Author: Ozelis, J.P.
Paper Title Page
WEPPC052 High Gradient Tests of the Fermilab SSR1 Cavity 2330
  • T.N. Khabiboulline, C.M. Ginsburg, I.V. Gonin, R.L. Madrak, O.S. Melnychuk, J.P. Ozelis, Y.M. Pischalnikov, L. Ristori, A.M. Rowe, D.A. Sergatskov, A.I. Sukhanov, I. Terechkine, R.L. Wagner, R.C. Webber, V.P. Yakovlev
    Fermilab, Batavia, USA
  In Fermilab we are build and tested several superconducting Single Spoke Resonators (SSR1, β=0.22) which can be used for acceleration of low beta ions. Fist two cavities performed very well during cold test in Vertical Test Station at FNAL. One dressed cavity was also tested successfully in Horizontal Test Station. Currently we are building 8 cavity cryomodule for PIXIE project. Additional 10 cavities were manufactured in the industry and ongoing cold test results will be presented in this poster.  
WEPPC116 Depth Distribution of Losses in Superconducting Niobium Cavities 2495
  • A. Romanenko, A. Grassellino, J.P. Ozelis
    Fermilab, Batavia, USA
  • H. Padamsee
    CLASSE, Ithaca, New York, USA
  In order to optimize performances of superconducting niobium cavities it is crucial to understand the structure of near-surface few tens of nanometers of the material. In particular, superconducting properties of niobium, which depend on the presence of impurities and/or defects, may be non-uniform in the magnetic field penetration depth. A few cavity experiments based on oxypolishing* and anodizing**,*** provided some insight into the problem, but the definitive understanding is not developed yet. In this contribution we report on the "depth profiling" of the near-surface RF layer using an alternative technique based on the hydrofluoric acid (HF) rinsing. Tumbled, electropolished and buffered chemical polished cavities have been investigated and tentative nanostructural interpretation is discussed.
* P. Kneisel, Proc. of the 1999 SRF Workshop, Santa Fe, USA
** G. Eremeev and H. Padamsee, Physica C 441 No. 1-2 (2006) 62
*** G. Ciovati, P. Kneisel and A. Gurevich, PRSTAB 10 (2007) 062002
WEPPC049 Individual RF Test Results of the Cavities Used in the First US-built ILC-type Cryomodule 2321
  • A. Hocker, A.C. Crawford, E.R. Harms, A. Lunin, D.A. Sergatskov, A.I. Sukhanov
    Fermilab, Batavia, USA
  • G.V. Eremeev, R.L. Geng
    JLAB, Newport News, Virginia, USA
  • J.P. Ozelis
    FRIB, East Lansing, USA
  Funding: Work supported in part by the U.S. Department of Energy under Contract No. DE-AC02-07CH11359.
Eight 1.3-GHz, nine-cell SRF cavities have been installed in a cryomodule intended to demonstrate the ILC design goal of 31.5 MV/m. These cavities all underwent two types of individual RF testing: a low-power continuous-wave test of the “bare” cavity and a high-power pulsed test of the “dressed” cavity. Presented here is a discussion of the results from these tests and a comparison of their performance in the two configurations.
WEPPD006 Design of the FRIB Cryomodule 2507
  • M.J. Johnson, M. Barrios, J. Binkowski, S. Bricker, F. Casagrande, A.D. Fox, B.R. Lang, M. Leitner, S.J. Miller, T. Nellis, J.P. Ozelis, X. Rao, J. Weisend, Y. Xu
    FRIB, East Lansing, Michigan, USA
  • D. Arenius, V. Ganni, W.J. Schneider, M. Wiseman
    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
An advanced, modular bottom-supported cryomodule design is described which is highly optimized for mass-production and efficient precision-assembly. The FRIB driver linac uses 4 types of superconducting resonators and 2 solenoid lengths which in turn require 7 individual cryomodule configurations. To meet alignment tolerances a precision-machined bolted cryomodule rail system is described. A novel, kinematic mounting system of the cold mass is introduced which allows for thermal contractions while preserving alignment. A first prototype will incorporate a wire position monitor for alignment verification. The cold alignment structure is supported by composite posts which also function as thermal isolators. The cryogenic system provides separate 2 K and 4.5 K liquid helium lines to cavities and solenoids. Details of the JT valves, heat exchanger, cool-down circuit and junction to cryogenic line will be provided. Transient cool-down was simulated for stresses and buckling failure. A 1100-O Aluminum shield is used as a thermal radiation shield. The paper also describes cryomodule interfaces with the linac tunnel, the RF input cables, and the cryogenic distribution system.
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.