Technology
Beam diagnostics
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THPO079 RF Test of Standing Wave Deflecting Cavity with Minimized Level of Aberrations 866
THOP10   use link to see paper's listing under its alternate paper code  
 
  • V.V. Paramonov
    RAS/INR, Moscow, Russia
  • K. Flöttmann
    DESY, Hamburg, Germany
 
  For diagnostic of longitudinal distribution of electrons in unique REGAE bunches is applied a specially developed deflecting structure with minimized level of aberrations in the field distribution and improved RF efficiency. Short deflecting cavity was constructed and installed now in REGAE beam line. The cavity is tested at operational level of RF power. The main distinctive features of the cavity are mentioned and obtained results are reported.  
slides icon Slides THPO079 [1.803 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO079  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO080 Design Validation of a Chopping and Deflecting System for the High Current Injector at IUAC 869
 
  • S. Kedia, R. Ahuja, R. Kumar, R. Mehta
    IUAC, New Delhi, India
 
  A chopping and deflecting system has been designed and developed to provide the chopped beam with various repetition rates at the IUAC experimental facilities. It consists of four pairs of deflecting plates with increasing gap from 15 mm to 21 mm to maximize the effective electric field, preserve the beam emittance and to maximize the transmission efficiency within the same voltage conditions. The design of CDS has been validated with various simulation codes like CST MWS, Solid Works, Python and TRACE 3D. The deflecting plates have been fabricated, and assembled with in the design accuracy of 100 microns. A vacuum chamber has been designed and fabricated to incorporate the deflector plate assembly. The CDS unit has been installed in the Low Energy Ion Beam Facility at the IUAC to validate the design value of ion beam deflection. A slit has been installed to cut the deflected charge particles. Since the pulse power electronics required for chopping is presently under design we have used DC voltage across the four pairs of deflecting plates and amount of deflection was measured accordingly. The design, development, and DC beam test will be discussed in the article.  
poster icon Poster THPO080 [2.037 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO080  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO082 Physical Design of a Rectangular RF Deflector for Ultrashort Bunch Length Measurement 872
SPWR028   use link to see paper's listing under its alternate paper code  
 
  • J. Bai, Q.S. Chen, K. Fan
    HUST, Wuhan, People’s Republic of China
 
  Cylindrical deflectors which are now widely used for bunch length measurement suffer from the degeneration of polarization, while rectangular deflectors can separate polarization mode easily. This paper is focused on the study of a one-cell rectangular deflector, which is considerably different from cylindrical structure or multi-cell structure. A one-cell structure is free of π mode restriction and can achieve higher deflection efficiency per unit length. The proposed scheme is expected to achieve time resolution better than 200fs with the driving power less than 1MW. Cavity optimization and beam dynamic simulation are introduced in this paper.  
poster icon Poster THPO082 [0.484 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO082  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO083 Transverse Deflecting Cavity for Longitudinal Beam Diagnostics at BERLinPro 875
 
  • G. Kourkafas, T. Kamps, A. Neumann
    HZB, Berlin, Germany
  • B. Keune
    RI Research Instruments GmbH, Bergisch Gladbach, Germany
 
  The Berlin Energy Recovery Linac Prototype (BERLinPro) at Helmholtz Zentrum Berlin (HZB) aims to deliver a continuous-wave electron beam of high average current (100 mA) and brilliance (normalized emittance below 1 mm mrad). The achievement of these ambitious goals necessitates a thorough determination of the bunch parameters after the first acceleration stages, namely the photoinjector and the succeeding booster module. For the measurement of primarily the bunch duration and subsequently the longitudinal phase space and transverse slice emittance, a single-cell 1.3-GHz TM110-like mode vertically deflecting cavity was manufactured by RI Research Instruments GmbH, following the respective design developed for the Cornell ERL injector. This article summarizes the design parameters, manufacturing procedure and testing of this pulsed RF resonator, together with the expected temporal measurement resolution for the nominal beam energies at the initial acceleration stages of BERLinPro.  
poster icon Poster THPO083 [1.396 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO083  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO084 BPM Time of Flight Measurements for Setting-up the RF Cavities of the CERN Linac4 879
 
  • M. Bozzolan
    CERN, Geneva, Switzerland
 
  The newly constructed H LINAC4 at CERN has recently completed its first extended reliability run. It is equipped with Beam Position Monitors (BPMs) based on shorted-stripline pick-up electrodes to measure both position and Time of Flight (ToF). The ToF, in turn used to calculate the kinetic energy of the beam, is determined through signal phase shift measurements between pairs of BPMs. ToF measurements are performed by scanning of the phase of the RF injected into the cavities to find the nominal RF settings for optimal beam acceleration. This paper focuses on the technical aspects of the ToF measurement as well as on the results obtained during beam commissioning and their comparison with beam dynamics simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO084  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO086 Beam Loss and Average Beam Current Measurements Using a CWCT 882
 
