Author: Lebedev, V.A.
Paper Title Page
MOPPR072 Fermilab PXIE Beam Diagnostics Development and Testing at the HINS Beam Facility 954
  • V.E. Scarpine, B.M. Hanna, V.A. Lebedev, L.R. Prost, A.V. Shemyakin, J. Steimel, M. Wendt
    Fermilab, Batavia, USA
  Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
Fermilab is planning the construction of a prototype front end of the Project X linac. The Project X Injector Experiment (PXIE) is expected to accelerate 1 mA cw H beam up to 30 MeV. Some of the major goals of the project are to test a cw RFQ and H source, a broadband bunch-by-bunch beam chopper and a low-energy superconducting linac. The successful characterization and operation of such an accelerator places stringent requirements on beam line diagnostics. These crucial beam measurements include bunch currents, beam orbit, beam phase, bunch length, transverse profile and emittance, beam halo and tails, as well as the extinction performance of the broadband chopper. This paper presents PXIE beam measurement requirements and instrumentation development plans. Also presented are plans to test many of these instruments at the Fermilab High Intensity Neutrino Source (HINS) beam facility. Since HINS is already an operational accelerator, utilizing HINS for instrumentation testing allows for quicker development of the required PXIE diagnostics.
TUOBA03 H and Proton Beam Loss Comparison at SNS Superconducting Linac 1074
  • A.P. Shishlo, A.V. Aleksandrov, J. Galambos, M.A. Plum
    ORNL, Oak Ridge, Tennessee, USA
  • E. Laface
    ESS, Lund, Sweden
  • V.A. Lebedev
    Fermilab, Batavia, USA
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
A comparison of beam loss in the superconducting part (SCL) of the Spallation Neutron Source (SNS) linac for H and protons is presented. During the experiment the nominal beam of negative hydrogen ions in the SCL was replaced by a proton beam created by insertion of a thin stripping carbon foil placed in the low energy section of the linac. The observed significant reduction in the beam loss for protons is explained by a domination of the intra-beam stripping mechanism of the beam loss for H-. The details of the experiment are discussed, and a preliminary estimation of the cross section of the reaction H + H -> H + H0 + e is presented.
slides icon Slides TUOBA03 [0.772 MB]  
TUPPC040 Model Calibration and Optics Correction Using Orbit Response Matrix in the Fermilab Booster 1251
  • M.J. McAteer, S.E. Kopp
    The University of Texas at Austin, Austin, Texas, USA
  • V.A. Lebedev, E. Prebys
    Fermilab, Batavia, USA
  • A.V. Petrenko
    BINP SB RAS, Novosibirsk, Russia
  A beam-based method of optical model calibration using the measured orbit response matrix, known as the LOCO method, was successfully applied to Fermilab's rapid-cycling Booster synchrotron. Orbit responses were measured by individually changing the strength of each dipole corrector throughout the acceleration cycle, and dispersion was measured by changing the beam's radial offset. The model calibration procedure revealed large calibration errors for all elements in the Booster's recently-installed multipole corrector packages and beam position monitors. The resulting model was used to correct coupling and beta beating.  
WEPPD035 Design Considerations for an MEBT Chopper Absorber of 2.1MeV H at the Project X Injector Experiment at Fermilab 2585
  • C.M. Baffes, M.H. Awida, A.Z. Chen, Y.I. Eidelman, V.A. Lebedev, L.R. Prost, A.V. Shemyakin, N. Solyak, 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) will be a prototype of the Project X front end that will be used to validate the design concept and decrease technical risks. One of the most challenging components of PXIE is the wide-band chopping system of the Medium Energy Beam Transport (MEBT) section, which will form an arbitrary bunch pattern from the initially CW 162.5 MHz 5mA beam. The present scenario assumes diverting 80% of the beam to an absorber to provide a beam with the average current of 1mA to SRF linac. This absorber must withstand a high level of energy deposition and high ion fluence, while being positioned in proximity of the superconductive cavities. This paper discusses design considerations for the absorber, including specific challenges as spreading of energy deposition, management of temperatures and temperature-induced mechanical stresses, radiation effects, surface effects (sputtering and blistering), and maintaining vacuum quality. Thermal and mechanical analyses of a conceptual design are presented, and future plans for the fabrication and testing of a prototype are described.
WEPPD078 Progress with PXIE MEBT Chopper 2708
  • V.A. Lebedev, A.Z. Chen, R.J. Pasquinelli, D.W. Peterson, G.W. Saewert, A.V. Shemyakin, D. Sun, M. Wendt
    Fermilab, Batavia, USA
  • T. Tang
    SLAC, Menlo Park, California, USA
  Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
A capability to provide a large variety of bunch patterns is crucial for the concept of the Project X serving MW-range beam to several experiments simultaneously. This capability will be realized by the Medium Energy Beam Transport’s (MEBT) chopping system that will divert 80% of all bunches of the initially 5mA, 2.1 MeV CW 162.5 MHz beam to an absorber according to a pre-programmed bunch-by-bunch selection. Being considered one of the most challenging components, the chopping system will be tested at the Project X Injector Experiment (PXIE) facility that will be built at Fermilab as a prototype of the Project X front end. The bunch deflection will be made by two identical sets of travelling-wave kickers working in sync. Presently, two versions of the kickers are being investigated: a helical 200 Ω structure with a switching-type 500 V driver and a planar 50 Ω structure with a linear ±250 V amplifier. This paper will describe the chopping system scheme and functional specifications for the kickers, present results of electromagnetic measurements of the models, discuss possible driver schemes, and show a conceptual mechanical design.
