Author: Yakovlev, V.P.
Paper Title Page
MOP145 Physics Design of the Project X CW Linac 364
 
  • N. Solyak, J.-P. Carneiro, J.S. Kerby, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, A. Saini, A. Vostrikov, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  The general design of the 3 GeV superconducting CW linac of the Project X is presented. Different physical and technical issues and limitations that determine the linac concept are discussed. The results of the RF system optimization are presented as well as the lattice design and beam dynamics analysis.  
 
TUP015 Conceptual Design of the Project-X 1.3 GHz, 3-8 GeV Pulsed Linac 841
 
  • N. Solyak, Y.I. Eidelman, S. Nagaitsev, J.-F. Ostiguy, A. Vostrikov, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  The Project-X, a multi-MW proton source, is under development at Fermilab. It enables a Long Baseline Neutrino Experiment via a new beam line pointed to DUSEL in Lead, South Dakota, and a broad suite of rare decay experiments. The facility contains 3-GeV 1-mA CW superconducting linac. In the second stage of about 5% of the H beam is accelerated up to 8 GeV in a 1.3 GHz SRF pulse linac to Recycler/Main Injector. In order to mitigate the problem with the stripping foil heating during injection to the Main Injector, the pulses with higher current are accelerated in CW linac together with 1 mA beam for further acceleration in the pulse linac. The optimal current in the pulse linac is discussed as well as limitations that determine it's selection. A concept design of the pulse linac is described. The lattice design is presented as well as RF stability analysis. The necessity of the HOM couplers is discussed also.  
 
TUP066 Three-cell Traveling-wave Superconducting Test Structure 940
 
  • P.V. Avrakhov, A. Kanareykin
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • S. Kazakov, N. Solyak, G. Wu, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Use of a superconducting traveling wave accelerating (STWA) structure* with a small phase advance per cell rather than a standing wave structure may provide a significant increase of the accelerating gradient in the ILC linac. For the same surface electric and magnetic fields the STWA achieves an accelerating gradient 1.2 larger than TESLA-like standing wave cavities. The STWA allows also longer acceleration cavities, reducing the number of gaps between them. However, the STWA structure requires a SC feedback waveguide to return the few hundreds of MW of circulating RF power from the structure output to the structure input. A test single-cell cavity with feedback was designed, manufactured and successfully tested** demonstrating the possibility of a proper processing to achieve a high accelerating gradient. These results open the way to take the next step of the TW SC cavity development: to build and test a traveling-wave three-cell cavity with a feedback waveguide. The latest results of the single-cell cavity tests are discussed as well as the design of the test 3-cell TW cavity.
* P. Avrakhov, et al, Phys. of Part. and Nucl. Let, 2008, Vol. 5, No. 7, p. 597
** G. Wu, et al, IPAC 2010, THPD048
 
 
TUP069 Status of the Mechanical Design of the 650 MHz Cavities for Project X 943
 
  • S. Barbanotti, M.S. Champion, M.H. Foley, C.M. Ginsburg, I.G. Gonin, C.J. Grimm, T.J. Peterson, L. Ristori, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  In the high-energy section of the Project X Linac, acceleration of H- ions takes place in superconducting cavities operating at 650 MHz. Two families of five-cell elliptical cavities are planned: β = 0.61 and β = 0.9. A specific feature of the Project X Linac is low beam loading, and thus, low bandwidth and higher sensitivity to microphonics. Efforts to optimize the mechanical design of the cavities to improve their mechanical stability in response to the helium bath pressure fluctuations will be presented. These efforts take into account constraints such as cost and ease of fabrication. Also discussed will be the overall design status of the cavities and their helium jackets.  
 
TUP070 EM Design of the Low-Beta SC Cavities for the Project X Front End 946
 
  • I.G. Gonin, S. Barbanotti, P. Berrutti, L. Ristori, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  The low-energy part of the Project X H-linac includes three types of superconducting single spoke cavities (SSR) with β = 0.11, 0.21 and 0.4 operating at the fundamental TEM-mode at 325MHz. In this paper we present the detailed EM optimization of cavity shapes having the goal to minimize the peak electric and magnetic fields. We also discuss the importance of the integration of EM and mechanical design.  
 
TUP072 High Power Couplers for Project X Linac 952
 
  • S. Kazakov, M.S. Champion, M. Kramp, Y. Orlov, O. Pronitchev, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Project X, a multi-megawatt proton sources is under development in Fermi National Accelerator Laboratory. The key element of the project is a superconducting (SC) 3GV CW proton liner accelerator (linac). The linac includes 5 types of SC accelerating cavities of three 325 and 650 MHz frequencies. The cavities consumes up to 30 kW average RF power and need proper main couplers. Requirements and approach to the coupler design are discussed in the report. New cost effective schemes of the couplers are described. Results of electrodynamics and thermal simulations are presented.  
 
