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Paper Title Other Keywords Page
THP006 704 MHz High Power Coupler and Cavity Development for High Power Pulsed Proton Linacs cavity, proton, linac, vacuum 786
  • G. Devanz, J.-P. Charrier, S. Chel, M. Desmons, Y. Gasser, A. Hamdi, P. Hardy, J. Plouin, D. Roudier
    CEA, Gif-sur-Yvette

In the framework of the European CARE-HIPPI program we develop components for superconducting high pulsed power proton linacs at 704 MHz. We have designed, fabricated and tested a beta 0.47 5-cell elliptical cavity with an optimized stiffening to reduce its sensitivity to Lorentz forces. A fast piezo tuner has been developed in order to be able to operate the cavity in pulsed mode in our horizontal test cryostat CryHoLab. We also have carried out the development of a fundamental power coupler. It is designed to transmit a power up to 1 MW at a 10% duty cycle. A high power test area has been setup consisting of a 1.2 MW klystron, a pulsed high voltage power supply and a coupler test stand.

THP012 Nondestructive Testing of Niobium Sheets for SRF Cavities Using Eddy-current and SQUID Flaw Detection niobium, cavity, controls, neutron 800
  • A. Brinkmann, W. Singer
    DESY, Hamburg

For more than 10 years DESY has been operating a high resolution eddy-current scanning installation with rotating table for nondestructive flaw detection on niobium sheets for SRF cavities. More than 2000 sheets have been examined up to now, several types of defects have been detected and identified using different supplementary methods such as EDX, X-ray fluorescence, neutron activation analysis etc. In order to scan Nb-sheets needed for XFEL-cavity production, new scanning devices have to be build. One option of the eddy-current installations could be an application of SQUID-sensors due to much higher sensitivity instead of conventional probes. A SQUID based scanner system was built and is in evaluation at DESY. A status report will be given.

THP013 Various Applications of Dry-Ice Cleaning in the Field of Accelerator Components at DESY cavity, gun, cathode, SRF 803
  • A. Brinkmann, D. Reschke, J. Ziegler
    DESY, Hamburg

Funding: We acknowledge the support of the European Community Research Infrastructure Activity under FP6 'Structuring the European Research Area' program (CARE, contract number RII-CT-2003-506395
Dry-Ice cleaning offers a dry and waterless cleaning option removing hydrocarbons and particles without residues. Complex excavations like Cu rf gun cavities and Nb multicell cavities in horizontal installation position can be cleaned in an effective way. In the recent past rf gun cathodes and cathode transportboxes could be cleaned satisfactory. A status report will be given.

THP014 Recent Results of 1.3 GHz Nine-Cell Superconducting Cavities for the European XFEL cavity, HOM, niobium, superconducting-cavity 806
  • L. Lilje, D. Reschke
    DESY, Hamburg

In preparation for the series production of roughly 800 superconducting accelerating structures, several tests with an industrial-like production sequence have been tested for their accelerating gradient and quality factor. The main part of the surface preparation is being done with electropolishing. with ethanol rinse. For the two different final preparation steps namely electropolishing and etching the performance is compared. The results will be also put into the perspective of earlier cavity production cycles that were tested at DESY.

THP016 Analysis of Quenches Using Temperature Mapping in 1.3 GHz SCRF Cavities at DESY cavity, superconducting-cavity, electron, synchrotron 812
  • D. Reschke
    DESY, Hamburg

The local thermal breakdown (quench) behavior of one- and nine-cell SCRF Nb accelerator cavities is investigated systematically. For more than 50 cavities, temperature mapping data have been analyzed with respect to surface preparation, Nb material etc. Results on quench location and characteristic correlations are presented.

THP029 Performance of 3.9-GHZ Superconducting Cavities cavity, HOM, status, SRF 848
  • E.R. Harms, H.T. Edwards, A. Hocker, T.N. Khabiboulline, N. Solyak
    Fermilab, Batavia

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
3.9 GHz SRF cavities have been built and tested at Fermilab for use in the DESY FLASH facility. Six cavities have undergone testing in various scenarios. Comparisons of performance in these different conditions, from bare cavities in a vertical dewar to 'dressed' in the horizontal test stand and intermediate test configurations are presented. We also report on analysis of expected maximum performance and an estimate of same.

THP033 Superconducting Quarter-Wave Resonator Cavity and Cryomodule Development for a Heavy Ion Re-accelerator cavity, cryomodule, solenoid, ion 854
  • W. Hartung, J. Bierwagen, S. Bricker, C. Compton, J. DeLauter, P. Glennon, M. Hodek, M.J. Johnson, F. Marti, P.S. Miller, D. Norton, J. Popielarski, L. Popielarski, D. Sanderson, J. Wlodarczak, R.C. York
    NSCL, East Lansing, Michigan
  • A. Facco
    INFN/LNL, Legnaro, Padova
  • E.N. Zaplatin
    FZJ, Jülich

A superconducting linac is being planned for re-acceleration of exotic ions produced by the Coupled Cyclotron Facility at Michigan State University. The re-accelerator will include a gas stopper, a charge breeder, a normal conducting radio-frequency quadrupole, and two types of superconducting quarter-wave resonators (QWRs) for re-acceleration to energies of up to 3 MeV per nucleon initially, with a subsequent upgrade path to 12 MeV per nucleon. The QWRs (80.5 MHz, optimum beta = 0.041 and 0.085, made from bulk niobium) are similar to existing cavities presently used at INFN-Legnaro. The re-accelerator's cryomodules will accommodate up to 8 cavities, along with superconducting solenoids for focussing. Active and passive shielding is required to ensure that the solenoids' field does not degrade the cavity performance. First prototypes of both QWR types have been fabricated and tested. A prototype solenoid has been procured and tested. A test cryomodule has been fabricated: one QWR, one solenoid, and two other beam line elements have been installed inside. This paper will cover the re-accelerator cavity and cryomodule prototyping efforts, results so far, and future plans.


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THP093 Power Coupler and Tuner Development for Superconducting Quarter-Wave Resonators vacuum, cavity, niobium, cryomodule 1005
  • J. Wlodarczak, P. Glennon, W. Hartung, M. Hodek, M.J. Johnson, D. Norton, J. Popielarski
    NSCL, East Lansing, Michigan

The construction of a reaccelerator for secondary ion beams is currently underway at the National Superconducting Cyclotron Laboratory (NSCL). The reaccelerator linac will use superconducting quarter-wave resonators (QWR) operating at 80.5 MHz with beta = 0.041 and beta = 0.085. A coaxial probe-type rf fundamental power coupler (FPC) will be used for both QWR types. The power coupler makes use of a commercially-available feedthrough to minimize the cost. The FPC has been simulated and optimized for operation at 80.5 MHz using a finite element electromagnetics code. Prototype FPC have been fabricated and conditioned with traveling wave and standing wave power using a 1 kW amplifier. A niobium tuning plate is incorporated into the bottom flange of the QWR. The tuner is actuated by a stepping motor for slow (coarse) tuning and a stacked piezoelectric element in series for fast (fine) tuning. A prototype tuner for the beta = 0.041 QWR has been tested on the cavity at room temperature. This paper will cover the design, fabrication, and testing of the prototype coupler and tuner.

FR204 The Higgs Boson Holy Grail of Particle Physics neutron, proton, coupling, vacuum 1125
  • N.S. Lockyer
    TRIUMF, Vancouver

A major focus of the linac community is to develop technology in support of the ILC project. The science motivation for the ILC will be presented with reference to the particle physics programs at Fermilab and the LHC.


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