Author: Hartung, W.
Paper Title Page
FROBN2 Technical Challenges in Design and Construction of FRIB 2561
 
  • R.C. York, G. Machicoane
    NSCL, East Lansing, Michigan, USA
  • S. Assadi, G. Bollen, T . Glasmacher, W. Hartung, M.J. Johnson, F. Marti, E. Pozdeyev, M.J. Syphers, E. Tanke, J. Wei, X. Wu, Q. Zhao
    FRIB, East Lansing, Michigan, USA
  
  Funding: Work supported by DOE CA DE-SC0000661 and Michigan State University.
The Facility for Rare Isotope Beams (FRIB) will be a world-leading, DOE national users facility for the study of nuclear structure, reactions and astrophysics on the campus of Michigan State University. A superconducting, heavy-ion, driver linac will be used to provide stable beams of >200 MeV/u at beam powers up to 400 kW (~650 electrical micro-amps for uranium) that will be used to produce rare isotopes by in flight fragment separation. The selected rare isotopes will be used at velocity (~0.5 c), stopped, or reaccelerated. FRIB is a challenging technical project. An overview of the project, project challenges, and mitigating strategies will be presented. 		 
slides icon Slides FROBN2 [14.690 MB]  
 
TUP090 Design of a β = 0.29 Half-wave Resonator for the FRIB Driver Linac 997
 
  • J.P. Holzbauer, W. Hartung, J. Popielarski
    NSCL, East Lansing, Michigan, USA
  
  The driver linac for the Facility for Rare Isotope Beams will produce primary beams of ions at 200 MeV per nucleon for nuclear physics research. The driver linac will require 344 superconducting cavities, consisting of two types of Quarter-Wave Resonators (QWRs, β = 0.041 and 0.085) and two types of Half-Wave Resonators (HWRs, β = 0.29 and 0.53). A first-generation β = 0.29 HWR has been designed, prototyped, and tested. Second-generation versions of the other cavities are being developed, with one or more prototype having been tested. A second-generation β = 0.29 HWR design has been developed, making use of the experience with the first-generation β = 0.29 HWR and second-generation β = 0.53 HWR. In the second-generation design, the inner conductor is tapered to reduce the peak surface magnetic field. The outer conductor is a straight tube to increase the mechanical stiffness and reduce the sensitivity of the resonant frequency to bath pressure fluctuations. Optimization was employed to minimize the peak surface electric field. The second-generation β = 0.29 HWR design will be presented, including the RF design and mechanical analysis.  
 
TUP091 Electromagnetic Design of a Multi-harmonic Buncher for the FRIB Driver Linac 1000
 
  • J.P. Holzbauer, W. Hartung, F. Marti, Q. Zhao
    NSCL, East Lansing, Michigan, USA
  • E. Pozdeyev
    FRIB, East Lansing, Michigan, USA
  
  Funding: Work supported by the U.S. Department of Energy under Grant Number DE-FGO2-08ER41553.
The driver linac for the Facility for Rare Isotope Beams (FRIB) at MSU will produce primary beams of ions at ≥200 MeV/u for nuclear physics research. A dc ion beam from an ECR ion source will be pre-bunched upstream of the radio frequency quadrupole linac. A multi-harmonic buncher (MHB) was designed for this purpose, using experience gained with a similar buncher for the ReA3 re-accelerator linac, which is presently being commissioned at MSU. The FRIB MHB resonator operates with three frequencies (40.25 MHz, 80.5 MHz, and 120.75 MHz) to produce an approximately linear sawtooth in the voltage as a function of time. The three resonant frequencies are produced via two quarter-wave resonators with a common gridless gap: one resonator is driven at its fundamental mode at 40.25 MHz and its first higher-order mode (120.75 MHz), while the other is driven only at its fundamental mode of 80.5 MHz. The electromagnetic design of the MHB resonator will be presented, including the electrode design and tuning mechanisms.