Author: Faatz, B.
Paper Title Page
THPC081 Status of the Free-Electron Laser FLASH at DESY 3080
 
  • M. Vogt, B. Faatz, J. Feldhaus, K. Honkavaara, S. Schreiber, R. Treusch
    DESY, Hamburg, Germany
 
  The free-electron laser facility FLASH at DESY, Germany has been upgraded in 2010. Now, FLASH delivers an electron beam energy up to 1.25 GeV. The longitudinal phase-space is linearized by 3.9 GHz superconducting cavities. The facility delivers to users ultra-short laser like radiation pulses in the range of less than 50 fs to 200 fs in the soft X-ray wavelenth range from 44 down to 4.1 nm. FLASH provides hundreds to thousands pulses per second to users with unprecedented peak brilliance. FLASH will be upgraded with a second undulator beam line and an additional experimental hall. Construction starts Autumn 2011. We summarize the operational status of the ongoing 3rd user period.  
 
THPC111 Operation of an L-band RF Gun with Pulses Inside the Burst Mode RF Pulse 3146
 
  • V. Vogel, V. Ayvazyan, B. Faatz, K. Flöttmann, D. Lipka, P. Morozov, H. Schlarb, S. Schreiber
    DESY, Hamburg, Germany
 
  The Free-Electron Laser in Hamburg (FLASH) is a user facility since 2005, delivering femtosecond short radiation pulses in the wavelength range between 4.1 and 44 nm using the SASE principle. In FLASH, the electron beam is accelerated to 1.25 GeV with L-band superconducting cavities. The electron source is a normal conducting RF-gun photoinjector. The L-band standing wave RF gun has one and a half cells. The gun is operated in burst mode with an RF pulse length of up to 900 microseconds and a repetition rate of 10 Hz. Several hundreds to thousands of bunches are accelerated per second. With 5 MW of pulsed forward power, the dissipated power inside the RF gun is 45 kW. In this paper we propose an operational mode which allows us to reduce the dissipated power to ease operation or to increase the effective duty cycle in the gun by pulsing the gun within one burst. We report on first experimental results at FLASH, where an RF burst of 46μRF-pulses with a length of 10 microseconds separated by 10 microseconds has been successfully generated reducing the dissipated power by a factor of 2.