Author: Zheng, Z.
Paper Title Page
MOPAB35 Beam Dynamics Influence from Quadrupole Components in FRIB Quarter Wave Resonators 108
 
  • Z.Q. He, Z. Liu, J. Wei, Y. Zhang, Z. Zheng
    FRIB, East Lansing, Michigan, USA
  
  Funding: The work is supported by the U.S. National Science Foundation under Grant No. PHY-11-02511, and the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
Non-ax­isym­met­ric RF cav­i­ties, such as quar­ter-wave res­onators (QWRs), can pro­duce ax­i­ally asym­met­ric mul­ti­pole field com­po­nents that can in­flu­ence beam dy­nam­ics. For ex­am­ple, di­pole com­po­nents can cause beam steer­ing, an ef­fect that has been well known to the com­mu­nity since 2001. How­ever, higher order mul­ti­pole field com­po­nents, such as quadru­pole com­po­nents, which have po­ten­tial in­flu­ence on beam dy­nam­ics, have never re­ceived enough at­ten­tion yet. In this paper, we choose FRIB QWRs as an ex­am­ple and quadru­pole com­po­nents are ex­tracted by mul­ti­pole ex­pan­sion. Then, in­flu­ence of quadru­pole com­po­nents on a sin­gle cav­ity is stud­ied using thin lens model. After that, the in­flu­ence of quadru­pole com­po­nents on a whole FRIB linac seg­ment one is stud­ied, and ef­fects such as trans­verse pro­file oval­iza­tion and blow up of beam size are wit­nessed. Lastly, a pos­si­ble way of quadru­pole com­po­nents com­pen­sa­tion for FRIB dri­ving linac is dis­cussed.