High-density electron-ion bunch formation and multi-GeV positron production via radiative trapping in extreme-intensity laser-plasma interactions

Capdessus, R and Gremillet, L and McKenna, P (2020) High-density electron-ion bunch formation and multi-GeV positron production via radiative trapping in extreme-intensity laser-plasma interactions. New Journal of Physics, 22. 113003. ISSN 1367-2630 (https://doi.org/10.1088/1367-2630/abc1fa)

[thumbnail of Capdessus-etal-NJP-2020-High-density-electron-ion-bunch-formation-and-multi-GeV-positron-production]
Preview
 Text. Filename: Capdessus_etal_NJP_2020_High_density_electron_ion_bunch_formation_and_multi_GeV_positron_production.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo
Download (2MB)| Preview

Abstract

Multi-petawatt laser systems will open up a novel interaction regime mixing collective plasma and quantum electrodynamic processes, giving rise to prolific generation of gamma-ray photons and electron-positron pairs. Here, using particle- in-cell simulations, we investigate the physics of the interaction of a 1024W.cm−2 intensity, 30 fs duration, circularly polarized laser pulse with a long deuterium plasma at classically overcritical electron density (1022 cm−3). We show that radiative trapping of the plasma electrons causes a high-density (∼ 5×1023 cm−3), quasineutral electron-ion bunch to form inside the laser pulse. This phenomenon is accompanied by up to ∼ 40% energy conversion efficiency of the laser into gamma rays. Moreover, we find that both the radiation-modified Laplace force and the longitudinal electric field exerted on the positrons created by the multiphoton Breit-Wheeler process can accelerate them to GeV-range energies. We develop a theoretical model, the predictions of which provide a good match to the simulation results. Finally, we address the influence of the ion mass, showing that the laser absorption and positron acceleration is enhanced with deuterons compared to protons.

  • Item type:Article
    ID code:74340
    Dates:
    Date
    Event
    3 November 2020
    Published
    16 October 2020
    Accepted
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:22 Oct 2020 12:08
    Last modified:25 Apr 2024 01:19
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/74340
CORE (COnnecting REpositories)