Author: Power, J.G.
Paper Title Page
MOPOTK066 Damping-Ring-Free Injector Design for Linear Colliders 614
 
  • T. Xu, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • S.Y. Kim, P. Piot, J.G. Power
    ANL, Lemont, Illinois, USA
  • M. Kuriki
    HU/AdSM, Higashi-Hiroshima, Japan
 
  Funding: This work was supported by the US DOE contracts # DE-SC0018656 and # DE-SC0018234 (U.S.-Japan Science & Technology Cooperation Program in HEP) with NIU and No.DE-AC02-06CH11357 with ANL.
The current designs of future electron-positron linear colliders incorporate large and complex damping rings to produce asymmetric beams for beamstrahlung mitigation at the interaction point. This paper presents the design of an damping-ring-free electron injector capable of delivering flat electron beams with phase-space partition comparable to the electron-beam parameters produced downstream of the damping ring in the proposed international linear collider (ILC) design. The performance of the proposed configuration, its sensitivity to jitter along with its impact on spin-polarization is discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK066  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 13 June 2022
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MOPOTK067 High-Charge Transmission Diagnostics for Beam-Driven RF Structures 618
 
  • E.E. Wisniewski, G. Chen, D.S. Doran, S.Y. Kim, W. Liu, X. Lu, J.G. Power, C. Whiteford
    ANL, Lemont, Illinois, USA
  • X. Lu, D.C. Merenich
    Northern Illinois University, DeKalb, Illinois, USA
  • F. Stulle
    BERGOZ Instrumentation, Saint Genis Pouilly, France
  • E.E. Wisniewski
    Illinois Institute of Technology, Chicago, Illinois, USA
 
  Funding: U.S. Department of Energy Office of Science Contract No. DE-AC02-06CH11357.
The Argonne Wakefield Accelerator group (AWA) has been using high Charge bunch-trains (>450 nC) for structure wakefield RF power generation and high power testing (100 s of MW) for many years. These experiments involve fast beam-tuning for high charge transmission through small aperture wakefield structures over a large range of charge levels. The success of these experiments depends on real-time, non-destructive, fast charge measurements with devices that are robust in the high-charge and high-powered RF environment. AWA uses Bergoz Integrating Charge Transformers (ICT) which are ideal for these critical charge measurements. The devices used, the method developed and its application are detailed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK067  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022
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MOPOMS014 Commissioning of a High-Gradient X-Band RF Gun Powered by Short RF Pulses from a Wakefield Accelerator 652
SUSPMF040   use link to see paper's listing under its alternate paper code  
 
  • W.H. Tan, X. Lu, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • S.P. Antipov, C.-J. Jing, E.W. Knight, S.V. Kuzikov
    Euclid TechLabs, Solon, Ohio, USA
  • D.S. Doran, G. Ha, C.-J. Jing, W. Liu, X. Lu, P. Piot, P. Piot, J.G. Power, J. Shao, C. Whiteford, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
 
  Funding: This work is supported by the U.S. DOE, under award No. DE-SC0018656 to NIU, DOE SBIR grant No DE-SC0018709 at Euclid Techlabs LLC, and contract No. DE-AC02-06CH11357 with ANL.
A high-gradient X-band (11.7-GHz) photoinjector developed by Euclid Techlabs, was recently commissioned at the Argonne Wakefield Accelerator (AWA). The system comprises a 1+1/2-cell RF gun powered by short RF pulses generated as a train of high-charge bunches from the AWA accelerator passes through a slow-wave power extraction and transfer structure. The RF photoinjector was reliably operating with electric fields in excess of 300 MV/m on the photocathode surface free of breakdown and with an insignificant dark-current level. We report on the RF-gun setup, commissioning, and the associated beam generation via photoemission.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS014  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 19 June 2022
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WEOZSP1 Longitudinal Bunch Shaping Using an X-Band Transverse Deflecting Cavity Powered by Wakefield Power Extractor at Argonne Wakefield Accelerator Facility 1655
 
  • S.Y. Kim, G. Chen, D.S. Doran, W. Liu, J.G. Power, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • A. Bibian, C.-J. Jing, E.W. Knight, S.V. Kuzikov
    Euclid TechLabs, Solon, Ohio, USA
  • P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
 
