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Litos MD, Ariniello R, Doss CE, Hunt-Stone K, Cary JR. Beam emittance preservation using Gaussian density ramps in a beam-driven plasma wakefield accelerator. Philos Trans A Math Phys Eng Sci 2019; 377:20180181. [PMID: 31230570 PMCID: PMC6602910 DOI: 10.1098/rsta.2018.0181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 04/24/2019] [Indexed: 06/09/2023]
Abstract
A current challenge that is facing the plasma wakefield accelerator (PWFA) community is transverse beam emittance preservation. This can be achieved by balancing the natural divergence of the beam against the strong focusing force provided by the PWFA plasma source in a scheme referred to as beam matching. One method to accomplish beam matching is through the gradual focusing of a beam with a plasma density ramp leading into the bulk plasma. Here, the beam dynamics in a Gaussian plasma density ramp are considered, and an empirical formula is identified that gives the ramp length and beam vacuum waist location needed to achieve near-perfect matching. The method uses only the beam vacuum waist beta function as an input. Numerical studies show that the Gaussian ramp focusing formula is robust for beta function demagnification factors spanning more than an order of magnitude with experimentally favourable tolerances for future PWFA research facilities. This article is part of the Theo Murphy meeting issue 'Directions in particle beam-driven plasma wakefield acceleration'.
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Affiliation(s)
- M. D. Litos
- Center for Integrated Plasma Studies, Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - R. Ariniello
- Center for Integrated Plasma Studies, Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - C. E. Doss
- Center for Integrated Plasma Studies, Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - K. Hunt-Stone
- Center for Integrated Plasma Studies, Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | - J. R. Cary
- Center for Integrated Plasma Studies, Department of Physics, University of Colorado Boulder, Boulder, CO, USA
- Tech-X, Boulder, CO, USA
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Doche A, Beekman C, Corde S, Allen JM, Clarke CI, Frederico J, Gessner SJ, Green SZ, Hogan MJ, O'Shea B, Yakimenko V, An W, Clayton CE, Joshi C, Marsh KA, Mori WB, Vafaei-Najafabadi N, Litos MD, Adli E, Lindstrøm CA, Lu W. Acceleration of a trailing positron bunch in a plasma wakefield accelerator. Sci Rep 2017; 7:14180. [PMID: 29079817 PMCID: PMC5660186 DOI: 10.1038/s41598-017-14524-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/11/2017] [Indexed: 11/21/2022] Open
Abstract
High gradients of energy gain and high energy efficiency are necessary parameters for compact, cost-efficient and high-energy particle colliders. Plasma Wakefield Accelerators (PWFA) offer both, making them attractive candidates for next-generation colliders. In these devices, a charge-density plasma wave is excited by an ultra-relativistic bunch of charged particles (the drive bunch). The energy in the wave can be extracted by a second bunch (the trailing bunch), as this bunch propagates in the wake of the drive bunch. While a trailing electron bunch was accelerated in a plasma with more than a gigaelectronvolt of energy gain, accelerating a trailing positron bunch in a plasma is much more challenging as the plasma response can be asymmetric for positrons and electrons. We report the demonstration of the energy gain by a distinct trailing positron bunch in a plasma wakefield accelerator, spanning nonlinear to quasi-linear regimes, and unveil the beam loading process underlying the accelerator energy efficiency. A positron bunch is used to drive the plasma wake in the experiment, though the quasi-linear wake structure could as easily be formed by an electron bunch or a laser driver. The results thus mark the first acceleration of a distinct positron bunch in plasma-based particle accelerators.
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Affiliation(s)
- A Doche
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Universite Paris-Saclay, 91762, Palaiseau, France.
| | - C Beekman
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Universite Paris-Saclay, 91762, Palaiseau, France
| | - S Corde
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Universite Paris-Saclay, 91762, Palaiseau, France.
| | - J M Allen
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - C I Clarke
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - J Frederico
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - S J Gessner
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - S Z Green
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - M J Hogan
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - B O'Shea
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - V Yakimenko
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - W An
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - C E Clayton
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - C Joshi
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - K A Marsh
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - W B Mori
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | | | - M D Litos
- University of Colorado Boulder, Boulder, CO, 80309, USA
| | - E Adli
- Department of Physics, University of Oslo, 0316, Oslo, Norway
| | - C A Lindstrøm
- Department of Physics, University of Oslo, 0316, Oslo, Norway
| | - W Lu
- Department of Engineering Physics, Tsinghua University, Beijing, 10084, China
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