TUP073 Development of an L-band Ferroelectric Phase Shifter 955
 
  • S. Kazakov, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
  • J.L. Hirshfield
    Yale University, Physics Department, New Haven, CT, USA
  • A. Kanareykin, E. Nenasheva
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • S.V. Shchelkunov
    Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
 
  Effective operation of the RF cavities in the superconducting accelerators demands fast, high-power RF vector modulators. Recent progress in development of the new materials, ferroelectrics, having tunable dielectric constant and acceptable losses [*] gives the possibility development of such devises. In previous papers [**-***] the authors described different L-band ferroelectric phase shifter designs . At low RF level high operation speed of 2 degree/nsec was demonstrated in waveguide phase shifter. However, the experiments show that a special technology is to be developed that provides a good electric contact between ceramics and the metallic wall. In present paper a new design of the fast high–power ferroelectric phase shifter is described based on the simple ferroelectric elements.
* A. Kanareykin, et al, IPAC 2010, p. 3987
** S. Kazakov, et al, “Fast Ferroelectric Phase Shifter Design For ERLs,” 45th ICFA Beam Dynamics Workshop, 2009
*** S. Kazakov, et al, PAC2007, p. 599.
 
 
TUP074 Experiments on HOM Spectrum Manipulation in a 1.3 GHz ILC SC Cavity 958
 
  • T.N. Khabiboulline, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Superconducting cavities with high operating Q will be installed in the Project-X, a superconducting linac, which is under development at Fermilab. Possibility of cavity design without HOM couplers considered. Rich spectrum of the beam and large number of cavities in ProjectX linac can result to resonance excitation of some high order modes with high shunt impedance. Under scope of study of High Order Modes (HOM) damping the manipulation with HOM spectrum in cold linac is considered. Results of detuning HOM spectrum of 1.3 GHz cavities at 2K in Horizontal Test Station of Fermilab are presented. Possible explanation of the phenomena is discussed.  
 
TUP075 Cavity Loss Factors of Non-relativistic Beams for Project X 961
 
  • A. Lunin, S. Kazakov, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Cavity loss factor calculation is an important part of total cryolosses estimation for the super conductive (SC) accelerating structures. There are two approaches how to calculate cavity loss factors, the integration of a wake potential over the bunch profile and the combining of loss factors for individual cavity modes. We applied both methods in order to get reliable results for non-relativistic beam. The time domain CST solver was used for a wake potential calculation and the frequency domain HFSS code was used for the cavity eigenmodes spectrum findings. Finally we present the results of cavity loss factors simulations for a non-relativistic part of the ProjectX and analyze it for various beam parameters.  
 
TUP084 Design of Single Spoke Resonators for Project X 982
 
  • L. Ristori, S. Barbanotti, M.S. Champion, M.H. Foley, I.G. Gonin, C.J. Grimm, T.N. Khabiboulline, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Project X is based on a 3 GeV CW superconducting linac and is currently in the R&D phase awaiting CD-0 approval. The low-energy section of the Project X H-linac includes three types of super-conducting single spoke cavities operating at 325 MHz. SSR0 (26 cavities), SSR1 (18 cavities) and SSR2 (44 cavities) have a geometrical beta of = 0.11, 0.21 and 0.4 respectively. Single spoke cavities were selected for the linac in virtue of their higher r/Q. In this paper we present the decisions and analyses that lead to the final designs. Electro-magnetic and mechanical finite element analyses were performed with the purpose of optimizing the electro-magnetic design, minimizing frequency shifts due to Helium bath pressure fluctuations and providing a pressure rating for the resonators that allow their use in the cryomodules.  
 
TUP085 Assumptions for the RF Losses in the 650 MHz Cavities of the Project X Linac 985
 
  • A. Romanenko, L.D. Cooley, J.P. Ozelis, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  The requirements for the FNAL Project X cryogenic system depend on the dynamic heat loads of 650 MHz cavities. The heat load is in turn determined by quality factors of the cavities at the operating gradient. In this contribution we use the available experimental data to analyze quality factors achievable in 650 MHz linac cavities taking into account different RF losses contributions such as BCS resistance, residual resistance and a medium field Q-slope.  
 
TUP088 Resonance Effects of Longitudinal HOMs in Project X Linac 991
 
  • V.P. Yakovlev, I.G. Gonin, T.N. Khabiboulline, A. Lunin, N. Solyak, A.I. Sukhanov, A. Vostrikov
    Fermilab, Batavia, USA
  • A. Saini
    University of Delhi, Delhi, India
 
  High-order mode influence on the beam longitudinal and transverse dynamics is considered for the 650 MHz section of the Project X linac. RF losses caused by HOMs are analyzed. Necessity of HOM dampers in the SC cavities of the linac is discussed.  
 
