accelerator Test Facility 2 (ATF2) at KEK, Japan, is a scaled test beam line for the international linear collider (ILC) final focus system. There are two goals: firstly, to demonstrate focusing to 37 nm vertical beam size; secondly, to achieve a few nanometer level beam orbit stability at the focus point (the Interaction Point (IP)) in the vertical plane. High-resolution beam position monitors around the IP area (IPBPMs) have been developed in order to measure the electron beam position in that region with a resolution of a few nanometers in the vertical plane. Currently, the standard operation mode at ATF2 is single bunch, however, multiple bunch operation with a bunch spacing similar to the one foreseen for the ILC (around 300 ns) is also possible. IPBPMs have a low Q value resulting in a decay time of about 30 ns, and so should be able to measure the beam position of individual bunches without any significant performance degradation. The IPBPMs in the ATF2 extraction beam line have been tested in multibunch regime. This paper analyses the signals, processing methods and results for this mode.  
poster icon Poster TUPC22 [1.050 MB]