Author: Dallin, L.O.
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THPOW036 Evaluation of Immutability against Radiation-induced Demagnetization for a Hybrid Wiggler with NdFeB Magnets at the Canadian Light Source 4022
  • C.K. Baribeau, D. Bertwistle, L.O. Dallin, J.M. Vogt, W.A. Wurtz
    CLS, Saskatoon, Saskatchewan, Canada
  The BioXAS beamline at Canadian Light Source installed a hybrid wiggler in 2013. Quantitative studies building on the experience of other facilities suggest the wiggler's NdFeB magnets are at risk of demagnetization due to radiation induced by the synchrotron's 2.9 GeV electrons. We use a phenomenological model to convert simulated peak demagnetizing fields into a radiation dose corresponding to a chosen %-demagnetization, and compare against an estimated dose per year due to injected beam. We find that injecting with the wiggler closed will cause 1% demagnetization in sections of its magnet blocks within 2 years of operation, assuming a worst case scenario. The wiggler has thus far been forced open for injections, but this will cease to be an option when CLS moves to top-up operation. In a related test, qualitative measurements of radiation during injections with the wiggler closed were taken by covering its magnets in Polaroid film. We find that radiation drops significantly when the injection efficiency is well-tuned. Our results suggest the wiggler will not receive damaging levels of radiation at closed gap so long as the injection system remains optimized.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW036  
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THPOW037 Simulated and Measured Magnetic Performance of a Double APPLE-II Undulator at the Canadian Light Source 4025
  • C.K. Baribeau, L.O. Dallin, J.M. Helfrich, T.M. Pedersen, M.J. Sigrist, W.A. Wurtz
    CLS, Saskatoon, Saskatchewan, Canada
  Assembly and shimming are underway for a double APPLE-II type elliptically polarized undulator (i.e. two magnet arrays installed side by side on a single support structure) at the Canadian Light Source. The device is planned to be installed in spring 2017. Extensive preparation was done prior to device assembly, particularly in development of a simulated annealing algorithm for magnet virtual shimming, as well as assembly procedures that minimized positional errors in the installed magnet blocks. In this paper we present measurements taken throughout the shimming process, and compare with predictions from a RADIA model where each magnet block was magnetized uniquely according to individual Helmholtz coil measurements.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW037  
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