WEPPD079 Measurements of Magnetic Permeability of Soft Steel at High Frequencies 2711
  • Y. Tokpanov, V.A. Lebedev, W. Pellico
    Fermilab, Batavia, USA
  The Fermilab Booster does not have a vacuum chamber which would screen the beam from laminations its dipoles cores. Therefore the booster impedance is mainly driven by the impedance of these dipoles. Recently an analytical model of the laminated dipole impedances was developed. However to match the impedance measurements with calculations one needs an accurate measurement of soft steel magnetic permeability. This paper presents the measurement results of the permeability in a frequency range from ~10 MHz to 1 GHz. Measurements of e.-m. wave propagation in 30 cm long strip line built from soft steel were used to compute the permeability. Measurements were performed in a DC magnetic field to observe the effect of steel saturation on the high frequency permeability. Both real and imaginary parts of the permeability were measured. As expected their values were decreasing with frequency increase from 10 MHz to 1 GHz and with saturation of steel DC permeability.
Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
WEPPR085 Observation of Instabilities of Coherent Transverse Ocillations in the Fermilab Booster 3129
  • Y. Alexahin, N. Eddy, E. Gianfelice-Wendt, V.A. Lebedev, W.L. Marsh, W. Pellico, A.K. Triplett
    Fermilab, Batavia, USA
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
The Fermilab Booster - built more than 40 years ago - operates well above the design proton beam intensity of 4.e12 ppp. Still, the Fermilab neutrino experiments call for even higher intensity of 5.5·1012 ppp. A multitude of intensity related effects must be overcome in order to meet this goal including suppression of coherent dipole instabilities of transverse oscillations which manifest themselves as a sudden drop in the beam current. In this report we present the results of observation of these instabilities at different tune, coupling and chromaticity settings and discuss possible cures.
THPPC030 Multi-physics Analysis of the Fermilab Booster RF Cavity 3347
  • M.H. Awida, M.S. Champion, T.N. Khabiboulline, V.A. Lebedev, J. Reid, V.P. Yakovlev
    Fermilab, Batavia, USA
  Funding: Operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE
After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.
THPPP054 A New Half-Wave Resonator Cryomodule Design for Project-X 3865
  • Z.A. Conway, A.O. Bergado, R.L. Fischer, M. Kedzie, M.P. Kelly, B. Mustapha, P.N. Ostroumov
    ANL, Argonne, USA
  • V.A. Lebedev
    Fermilab, Batavia, USA
  Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics and Nuclear Physics, under Contract DE-AC02-76CH03000 and DE-AC02-06CH11357.
We present the current status of our Project-X half-wave resonator cryomodule development effort. The Project-X injector requires a single cryomodule with 9 superconducting, 162.5-MHz, β = 0.11, half-wave resonators interleaved with 6 integrated superconducting solenoids/steering coils. This cryomodule is being designed and build by ANL with the intent of delivering a device which has all external connections to the cryogenic, RF, and instrumentation systems located at removable junctions separated from the clean cavity vacuum system. Issues include the ease of assembly, cavity cleanliness, interfacing to subsystems (e.g., cryogenics, couplers, tuners, etc.), and satisfying the ANL/FNAL/DOE guidelines for vacuum vessels. We employ proven warm-to-cold low-particulate beamline transitions to minimize unused space along the linac, a top-loading box design that minimizes the size of the clean room assembly, and compact beamline devices to minimize the length of the focusing period.
THPPP056 Beam Loss Due to Misalignments, RF Jitter and Mismatch in the Fermilab Project-X 3GeV CW Linac 3868
  • J.-P. Carneiro, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, A. Saini, B.G. Shteynas, N. Solyak
    Fermilab, Batavia, USA
  This paper presents an analysis of beam losses along the current design of the FNAL 3 GeV superconducting cw linac. Simulations from the RFQ exit up to the end of the linac (~430 meters) are performed on the FermiGrid using the beam dynamics code TRACK. The impact of beam mismatch, element misalignments, and RF jitter on the beam dynamics is discussed and corresponding beam loss patterns are presented. A correction scheme to compensate for misalignments is described.  
