Author: Vogt, M.
Paper Title Page
Coherent Accelerator-based High Field THz Radiation at FLASH II  
  • T. Golz, V. B. Asgekar, B. Faatz, G. Geloni, N. Stojanovic, M. Tischer, P. Vagin, M. Vogt
    DESY, Hamburg, Germany
  • M. Gensch
    HZDR, Dresden, Germany
  • P. Vobly
    BINP SB RAS, Novosibirsk, Russia
  Funding: BMBF grant no. 05K10CHC + 05K10KEB + 05K12CH4
Linear accelerator based light sources with their tunable broad spectral range (THz to hard X-rays regime) and their ability to generate ultra-short pulses with peak intensities many orders of magnitude higher then synchrotron sources, gave rise to a new field of ultrafast physics. In the THz range, the ability of 4th gen. light sources to generate pulses with e-field strengths up to 1 GV/m opened the door to the field of non-linear THz spectroscopy and THz-controlled material science. The main advantage of accelerator-based THz is its scaleability. As the process is not bound to a particular medium, but occurs in the accelerator vacuum, it bypasses the limitation of table top sources. In addition, it has been demonstrated that coherent THz radiation can be generated along femtosecond X-ray pulses in 4th Generation X-ray Light sources such as FLASH [1,2,3] and LCLS [4]. This opens up the opportunity for naturally synchronized THz pump X-ray probe experiments on a few femtosecond time scale [1,2,4]. Here we present the design for the THz source at FLASH2, which takes new findings [5] and challenges into account that we face during the radiation transport to the experimental hall.
WEB05 FLASH: First Soft X-ray FEL Operating Two Undulator Beamlines Simultaneously 635
  • K. Honkavaara, B. Faatz, J. Feldhaus, S. Schreiber, R. Treusch, M. Vogt
    DESY, Hamburg, Germany
  FLASH, the free electron laser user facility at DESY (Hamburg, Germany), has been upgraded with a second undulator beamline FLASH2. After a shutdown to connect FLASH2 to the FLASH linac, FLASH1 is back in user operation since February 2014. Installation of the FLASH2 electron beamline has been completed early 2014, and the first electron beam was transported into the new beamline in March 2014. The commissioning of FLASH2 takes place in 2014 parallel to FLASH1 user operation. This paper reports the status of the FLASH facility, and the first experience of operating two FEL beamlines.  
slides icon Slides WEB05 [2.481 MB]  
THP073 Optics Measurements at FLASH2 902
  • M. Scholz, B. Faatz, M. Vogt, J. Zemella
    DESY, Hamburg, Germany
  FLASH2 is a newly build second beam line at FLASH, the soft X-ray FEL at DESY, Hamburg. Unlike the existing beam line FLASH1, it is equipped with variable gap undulators. This beam line is currently being commissioned. Both undulator beam lines of FLASH are driven by a common linear accelerator. Fast kickers and a septum are installed at the end of the linac to distribute the electron bunches of every train between FLASH1 and FLASH2. A specific beam optic in the extraction arc with horizontal beam waists in the bending magnets is mandatory in order to mitigate CSR effects. Here we will show first results of measurements and compare to simulations.