Author: Kitegi, C.A.
Paper Title Page
TUPAB140 Analysis and Correction of in-Vacuum Undulator Misalignment Effects in a Storage Ring Synchrotron Radiation Source 1663
 
  • O.V. Chubar, T.A. Caswell, Y. Chen-Wiegart, A. Fluerasu, Y. Hidaka, D.A. Hidas, C.A. Kitegi, M.S. Rakitin, T. Tanabe, J. Thieme, L. Wiegart, G. Williams
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work was partially supported by US DOE SBIR grants DE-SC0006284 and DE-SC0011237.
In-vacuum undulators (IVU) are currently very extensively used at different light source facilities, and in particular in medium-energy storage rings, for the production of high-brightness and high-flux hard X-rays. The relatively small (~5 mm or less) vertical magnetic gaps used in these planar undulators make them, however, rather sensitive to the accuracy of alignment of magnet arrays with respect to electron orbit in the vertical plane. Based on results of commissioning of a number of IVUs at hard X-ray beamlines of NSLS-II, their eventual misalignment with respect to the electron orbit was found to be among frequent reasons of spectral underperformance of the beamlines. We will present results of simulations of different IVU misalignment effects on magnetic fields seen by electron beam and on the emitted undulator radiation spectra. The simulations show e.g. that an impact of angular misalignment of an IVU on the radiation spectrum can be minimized if the IVU elevation is selected to make the electron orbit to pass through the IVU magnetic center. Experimental results of spectrum-based alignment of IVUs at hard X-ray beamlines will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB140  
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TUOAA3 Progress of Pr2Fe14B Based Hybrid Cryogenic Undulators at SOLEIL 1213
SUSPSIK023   use link to see paper's listing under its alternate paper code  
 
  • A.M. Ghaith, P. Berteaud, F. Blache, F. Briquez, N. Béchu, M.-E. Couprie, J. Da Silva Castro, J.M. Dubuisson, C. Herbeaux, C.A. Kitegi, A. Lestrade, O. Marcouillé, F. Marteau, M. Sebdaoui, G. Sharma, A. Somogyi, K.T. Tavakoli, M. Tilmont, M. Valléau
    SOLEIL, Gif-sur-Yvette, France
  • C. Benabderrahmane
    ESRF, Grenoble, France
 
  Cryogenic Permanent Magnet Undulators (CPMUs) take advantage of the enhanced field performance of permanent magnets when cooled down to low temperature, enabling shorter period with sufficient magnetic field to achieve high brightness radiation in the X-ray domain. Several CPMUs have been manufactured at SOLEIL. The first CPMU of period 18 mm (U18), optimized with a phase error of 3.2° at temperature of 77 K, has been installed and operated for the past 5 years at SOLEIL for the NANOSCOPIUM beamline. We report on photon beam based alignment enabling for a better adjustment of the vertical position offset of the undulator with a precision of 50 μm, and on the correction of the taper with a precision of 5 μrad to enhance the radiation flux. A second U18 cryo-ready undulator, with a new mechanical and magnetic sorting of module shimming, has attained a phase error of 2.3° at CT without any further adjustments after the assembly. Currently, two more CPMUs are being built; a 2 m long U18 for the SOLEIL ANATOMIX beamline, and a 3 m long U15 undulator reaching a magnetic gap of 3 mm. The new challenges encountered with magnetic measurements and mechanical designs for U15 are presented.  
slides icon Slides TUOAA3 [3.491 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUOAA3  
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