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Title: Acceleration of a trailing positron bunch in a plasma wakefield accelerator

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. Here 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. Finally, the results thus mark the first acceleration of a distinct positron bunch in plasma-basedmore » particle accelerators.« less
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  1. Ecole Polytechnique, Palaiseau (France). Lab. d'Optique Appliquee (LOA); Univ. Paris-Saclay (France)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  3. Univ. of California, Los Angeles, CA (United States)
  4. Univ. of Colorado, Boulder, CO (United States)
  5. Univ. of Oslo (Norway). Dept. of Physics
  6. Tsinghua Univ., Beijing (China). Dept. of Engineering Physics
Publication Date:
Grant/Contract Number:
AC02-76SF00515; SC0010064; PHY-1415386; SC0008491; SC0008316; ACI-1339893; PHY-0960344; 715807; 2013CBA01501
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 2045-2322
Nature Publishing Group
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE; National Science Foundation (NSF); European Research Council (ERC); National Basic Research Program of China
Country of Publication:
United States
43 PARTICLE ACCELERATORS; Nonlinear phenomena; Plasma-based accelerators
OSTI Identifier: