Author: Popielarski, J.
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]  
WEPPC065 Cleanroom Techniques to Improve Surface Cleanliness and Repeatability for SRF Coldmass Production 2357
  • L. Popielarski, L.J. Dubbs, K. Elliott, I.M. Malloch, R. Oweiss, J. Popielarski
    FRIB, East Lansing, USA
  Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University.
The Facility for Rare Isotope Beams (FRIB) and ReA linear accelerator projects at Michigan State University (MSU) utilize Superconducting Radio-Frequency (SRF) cavities for their accelerating structures. The structures are cleaned and assembled in a cleanroom to reduce particle contamination. The project requires more than 350 SRF cavities. In preparation for production we want to maximize repeatable processes and reduce work time. The cleanroom assembly group at MSU investigates process techniques performed in the cleanroom. Various diagnostic tools; such as liquid particle counter, surface particle counter and airborne particle counter are used to quantify environments and optimize processes. We desire to define procedure specifications for cleaner processes and repeatability. We investigate effective part cleaning and storage, high pressure rinse and ultra pure water quality, and critical component rinsing. We study vacuum assembly, pump down and purge effects. The experiments are independent of cavity results with a focus to create cleanest surface and environment in the most effective manner. In this paper, we describe experiments, summarize the results and conclusions.
WEPPC067 Dewar Testing of Coaxial Resonators at MSU 2363
  • J. Popielarski, E.C. Bernard, A. Facco, M. Hodek, F. Marti, D. Norton, G.J. Velianoff, J. Wlodarczak
    FRIB, East Lansing, Michigan, USA
  • A. Burrill, G.K. Davis
    JLAB, Newport News, Virginia, USA
  Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University
Michigan State University is currently testing prototype and production cavities for two accelerator projects. 80.5 MHz β=0.085 quarter wave resonators (QWR) are being produced as part of a cryomodule for ReA3. 322 MHz β=0.53 half wave resonators (HWR) are being prototyped for a driver linac for the Facility for Rare Isotope Beams. This paper will discuss test results and how different cavity preparations effect cavity performs. Also various diagnostics methods have been developed, such as second sound quench location determination, and temperature mapping to determine hot spots from defects and multipacting location.
WEPPC068 Multipacting Simulation and Analysis for the FRIB β = 0.085 Quarter Wave Resonators using Track3P 2366
  • L. Ge, C. Ko, Z. Li
    SLAC, Menlo Park, California, USA
  • J. Popielarski
    FRIB, East Lansing, Michigan, USA
  Funding: Work supported by DOE Office of Science under Cooperative Agreement DE- SC0000661, DOE Contract No. DE-AC02-76SF00515, and used resources of NERSC supported by DOE Contract No. DE-AC02- 05CH11231.
The drive linac for the Facility for Rare Isotope Beams (FRIB) utilizes several types of low beta superconducting resonators to accelerate the ion beams from 0.3 MeV per nucleon to 200 MeV per nucleon. Multipacting is an issue of concern for such superconducting resonators as they have unconventional shapes. We have used the parallel codes Tack3P and Omega3P, developed at SLAC under the support of the DOE SciDAC program, to analyze the multipacting barriers of such resonators. In this paper, we will present the simulation results for the β(v/c) = 0.085 Quarter Wave Resonator (QWR) for the FRIB project. Experimental data will also be presented to benchmark with the simulation results.