TUP089 Concept EM Design of the 650 MHz Cavities for the Project X 994
 
  • V.P. Yakovlev, M.S. Champion, I.G. Gonin, T.N. Khabiboulline, A. Lunin, N. Solyak
    Fermilab, Batavia, USA
  • A. Saini
    University of Delhi, Delhi, India
 
  Concept of the 650 MHz cavities for the Project X is presented. Choice of the basic parameters, i.e, number of cells, geometrical β, apertures, coupling coefficients, etc, is discussed. The cavities optimization criteria are formulated. Results of the RF design are presented for the cavities of both low-energy and high energy sections.  
 
WEP006 Study of Effects of Failure of Beamline Elements & Their Compensation in CW Superconducting Linac 1513
 
  • A. Saini, K. Ranjan
    University of Delhi, Delhi, India
  • C.S. Mishra, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Project-X is the proposed high intensity proton facility to be built at Fermilab, US. The first stage of the Project-X consists of superconducting Linac which will be operated in continuous wave (CW) mode to accelerate the beam from 2.5 MeV to 3 GeV. The operation at CW mode puts high tolerances on the beam line components, particularly on radiofrequency (RF) cavity. The failure of beam line elements at low energy is very critical as it results in mis-match of the beam with the following sections due to different beam parameters than designed parameter. It makes the beam unstable which causes emittance dilution, and ultimately results in beam losses. In worst case, it could affect the reliability of the machine and may lead to the shutdown of the Linac to replace the failed elements. Thus, it is important to study these effects and their compensation to get smooth beam propagation in Linac. This paper describes the results of study performed for the failure of RF cavity & solenoid in SSR0 section.  
 
WEP007 Calculation of Acceptance of High Intensity Superconducting Proton Linac for Project-X 1516
 
  • A. Saini, K. Ranjan
    University of Delhi, Delhi, India
  • C.S. Mishra, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Project-X is the proposed high intensity proton facility to be built at Fermilab, US. Its Superconducting Linac, to be used at first stage of acceleration, will be operated in continuous wave (CW) mode. The Linac is divided into three sections on the basis of operating frequencies & six sections on the basis of family of RF cavities to be used for the acceleration of beam from 2.5 MeV to 3 GeV. The transition from one section to another can limit the acceptance of the Linac if these are not matched properly. We performed a study to calculate the acceptance of the Linac in both longitudinal and transverse plane. Investigation of most sensitive area which limits longitudinal acceptance and study of influence of failure of beam line elements at critical position, on acceptance are also performed.  
 
WEP221 CW Room-Temperature Bunching Cavity for the Project X MEBT 1900
 
  • G.V. Romanov, S. Barbanotti, E. Borissov, J.A. Coghill, I.G. Gonin, S. Kazakov, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  The Project-X, a multi-MW proton source based on superconducting linac, is under development at Fermilab. The front end of the linac contains a CW room temperature MEBT section which comprises ion source, RFQ and high-bandwidth bunch selective chopper. The length of the chopper exceeds 10 m, so four re-bunching cavities are used to support the beam longitudinal dynamics. The RF and mechanical designs of the re-bunching cavity including stress and thermal analysis are reported.  
 
TUP086 Microphonics control for Project X 988
 
  • W. Schappert, S. Barbanotti, J. Branlard, G.I. Cancelo, R.H. Carcagno, M.S. Champion, B. Chase, I.G. Gonin, A.L. Klebaner, D.F. Orris, T.J. Peterson, Y.M. Pischalnikov, L. Ristori, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Funding: Work is supported by the U.S. Department of Energy
The proposed multi-MW Project X facility at Fermilab will employ cavities with bandwidths as narrow as 20 Hz. This combination of high RF power with narrow bandwidths combined requires careful attention to detuning control if these cavities are to be operated successfully. Detuning control for Projects X will require a coordinated effort between the groups responsible for various machine subsystems. Considerable progress in this area has been made over the past year.
 
 
THOCS6 Progress in Cavity and Cryomodule Design for the Project X Linac 2133
 
  • M.S. Champion, S. Barbanotti, M.H. Foley, C.M. Ginsburg, I.G. Gonin, C.J. Grimm, J.S. Kerby, S. Nagaitsev, T.H. Nicol, T.J. Peterson, L. Ristori, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  The continuous wave 3 GeV Project X Linac requires the development of two families of cavities and cryomodules at 325 and 650 MHz. The baseline design calls for three types of superconducting single-spoke resonators at 325 MHz having betas of 0.11, 0.22, and 0.42 and two types of superconducting five-cell elliptical cavities having betas of 0.61 and 0.9. These cavities shall accelerate a 1 mA H beam initially and must support eventual operation at 4 mA. The electromagnetic and mechanical designs of the cavities are in progress and acquisition of prototypes is planned. The heat load to the cryogenic system is up to 25 W per cavity in the 650 MHz section, thus segmentation of the cryogenic system is a major issue in the cryomodule design. Designs for the two families of cryomodules are underway.  
slides icon Slides THOCS6 [2.241 MB]