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Roussel R, Andonian G, Lynn W, Sanwalka K, Robles R, Hansel C, Deng A, Lawler G, Rosenzweig JB, Ha G, Seok J, Power JG, Conde M, Wisniewski E, Doran DS, Whiteford CE. Single Shot Characterization of High Transformer Ratio Wakefields in Nonlinear Plasma Acceleration. Phys Rev Lett 2020; 124:044802. [PMID: 32058730 DOI: 10.1103/physrevlett.124.044802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/12/2019] [Indexed: 06/10/2023]
Abstract
Plasma wakefields can enable very high accelerating gradients for frontier high energy particle accelerators, in excess of 10 GeV/m. To overcome limits on single stage acceleration, specially shaped drive beams can be used in both linear and nonlinear plasma wakefield accelerators (PWFA), to increase the transformer ratio, implying that the drive beam deceleration is minimized relative to acceleration obtained in the wake. In this Letter, we report the results of a nonlinear PWFA, high transformer ratio experiment using high-charge, longitudinally asymmetric drive beams in a plasma cell. An emittance exchange process is used to generate variable drive current profiles, in conjunction with a long (multiple plasma wavelength) witness beam. The witness beam is energy modulated by the wakefield, yielding a response that contains detailed spectral information in a single-shot measurement. Using these methods, we generate a variety of beam profiles and characterize the wakefields, directly observing transformer ratios up to R=7.8. Furthermore, a spectrally based reconstruction technique, validated by 3D particle-in-cell simulations, is introduced to obtain the drive beam current profile from the decelerating wake data.
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Affiliation(s)
- R Roussel
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - G Andonian
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - W Lynn
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - K Sanwalka
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - R Robles
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - C Hansel
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - A Deng
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - G Lawler
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - J B Rosenzweig
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - G Ha
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Seok
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J G Power
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Conde
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - E Wisniewski
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D S Doran
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C E Whiteford
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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Gao Q, Ha G, Jing C, Antipov SP, Power JG, Conde M, Gai W, Chen H, Shi J, Wisniewski EE, Doran DS, Liu W, Whiteford CE, Zholents A, Piot P, Baturin SS. Observation of High Transformer Ratio of Shaped Bunch Generated by an Emittance-Exchange Beam Line. Phys Rev Lett 2018; 120:114801. [PMID: 29601751 DOI: 10.1103/physrevlett.120.114801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Indexed: 06/08/2023]
Abstract
Collinear wakefield acceleration has been long established as a method capable of generating ultrahigh acceleration gradients. Because of the success on this front, recently, more efforts have shifted towards developing methods to raise the transformer ratio (TR). This figure of merit is defined as the ratio of the peak acceleration field behind the drive bunch to the peak deceleration field inside the drive bunch. TR is always less than 2 for temporally symmetric drive bunch distributions and therefore recent efforts have focused on generating asymmetric distributions to overcome this limitation. In this Letter, we report on using the emittance-exchange method to generate a shaped drive bunch to experimentally demonstrate a TR≈5 in a dielectric wakefield accelerator.
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Affiliation(s)
- Q Gao
- Department of Engineering Physics, Tsinghua University Beijing, Beijing 100084, People's Repubic of China
- Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education, Beijing 100084, People's Repubic of China
| | - G Ha
- POSTECH, Pohang, Gyeongbuk 37673, Republic Of Korea
| | - C Jing
- Euclid Techlabs LLC, Bolingbrook, Illinois 60440, USA
| | - S P Antipov
- Euclid Techlabs LLC, Bolingbrook, Illinois 60440, USA
| | - J G Power
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - M Conde
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - W Gai
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - H Chen
- Department of Engineering Physics, Tsinghua University Beijing, Beijing 100084, People's Repubic of China
| | - J Shi
- Department of Engineering Physics, Tsinghua University Beijing, Beijing 100084, People's Repubic of China
| | - E E Wisniewski
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - D S Doran
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - W Liu
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - C E Whiteford
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - A Zholents
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - P Piot
- Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - S S Baturin
- The University of Chicago, PSD, Enrico Fermi Institute, 5640 S Ellis Avenue, Chicago, Illinois 60637, USA
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