A   B   C   D   E   F   G   H   I   K   L   M   O   P   Q   R   S   T   U   V    

free-electron-laser

  
Paper Title Other Keywords Page
MO101 Advanced Analysis in Nanospace: Research with the XFEL electron, laser, radiation 1
 
  • H. Dosch
    MPI, Stuttgart
  Little happens in industrialised countries without the use of high-tech materials which are the building blocks of all modern technologies ranging from information, communication, health, energy and environment to transport. In the last decades the development of novel materials has progressed at a breathtaking rate. This has become possible through our microscopic insight into the atomistic structure of condensed matter which finally enabled us to assemble new material systems atom-by-atom. These days, we are facing a revolution in the investigation of nanospace: Through new concepts in accelerator physics, electrons can be forced to emit short-pulsed x-ray laser radiation. Such a futuristic European x-ray free electron laser (XFEL) laboratory is currently being constructed and will allow mankind to finally get holographic snapshots of the motion of atoms and electrons in materials. Ultimate insights into matter, as the realtime-observation of the formation and the breaking of molecular bonds, sound like science fiction, but could become reality in less than a decade, if Europe embarks today into this bold adventure which will lead us into unexplored dimensions of nanospace.  
 
MO201 Linac Coherent Light Source (LCLS) – Accelerator System Overview linac, damping, feedback, simulation 7
 
  • P. Krejcik, Z. Huang, J. Wu
    SLAC, Menlo Park, California
  • P. Emma
    SLAC/ARDA, Menlo Park, California
  The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL). Pulses of LCLS x-ray FEL will be several orders of magnitude brighter and shorter than most existing sources. These characteristics will enable frontier new science in several areas. To ensure the vitality of FEL lasing, it is critical to preserve the high quality of the electron beam during the acceleration and compression. We will give an overview of the LCLS accelerator system. We will address design essentials and technique challenges to satisfy the FEL requirements. We will report studies on the microbunching instability suppression via a Laser-Heater. The studies clearly prove the necessary of adding the Laser-Heater and show how effectively this Laser-Heater suppresses the instability by enhancing the Landau damping. We will report how to minimize the sensitivity of the final energy spread and the peak current to various system ‘jitters’. To minimize this sensitivity, a feedback system is required together with other diagnostics. With all these considerations, full start-to-end simulations show saturation at 1.5 Å, though the LCLS is expected to be a very challenging machine.  
Transparencies
 
MOP49 Status And Operating Experience of The TTF Coupler vacuum, klystron, linac, superconductivity 156
 
  • W.-D. Möller, D. Kostin
    DESY, Hamburg
  Five accelerating modules are installed in the VUV FEL linac so far. This includes 40 high power couplers connected to the superconducting cavities, eight in every module. All of them are processed and operated up to the cavity performance limits. The coupler processing procedure is described. The performance in relation to the test results on the coupler test stands are discussed.  
Transparencies
 
THP48 A High-Resolution S-band Down-Converting Digital Phase Detector for SASE FEL Use linac, photon, feedback, simulation 715
 
  • A.E. Grelick, N.D. Arnold
    ANL/APS, Argonne, Illinois
  • J. Carwardine, N. Dimonte, A. Nassiri, T. Smith
    ANL, Argonne, Illinois
  Each of the rf phase detectors in the Advanced Photon Source linac consists of a module that down converts from S-band to 20 MHz followed by an analog I/Q detector. Phase is calculated from one digitized sample per pulse each of I and Q. The resulting data has excellent long-term stability but is noisy enough so that a number of samples must be averaged to get a usable reading. The more recent requirement to support a SASE FEL has presented the need to accurately resolve the relative phase of a single pulse. Replacing analog detection with digital sampling and replacing internal intermediate frequency reference oscillators with a lower noise external oscillator were used to control the two largest components of noise. The implementation of a central, ultralow noise reference oscillator and a distribution system capable of maintaining the low phase noise is described, together with the results obtained to date. The principal remaining technical issue is determining the processing power required as a function of measurement channels per processor, measured pulse repetition rate, intrapulse data bandwidth, and digital filter characteristics. The options and tradeoffs involved and the present status are discussed.