• V.S. Kashikhin, E. Borissov, G.W. Foster, T.N. Khabiboulline, A. Makulski, Y.M. Pischalnikov
  Fermilab, Batavia

Funding: Department of Energy, U.S.A.

A novel prototype of SCRF cavity tuner is being designed and tested at Fermilab. This is a superconducting C-type iron dominated magnet having a 10 mm gap, axial symmetry, and a 1 Tesla field. Inside the gap is mounted a superconducting coil capable of moving ± 1 mm and producing a longitudinal force up to ± 1.5 kN. The static force applied to the RF cavity flanges provides a long- term cavity geometry tuning to a nominal frequency. The same coil powered by a fast AC current pulse delivers mechanical perturbation for fast cavity tuning. This fast mechanical perturbation could be used to compensate a dynamic RF cavity detuning caused by cavity Lorentz forces and microphonics. A special configuration of magnet system was designed and tested.

• R.H. Carcagno, T.N. Khabiboulline, S. Kotelnikov, A. Makulski, R. Nehring, J.M. Nogiec, M.C. Ross, W. Schappert
  Fermilab, Batavia
• A. Goessel, J. Iversen, D. Klinke, G. Kreps, W.-D. Möller, C. Mueller, D. Proch, J.H. Thie
  DESY, Hamburg

A series of four automatic tuning machines for 9-cell TESLA-type cavities are being developed and fabricated through a collaboration between DESY, FNAL and KEK. These machines are intended to support high-throughput cavity fabrication for construction of large SRF-based accelerator projects. Two of these machines will be delivered to cavity vendors for the tuning of XFEL cavities. The control system for these machines must support a high level of automation adequate for industrial use by non-expert operators. This paper describes the control system hardware and software designs, and shows preliminary results obtained with a tuning machine prototype.

• H.T. Edwards, T.T. Arkan, M.H. Foley, M. Ge, E.R. Harms, A. Hocker, T.N. Khabiboulline, M.W. McGee, D.V. Mitchell, D.R. Olis, A.M. Rowe, N. Solyak
  Fermilab, Batavia

Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.

Fermilab is in a collaboration with DESY to provide a cryomodule containing 4-3.9 GHz superconducting RF cavities to be placed in TTF/FLASH. The purpose of this 'Third Harmonic' module is to linearize the nonlinear beam energy-time profile produced by the 1.3 GHz accelerating gradient. The completed module has now been shipped to DESY and is awaiting cold, powered testing and installation into FLASH later this year. We report on experience with fabricating, testing, assembling, and shipping the module and its components with a focus on cavity test results.

• L. Ristori, G. Apollinari, I.G. Gonin, T.N. Khabiboulline, A. Mukherjee, J.P. Ozelis, D.A. Sergatskov, R.L. Wagner, R.C. Webber
  Fermilab, Batavia

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359

The Fermilab High Intensity Neutrino Source (HINS) Linac R&D program is building a 60 MeV superconducting H^- linac. The Linac incorporates SC solenoids, high power RF vector modulators and SC spoke-type accelerating cavities starting at 10 MeV. This will be the first application and demonstration of any of these technologies in a low-energy, high-intensity proton/H^- linac. The HINS effort is relevant to a high intensity, SC H^- linac that might serve the next generation of neutrino physics and muon storage ring/collider experiments. Three types of superconducting resonators are used in the linac front end. Single Spoke Resonators typs^-1 (SSR1) at Beta=0.2, Single Spoke Resonators type-2 (SSR2) at Beta=0.4 and Triple Spoke Resonators (TSR) at Beta=0.6. In this paper we describe the Buffer Chemical Polishing (BCP) performed on SSR1-#2 and the results of the cold tests for this bare cavity. We also describe the inelastic tune performed on cavity SSR1-#1, during this operation we measured also the spring constant and the frequency sensitivity of the end walls. We have also completed the design for the helium vessel that will be used to jacket SSR1 resonators and we present its design here.

• V.P. Yakovlev, I.G. Gonin, T.N. Khabiboulline, A. Latina, A. Lunin, V. Poloubotko, N. Solyak
  Fermilab, Batavia

Different couplers are described that allow the reduction of both transverse wake potential and RF kick in the SC acceleration structure of ILC. A simple rotation of the couplers reducing the RF kick and transverse wake kick is discussed for both the main linac and bunch compressors, along with possible limitations of this method. Designs of a coupler unit are presented which preserve axial symmetry of the structure, and provide reduced both the RF kick and transverse wake field.

• V.P. Yakovlev, I.G. Gonin, T.N. Khabiboulline, N. Solyak
  Fermilab, Batavia

In the paper the Crab Cavity is described for local Crab schemes for LHC that demand reduced transverse cavity dimensions small enough to fit limited space necessary for the beams separation. The results of the configuration cavity optimization are presented that include (a) the surface field minimization; (b) parasitic monopole and dipole spectrum optimization and dumping, (c) the input and the parasitic mode damping couplers design. The results of multipacting simulations, which were performed in order to understand the possible gradient limitations, are discussed also.