Author: Ristori, L.
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.  
WEPPC056 Pressure Sensitivity Characterization of Superconducting Spoke Cavities 2339
  • D. Passarelli, M.H. Awida, I.V. Gonin, L. Ristori, V.P. Yakovlev
    Fermilab, Batavia, USA
  The following proposal illustrates a method to characterize the pressure sensitivity behavior of superconducting spoke cavities. This methodology relies on evaluating the variation of resonant frequency of a cavity by observing only the displacements at designed regions of the cavity. The proposed method permits a reduced computational burden and a systematic approach to achieve a minimum value of pressure sensitivity in a complex system of dressed cavity. This method has been used to characterize the superconducting spoke cavities typs−1 (SSR1), under development for Project X, and to design the helium containment vessel in such way to reduce the pressure sensitivity value to zero.  
WEPPC057 Design of SSR1 Single Spoke Resonators for PXIE 2342
  • L. Ristori, M.H. Awida, I.V. Gonin, M. Merio, D. Passarelli, V.P. Yakovlev
    Fermilab, Batavia, USA
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.
The Project X Injector Experiment (PXIE) at Fermilab contains one cryomodule of Single Spoke Resonators operating at 325 MHz with a geometrical beta of 0.2. Two prototypes have been tested successfully at high gradients in the Fermilab Vertical Test Stand (VTS). We have welded a Stainless Steel helium vessel on the first prototype and tested it in the spoke-dedicated Test Cryostat. With excellent results in hand, an order for ten bare resonators was placed with US industry. A new design for the helium vessel was developed for these resonators with the main goal of reducing the sensitivity of the resonator to variations of the helium pressure to meet the requirements of PXIE. A new tuner was developed despite the good results of the first prototype. The new design was inevitable due to the different behavior of the resonator in the new helium vessel. Other aspects were improved such as the maintainability of the tuner motor and piezoelectric actuators allowing their replacement from access ports on the cryomodule's vacuum vessel.
WEPPC058 Development at ANL of a Copper-brazed Joint for the Coupling of the Niobium Cavity End Wall to the Stainless Steel Helium Vessel in the Fermilab SSR1 Resonator 2345
  • L. Ristori
    Fermilab, Batavia, USA
  • W.F. Toter
    ANL, Argonne, USA
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.
In order to reduce the sensitivity of the Fermilab SSR1 resonator to helium pressure variations, it was concluded that the cavity and helium vessel end-walls needed to be structurally coupled by means of a transition ring. With the materials to be connected being Niobium and Stainless Steel, it was decided to utilize the same technology already developed for the cavity flanges which consists of a furnace-brazed joint utilizing oxygen-free electrolytic copper. Small-scale and full-scale annular samples have been constructed at Argonne National Laboratory and subject to tensile tests, thermal cycling and visual inspections to qualify the joint. The transition ring is electron-beam welded to the cavity and TIG welded to the helium vessel, the process is explained in detail.
WEPPD005 SSR1 Cryomodule Design PXIE 2504
  • T.H. Nicol, S. Cheban, M. Chen, S. Kazakov, F. McConologue, Y. Orlov, D. Passarelli, V. Poloubotko, O. Pronitchev, L. Ristori, I. Terechkine
    Fermilab, Batavia, USA
  Funding: U.S. Department of Energy
Fermilab is planning to design and build a Project X Injector Experiment (PXIE), a cw linac, as a means of validating the Project X concept, reducing technical risks, and obtaining experience in the design and operation of a superconducting proton linac. The overall facility will include an ion source, low and medium-energy beam transport sections, a radio frequency quadrupole, and two cryomodules containing superconducting cavities. One will contain nine half-wave resonators operating at 162.5 MHz and six superconducting solenoids. The second will contain eight single spoke resonators (SSR1) operating at 325 MHz and four superconducting solenoids. This paper describes the design of the cryomodule being developed to house the 325 MHz single spoke resonators. Each of the main cryomodule systems will be described; cryogenic systems and instrumentation, cavity and solenoid positioning and alignment, conduction-cooled current leads, RF input couplers, magnetic shielding, cold-to-warm beam tube transitions, interfaces to interconnecting equipment and adjacent modules, as well as the overall assembly procedure.
THPPP062 The Six-Cavity Test - Demonstrated Acceleration of Beam with Multiple RF Cavities and a Single Klystron 3877
  • J. Steimel, J.-P. Carneiro, B. Chase, S. Chaurize, E. Cullerton, B.M. Hanna, R.L. Madrak, R.J. Pasquinelli, L.R. Prost, L. Ristori, V.E. Scarpine, P. Varghese, R.C. Webber, D. Wildman
    Fermilab, Batavia, USA
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The High Intensity Neutrino Source (HINS) ‘Six-Cavity Test’ has demonstrated the use of high power RF vector modulators to control multiple RF cavities driven by a single high power klystron to accelerate a non-relativistic beam. Installation of 6 cavities in the existing HINS beamline has been completed and beam measurements have started. We present data showing the energy stability of the 7 mA proton beam accelerated through the six cavities from 2.5 MeV to 3.4 MeV.