Accelerator Technology
Dynamics 06: EM Fields
Paper Title Page
TUP012 Computer Simulations of Waveguide Window and Coupler Iris for Precision Matching 832
 
  • S.W. Lee
    ORNL RAD, Oak Ridge, Tennessee, USA
  • Y.W. Kang, K.R. Shin, A.V. Vassioutchenko
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
A tapered ridge waveguide iris input coupler and a waveguide ceramic disk windows are used on each of six drift tube linac (DTL) cavities in the Spallation Neutron Source (SNS). The coupler design employs rapidly tapered double ridge waveguide to reduce the cross section down to a smaller low impedance transmission line section that can couple to the DTL tank easily. The impedance matching is done by adjusting the dimensions of the thin slit aperture between the ridges that is the coupling element responsible for the power delivery to the cavity. Since the coupling is sensitive to the dimensional changes of the aperture, it requires careful tuning for precise matching. Accurate RF simulation using latest 3-D EM code is desirable to help the tuning for maintenance and spare manufacturing. Simulations are done for the complete system with the ceramic window and the coupling iris on the cavity to see mutual interaction between the components as a whole.
 
 
WEOBS1 The Berkeley Lab Laser Accelerator (BELLA): A 10 GeV Laser Plasma Accelerator 1416
 
  • W. Leemans, R.M. Duarte, E. Esarey, D.S. Fournier, C.G.R. Geddes, D. Lockhart, C.B. Schroeder, C. Tóth, J.-L. Vay, S. Zimmermann
    LBNL, Berkeley, California, USA
 
  An overview is presented of the design of a 10 GeV laser plasma accelerator (LPA) that will be driven by a PW-class laser system and of the BELLA Project, under which the required Ti:sapphire laser system for the acceleration experiments is being installed. The basic design of the 10 GeV stage aims at operation in the quasi-linear regime, where the laser excited wakes are largely sinusoidal and allow acceleration of electrons and positrons. Simulations show that a 10 GeV electron beam can be generated in a meter scale plasma channel guided LPA operating at a density of about 1017 cm-3 and powered by laser pulses containing 30-40 J of energy in a 50-200 fs duration pulse, focused to a spotsize of 50-100 micron. The lay-out of the facility and laser system will be presented as well as the progress on building the facility.