Author: Renneke, R.M.
Paper Title Page
WG1012
Development of High-average-current RF Injectors  
 
  • D.C. Nguyen, H.L. Andrews, C.E. Heath, F.L. Krawczyk, N.A. Moody, R.M. Renneke, W.M. Tuzel
    LANL, Los Alamos, New Mexico, USA
  • J.W. Lewellen
    NPS, Monterey, California, USA
 
  A key component of the high-average-power free-electron laser is a low emittance, high-average-current RF injector. The RF injector typically consists of a high gradient structure with integer-and-a-half RF cells. The cathode is located on the wall of the first half cell where very high accelerating gradients are applied to quickly accelerate electrons to relativistic velocities. While the average gradient can exceed 100 MV/m in a pulsed normal conducting RF injector, it is only 7 MV/m in a cw normal-conducting RF gun and approximately 25 MV/m in a cw superconducting RF gun. Emittance compensation has been achieved in NCRF injectors with an axial solenoid magnetic field near the photocathode to generate high-brightness electron beams. The use of emittance compensation eliminates the need for ultrahigh accelerating gradients, and enables the generation of electron beams with normalized rms emittance on the order of a few mm-mrad. This paper reviews the current state-of-the-art of cw, high-average-current RF injectors, using both normal-conducting and superconducting RF accelerator technologies.  
slides icon Slides WG1012 [0.612 MB]