Keyword: drift-tube-linac
Paper Title Other Keywords Page
MOPLR069 Implication of Manufacturing Errors on the Layout of Stabilization System and on the Field Quality in a Drift Tube Linac - RF DTL Error Study DTL, linac, simulation, emittance 290
 
  • R. De Prisco, A.R. Karlsson
    Lund University, Lund, Sweden
  • M. Eshraqi, Y.I. Levinsen, R. Miyamoto
    ESS, Lund, Sweden
 
  The field flatness and the layout of the stabilization system in a drift tube linac are strongly dependent on the manufacturing errors that affect the local resonant frequency. In this paper a methodology is presented to study, firstly, the sensitivity of the resonant frequency and of the field flatness to each geometrical parameter of the drift tubes; then a set of tolerances for each parameter is found and a stabilization system layout is defined in order to keep the field flatness within an acceptable limit.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR069  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPLR038 The DTL Post Coupler - An Ingenious Invention Turns 50 DTL, linac, cavity, proton 547
 
  • S. Ramberger
    CERN, Geneva, Switzerland
  • M.R. Khalvati
    IPM, Tehran, Iran
 
  In September 1967, the patent for "A method and device for stabilization of the field distribution in drift tube linac" has been filed by Edward A. Knapp, Donald A. Swenson, and James M. Potter of Los Alamos National Laboratory. It is this invention which to a good part led to the success of highly efficient Alvarez drift tube linacs (DTLs) in that it considerably reduces field errors. The explanation for why the post coupler when tuned correctly has such a strong stabilizing effect has been given at the time in an accompanying paper by describing the modal confluence of the accelerating mode band with the post-coupler mode band, turning a comparatively sensitive 0-mode structure into a stable pi/2-mode like structure. As ingenious as the invention of the post-coupler appears, as poor has been the way of finding its optimum length by relying mainly on trial and error. With the design of the Linac4 DTL at CERN, a new technique has been derived by a DTL equivalent circuit model. Understanding stabilization on an almost cell by cell level provides a new way of optimizing post-couplers of an entire structure with few measurements and even without the extraction of the circuit model itself. Previous approaches to post-coupler stabilization are reviewed and the new, straightforward and accurate technique is described and demonstrated in the stabilization of the Linac4 DTL structures.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR038  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)