THPPP057 PXIE Optics and Layout 3871
  • V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, A.V. Shemyakin, B.G. Shteynas, N. Solyak
    Fermilab, Batavia, USA
  The Project X Injector Experiment (PXIE) will serve as a prototype for the Project X front end. The aim is to validate the Project-X design and to decrease technical risks, known to be mainly related to the front end. PXIE will accelerate a 1 mA CW beam to about 25 MeV. It will consist of an ion source, LEBT, CW RFQ, MEBT, two SC cryomodules, a diagnostic section and a beam dump. A bunch-by-bunch chopper located in the MEBT section will allow formation of an arbitrary bunch structure. PXIE deviates somewhat from the current Project-X front end concept in that it provides additional instrumentation and relies on a reduced number of kickers for bunch chopping; the diagnostic section also include an RF separator to allow studying extinction of removed bunches. The paper discusses the main requirements and constraints motivating the facility layout and optics. Final adjustments to the Project X front end design, if needed, will be based on operational experience gained with PXIE.
Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
THPPP058 PXIE: Project X Injector Experiment 3874
  • S. Nagaitsev, S.D. Holmes, R.D. Kephart, J.S. Kerby, V.A. Lebedev, C.S. Mishra, A.V. Shemyakin, N. Solyak, R.P. Stanek
    Fermilab, Batavia, USA
  • D. Li
    LBNL, Berkeley, California, USA
  • P.N. Ostroumov
    ANL, Argonne, USA
  A multi-MW proton facility, Project X has been proposed and is currently under development at Fermilab. As part of this development program, we are constructing a prototype of the front end of the Project X linac at Fermilab. The construction and successful operations of this facility will validate the concept for the Project X front end, thereby minimizing the primary technical risk element within the Project. The Project X Injector Experiment (PXIE) can be constructed over the period FY12-16 and will include an H ion source, a CW 2.1-MeV RFQ and two SC cryomodules providing up to 30 MeV energy gain at an average beam current of 1 mA. Successful operations of the facility will demonstrate the viability of novel front end technologies that will find applications beyond Project X in the longer term.  
THPPP063 CW Room Temperature Re-buncher for the Project X Front End 3880
  • G.V. Romanov, M.H. Awida, M. Chen, I.V. Gonin, S. Kazakov, R.A. Kostin, V.A. Lebedev, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
  At Fermilab there is a plan to construct the Project X Injector Experiment (PXIE) facility - a prototype of the front end of the Project X, a multi-MW proton source based on a superconducting linac. The construction and successful operations of this facility will validate the concept for the Project X front end, thereby minimizing the primary technical risk element within the Project. The front end of the linac contains a cw room-temperature MEBT section which comprises an ion source, RFQ, and high-bandwidth bunch selective chopper. The length of the MEBT exceeds 9 m, so three re-bunching cavities are used to support the beam longitudinal dynamics. The paper reports RF design of the re-bunchers along with preliminary beam dynamic and thermal analysis of the cavities.  
THPPP090 Project X Functional Requirements Specification 3945
  • S.D. Holmes, S. Henderson, R.D. Kephart, J.S. Kerby, I. Kourbanis, V.A. Lebedev, C.S. Mishra, S. Nagaitsev, N. Solyak, R.S. Tschirhart
    Fermilab, Batavia, USA
  Funding: Work supported by the Fermi Research Alliance, under contract to the U.S. Department of Energy.
Project X is a multi-megawatt proton facility being developed to support a world-leading program in Intensity Frontier physics at Fermilab. The facility is designed to support programs in elementary particle and nuclear physics, with possible applications to nuclear energy research. A Functional Requirements Specification has been developed in order to establish performance criteria for the Project X complex in support of these multiple missions, and to assure that the facility is designed with sufficient upgrade capability to provide U.S. leadership for many decades to come. This paper will describe the Functional Requirements for the Project X facility, their recent evolution, and the rationale for these requirements.
THPPP091 Status of the Project-X CW Linac Design 3948
  • J.-F. Ostiguy, P. Berrutti, J.-P. Carneiro, V.A. Lebedev, S. Nagaitsev, A. Saini, B.G. Shteynas, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
  Superconducting CW linac was proposed for Project X to accelerate H beam from 2.1 MeV to 3 GeV with nominal peak and average currents of respectively 5 mA and 1 mA. Linac built of 5 different families of resonators: half-wave, spoke (2), and elliptical (2) working at 162.5 MHz 325 MHz and 650 MHz to cover all energy range. Cavities and focusing elements are assembled in cryomodules. In baseline design all cryomodules are separated by short warm sections. It makes machine more reliable and maintainable and provide space for beam diagnostics and collimation. A long (~10m) gap between cryomodules at1 GeV is also being considered to provide space for beam extraction for nuclear experimental program. In paper we present the latest lattice of the linac baseline design and results of beam studies for this lattice. We briefly compare performance of the baseline design with alternative one without half-wave resonator section.  
THPPR041 The Conceptual Design of the Shielding Layout and Beam Absorber at the PXIE 4065
  • Y.I. Eidelman, J.S. Kerby, V.A. Lebedev, J.R. Leibfritz, A.F. Leveling, S. Nagaitsev, R.P. Stanek
    Fermilab, Batavia, USA
  The Project X Injector Experiment (PXIE) is a prototype of the Project X front end. A 30 MeV 50 kW H beam will be used to validate the design concept of the Project X. This paper discusses a design of the accelerator enclosure radiation shielding and the beam dump. Detailed energy deposition and activation simulation were performed with the MARS15 code. The simulation results guided the design of the installation enclosure.