  Funding: This project is supported under DoE SBIR Phase I Grant No. DE-SC0021733. This work is also supported by Department of Energy, Office of Science, under contract No. DEAC02-06CH11357.
Longitudinal bunch shaping using transverse deflecting cavities (TDC) was recently proposed*. This configuration is well suited for shaping the current profile of high-charge bunches since it does not use dipole magnets, and therefore, is not prone to deleterious effects arising from coherent synchrotron radiation. An intercepting mask located downstream of the first TDC, which introduce a spatiotemporal correlation, transversely shape the beam. Downstream of the second TDC, upon removal of the cross-plane correlation, the bunch is temporally shaped. In this paper, we investigate longitudinal bunch shaping with an X-band TDC powered by an X-band, short-pulse wakefield Power Extraction and Transfer Structure (PETS), where the wakefield from the drive beam propagating through the PETS is the power source. We describe the RF designs of the X-band TDC and the configuration of the overall shaping system. Finally, we explore via beam-dynamics simulations the performances of the proposed shaper and its possible application to various bunch shapes relevant to beam-driven acceleration and coherent radiation generation.
*Gwanghui Ha et al., Phys. Rev. Accel. Beams 23, 072803, 2020
 
slides icon Slides WEOZSP1 [6.235 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP1  
About • Received ※ 14 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 17 June 2022
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WEPOST046 Beam Matching in an Elliptical Plasma Blowout Driven by Highly Asymmetric Flat Beams 1802
SUSPMF037   use link to see paper's listing under its alternate paper code  
 
  • P. Manwani, H.S. Ancelin, G. Andonian, N. Majernik, J.B. Rosenzweig, M. Yadav
    UCLA, Los Angeles, California, USA
  • G. Andonian
    RadiaBeam, Marina del Rey, California, USA
  • G. Ha, J.G. Power
    ANL, Lemont, Illinois, USA
  • M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
  • M. Yadav
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This work was performed with the support of the US Department of Energy under Contract No. DE-SC0017648 and DESC0009914.
Particle beams with highly asymmetric emittance ratios, or flat beams, are employed at accelerator facilities such as the AWA and foreseen at FACET-II. Flat beams have been used to drive wakefields in dielectric structures and are an ideal candidate for high-gradient wakefields in plasmas. The high aspect ratio produces a blowout region that is elliptical in cross section and this asymmetry in the ion column structure creates asymmetric focusing in the two transverse planes. The ellipticity of the plasma blowout decreases as the normalized peak current increases, and gradually approaches an axisymmetric column. An appropriate matching condition for the beam envelope inside the elliptical blowout is introduced. Simulations are performed to investigate the ellipticity of the resultant wakefield based on the initial drive beam parameters, and are compared to analytical calculations. The parameter space for two cases at the AWA and FACET facilities, with requirements for plasma profile and achievable fields, is presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST046  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 29 June 2022
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WEPOPT065 Simulations of the Upgraded Drive-Beam Photoinjector at the Argonne Wakefield Accelerator 2015
 
  • E.A. Frame, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • S.Y. Kim, X. Lu, J.G. Power, D.S. Scott, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
 
  Funding: Department of Energy
The Argonne Wakefield Accelerator (AWA) is planning to upgrade its photoinjector for the drive-beam accelerator. The main goal of the upgrade is to improve the beam brightness using a symmetrized RF-gun cavity. In the process, the photoinjector was reconfigured and some of the solenoid magnets redesigned. A challenging aspect of this optimization is that the injector should be able to produce bright low-charge (~1 nC) bunches while also being capable of operating at high-charge (~50 nC) bunches. This paper will discuss the optimization of the beam dynamics for the low- and high-charge cases and explore the performances of the proposed configuration using a model of the full AWA drive-beam beamline including 3D field maps for the external electromagnetic fields. The optimizations are performed with ASTRA and the DEAP toolbox and with OPAL.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT065  
About • Received ※ 08 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022  
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FROXSP2 Demonstration of Gradient Above 300 MV/m in Short Pulse Regime Using an X-Band Single-Cell Structure 3134
 
  • J.H. Shao, D.S. Doran, G. Ha, C.-J. Jing, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • H.B. Chen, X. Lin, M.M. Peng, J. Shi, H. Zha
    TUB, Beijing, People’s Republic of China
  • C. Jing
    Euclid Beamlabs, Bolingbrook, USA
 
  High gradient acceleration is one of the critical technologies required by future linear colliders, free-electron lasers, and compact linac-based applications. Among decade long effort to break state-of-the-art gradient limitation of ~100 MV/m in normal conducting structures, using RF pulses shorter than 20 ns is a promising approach based on theoretic analysis and experimental observation. In this study, we demonstrated high gradient above 300 MV/m using an X-band 11.7 GHz single-cell travelling-wave structure with 6 ns FWHM RF pulses generated by a power extractor. In comparison, a scaled 11.424 GHz structure only reached below 150 MV/m driven by 30-100 ns RF pulses from a klystron with pulse compression. The experimental results and the suggested new mechanism of beam acceleration in the Breakdown Insensitive Acceleration Regime (BIAR) are presented in this manuscript.  
slides icon Slides FROXSP2 [8.998 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-FROXSP2  
About • Received ※ 11 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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