Author: Ha, G.
Paper Title Page
WEPAB132 Research Program and Recent Results at the Argonne Wakefield Accelerator Facility (AWA) 2885
 
  • M.E. Conde, S.P. Antipov, D.S. Doran, W. Gai, Q. Gao, G. Ha, C.-J. Jing, W. Liu, N.R. Neveu, J.G. Power, J.Q. Qiu, J.H. Shao, Y.R. Wang, C. Whiteford, E.E. Wisniewski, L.M. Zheng
    ANL, Argonne, Illinois, USA
  • S.P. Antipov, C.-J. Jing, J.Q. Qiu
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • Q. Gao, L.M. Zheng
    TUB, Beijing, People's Republic of China
  • G. Ha
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • N.R. Neveu
    IIT, Chicago, Illinois, USA
  • Y.R. Wang
    IMP/CAS, Lanzhou, People's Republic of China
 
  Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357
We give an overview of the research program at the Argonne Wakefield Accelerator Facility (AWA), including some highlights of recent experiments. The AWA facility is dedicated to the study of beam physics and the development of technology for future particle accelerators. Two independent electron linacs are used to study wakefield acceleration: 70 MeV high charge electron bunches of up to 100 nC are used to drive wakefields, which can be probed by bunches originating from the same linac or from the 15 MeV linac. Recent Two-Beam-Acceleration (TBA) experiments operating at 11.7 GHz reached accelerating gradients of up to 150 MV/m. No indication of witness beam quality degradation was observed, and bunch charge was preserved during the acceleration process. Two identical TBA setups were used in series in order to demonstrate staging capabilities. Dielectric loaded structures operating at 26 GHz are also used in TBA experiments. Another main thrust of the research program consists of exploring and developing techniques to manipulate the phase space of electron bunches. These efforts include bunch shaping and the exchange of emittances in the transverse and the longitudinal phase spaces
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPAB132  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPVA022 RECENT TWO-BEAM ACCELERATION ACTIVITIES AT ARGONNE WAKEFIELD ACCELERATOR FACILITY 3305
 
  • J.H. Shao, S.P. Antipov, M.E. Conde, W. Gai, Q. Gao, G. Ha, W. Liu, N.R. Neveu, J.G. Power, Y.R. Wang, E.E. Wisniewski, L.M. Zheng
    ANL, Argonne, Illinois, USA
  • C.-J. Jing, J.Q. Qiu
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • J. Shi, D. Wang
    TUB, Beijing, People's Republic of China
 
  The Two-Beam Acceleration (TBA) is a modified approach to the structure-based wakefield acceleration which may meet the luminosity, efficiency, and cost requirement of a future linear collider. Recently, various TBA experiments have been carried out at the Argonne Wakefield Accelerator Facility (AWA). With X-band metallic power extractors and accelerators, a 70 MeV/m average accelerating gradient has been demonstrated in two stages while a 150 MeV/m gradient as well as 300 MW extracted power have been achieved in a single stage. In addition, low cost K-band dielectric power extractor and accelerator have also been developed. The preliminary results show power extraction of 55 MW and an average accelerating gradient of 28 MeV/m.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA022  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPIK017 Simultaneous Generation of Drive and Witness Beam for Collinear Wakefield Acceleration 535
 
  • G. Ha
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • M.E. Conde, D.S. Doran, W. Gai, J.G. Power
    ANL, Argonne, Illinois, USA
 
  Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357.
Generating the drive and witness bunch for collinear wakefield acceleration (CWFA) requires precise control of the longitudinal bunch shape for each bunch as well as the controlling their separation. The emittance exchange (EEX) beamline and a transverse mask can be used to achieve all of these requirements. First, this EEX-based method can independently control the longitudinal bunch shape of each bunches so that the drive bunch is shaped to generate a high transformer ratio while witness bunch is shaped to suppress its energy spread. Second, the timing jitter between the drive and witness bunch poses a serious limitation to the CWFA scheme but the EEX-based method eliminates this since both bunches are generated at the same time and share the exactly same beamline so there are no relative errors. In this paper, we confirm the feasibility of this EEX-based method for simultaneous generation with simulation for CWFA in a dielectric structure.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK017  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAB061 Limiting Effects in the Double EEX Beamline 3858
 
  • G. Ha
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • M.E. Conde, D.S. Doran, J.G. Power
    ANL, Argonne, Illinois, USA
 
  Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357.
The double emittance exchange (EEX) beamline is suggested to overcome the large horizontal emittance and transverse jitter issues associated with the single EEX beamline while preserving its powerful phase-space manipulation capability. However, the double EEX beamline also has potential limitations due to coherent synchrotron radiation (CSR) and transverse jitter. The former limitation arises because double EEX uses twice as many bending magnets as single EEX which means stronger CSR effects degrading the beam quality. The latter limitation arises because a longitudinal jitter in front of the first EEX beamline is converted into a transverse jitter in the middle section (between the EEX beamlines) which can cause beam loss or beam degradation. In this paper, we numerically explore the effects of these two limitations on the emittance and beam transport.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB061  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAB062 Preliminary Simulations on Chirpless Bunch Compression using Double-EEX Beamline 3862
 
  • G. Ha
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • M.E. Conde, D.S. Doran, W. Gai, J.G. Power
    ANL, Argonne, Illinois, USA
 
  Funding: This work is supported by Department of Energy, Office of High Energy Physics, under Contract No. DE-AC02-06CH11357.
An emittance exchange (EEX) beamline can be used to compress an electron bunch via its transverse-to-longitudinal exchange mechanism. We are investigating this as an alternative to the normal magnetic chicane bunch compressor. The chicane method requires a longitudinal chirp before the chicane (since it relies on the path length difference of different energies) which results in an unwanted chirp after the compressor. Alternatively, the EEX method uses quadrupole magnets to compress the bunch. In this paper, we present preliminary simulations in preparation for a demonstration of chirp-less bunch compression using an EEX beamline at the Argonne Wakefield Accelerator facility.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB062  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAB072 Application of Voronoi Diagram to Mask-Based Intercepting Phase-Space Measurements 3872
 
  • A. Halavanau, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • Q. Gao, J.G. Power, E.E. Wisniewski
    ANL, Argonne, Illinois, USA
  • Q. Gao
    TUB, Beijing, People's Republic of China
  • G. Ha
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • P. Piot
    Fermilab, Batavia, Illinois, USA
 
  Intercepting multi-aperture masks (e.g. pepper pot or multislit mask) combined with a downstream transverse-density diagnostics (e.g. based on optical transition radiation or employing scintillating media) are commonly used for characterizing the phase space of charged particle beams and the associated emittances. The required data analysis relies on precise calculation of the RMS sizes and positions of the beamlets originated from the mask which drifted up to the analyzing diagnostics. Voronoi diagram is an efficient method for splitting a plane into subsets according to the distances between given vortices. The application of the method to analyze data from pepper pot and multislit mask based measurement is validated via numerical simulation and applied to experimental data acquired at the Argonne Wakefield Accelerator facility. We also discuss the application of the Voronoi diagrams to quantify transversely-modulated beams distortion.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB072  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)