  • F. Stulle, H. Bayle, J.F. Bergoz, T. Delaviere, L. Dupuy
    BERGOZ Instrumentation, Saint Genis Pouilly, France
  • P. Forck, M. Witthaus
    GSI, Darmstadt, Germany
  • D. Vandeplassche
    SCK•CEN, Mol, Belgium
  • J.X. Wu
    IMP/CAS, Lanzhou, People’s Republic of China
 
  The CWCT is a novel instrument adapted to an accurate average current determination of bunched CW beams or macro pulses. By combining a high-droop current transformer with novel electronics for signal analysis, an output signal bandwidth of DC to about 500kHz and a current resolution down to the micro-ampere level are achieved. Beam current fluctuations are followed within microseconds, permitting fast detection of beam loss. These characteristics render the CWCT an ideal instrument for HPPAs, for example ADS linacs, and other proton or ion accelerators. We present the CWCT principle and the CWCT performance achieved in beam experiments at UNILAC, GSI.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO086  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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FR1A01 Results From the 6D Diagnostics Test Bench at SNS 966
 
  • B.L. Cathey
    ORNL RAD, Oak Ridge, Tennessee, USA
  • A.V. Aleksandrov, S.M. Cousineau, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
 
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This work has been partially supported by NSF Accelerator Science grant 1535312.
This paper presents the method and results for measuring the full six-dimensional phase space of a low energy, high intensity hadron beam. This was done by combining four-dimensional emittance measurement techniques along with dispersion measurement and a beam shape monitor to provide the energy and arrival time components. The measurements were performed on the new Beam Test Facility (BTF) at the Spallation Neutron Source (SNS), a 2.5 MeV functional duplicate of the SNS accelerator front end. The results include a correlation the had not previously been observed.
 
slides icon Slides FR1A01 [7.083 MB]  
poster icon Poster FR1A01 [1.742 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-FR1A01  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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FR1A02 Bunch Length Measurements using Transverse Deflecting Systems 972
 
  • M. Hüning
    DESY, Hamburg, Germany
 
  Shorter and shorter bunch lengths (some 10 fs) require sophisticated bunch length measurent devices. Free electron lasers - but not only - use transverse deflecting systems. Employing suitable diagnostic tools measurements are not limited to bunch lengths but can be extended to longitudinal profiles and phase-space distributions, and slice emittances. Not only do successfully operated systems aid the commissioning and operation of FELs but they allow control over more sophisticated phase-space manipulations. The design and construction of such systems, actually operated at different RF frequencies, includes cavity design and fabrication, powerful RF systems, low level RF control, beam lines, diagnostics, and data analysis.  
slides icon Slides FR1A02 [6.054 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-FR1A02  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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FR1A03 Frontiers of Beam Diagnostics in Plasma Accelerators 977
 
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma, Italy
  • D. Alesini, M.P. Anania, M. Bellaveglia, F.G. Bisesto, M. Castellano, E. Chiadroni, G. Costa, M. Ferrario, F. Filippi, A. Giribono, A. Marocchino, A. Mostacci, R. Pompili, V. Shpakov, C. Vaccarezza, F. Villa
    INFN/LNF, Frascati (Roma), Italy
 
  Advanced diagnostics tools are crucial in the development of plasma-based accelerators. Accurate measurements of the beam quality at the exit of the plasma channel are mandatory for the optimization of the plasma accelerator. 6D electron beam diagnostics will be reviewed with emphasis on emittance measurement, which is particularly complex due to the peculiarity of the emerging beams.  
slides icon Slides FR1A03 [3.494 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-FR1A03  
About • paper received ※ 06 September 2018      issue date ※ 18 January 2019  
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FR1A04
Beam Diagnostics for CW and Pulsed Proton Superconducting Linac  
 
  • J.X. Wu
    IMP/CAS, Lanzhou, People’s Republic of China
  • J.S. Cao
    IHEP, Beijing, People’s Republic of China
 
  This talk will review beam diagnostics for CW and pulsed proton superconducting linac. Emphasis should be on those beam diagnostics developed for 10-25 MeV CW proton linac built by IMP and IHEP. The talk should present technical design and measurement results with beams by those beam diagnostic probes, and technical challenges and lessons learned can be also presented.  
slides icon Slides FR1A04 [10.921 MB]  
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