Author: Zheng, Z.
Paper Title Page
MOOAC03 Superconducting Resonators Development for the FRIB and ReA Linacs at MSU: Recent Achievements and Future Goals 61
 
  • A. Facco
    INFN/LNL, Legnaro (PD), Italy
  • E.C. Bernard, J. Binkowski, C. Compton, J.L. Crisp, L.J. Dubbs, K. Elliott, A. Facco, L.L. Harle, M. Hodek, M.J. Johnson, D. Leitner, M. Leitner, I.M. Malloch, S.J. Miller, R. Oweiss, J. Popielarski, L. Popielarski, K. Saito, J. Wei, J. Wlodarczak, Y. Xu, Y. Zhang, Z. Zheng
    FRIB, East Lansing, Michigan, USA
  • A. Burrill, G.K. Davis, K. Macha, A.V. Reilly
    JLAB, Newport News, Virginia, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The superconducting driver and post-accelerator linacs of the FRIB project, the large scale radioactive beam facility under construction at MSU, require the construction of about 400 low-beta Quarter-wave (QWR) and Half-wave resonators (HWR) with four different optimum velocities. 1st and 2nd generation prototypes of β=0.041 and 0.085 QWRs and β=0.53 HWRs have been built and tested, and have more than fulfilled the FRIB and ReA design goals. The present cavity surface preparation at MSU allowed production of low-beta cavities nearly free from field emission. The first two cryostats of β=0.041 QWRs are now in operation in the ReA3 linac. A 3rd generation design of the FRIB resonators allowed to further improve the cavity parameters, reducing the peak magnetic field in operation and increasing the possible operation gradient , with consequent reduction of the number of required resonators. The construction of the cavities for FRIB, which includes three phases for each cavity type (development, pre-production and production runs) has started. Cavity design, construction, treatment and performance will be described and discussed.
Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.
 
slides icon Slides MOOAC03 [4.009 MB]  
 
TUPPC011 Beam Steering Correction in FRIB Quarter-wave Resonators 1176
 
  • A. Facco
    INFN/LNL, Legnaro (PD), Italy
  • A. Facco, Y. Xu, Y. Zhang, Q. Zhao, Z. Zheng
    FRIB, East Lansing, Michigan, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The Quarter-Wave Resonators (QWR) section of the FRIB superconducting driver linac is required to accelerate Uranium beam up to 16 MeV/u in two different charge states simultaneously. This puts severe requirements on resonators alignment and field quality, in order to avoid beam losses and emittance growth. In particular, QWR beam steering can cause transverse oscillations of the beam centroid which reduce the linac acceptance and induces emittance growth. We have studied, with an analytical model and with 3D beam dynamics simulations, correction methods for the FRIB QWRs steering. We found that cavity shifting can provide effective steering cancellation in FRIB QWRs without need of cavity shape modifications, and allows to eliminate transverse beam oscillations and to improve beam quality. Calculation and simulation methods and results will be presented and discussed.
Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.