Scientific Reports (Jul 2017)

Laser-pulse-shape control of seeded QED cascades

  • Matteo Tamburini,
  • Antonino Di Piazza,
  • Christoph H. Keitel

DOI
https://doi.org/10.1038/s41598-017-05891-z
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 8

Abstract

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Abstract QED cascades are complex avalanche processes of hard photon emission and electron-positron pair creation driven by ultrastrong electromagnetic fields. They play a fundamental role in astrophysical environments such as a pulsars’ magnetosphere, rendering an earth-based implementation with intense lasers attractive. In the literature, QED cascades were also predicted to limit the attainable intensity in a set-up of colliding laser beams in a tenuous gas such as the residual gas of a vacuum chamber, therefore severely hindering experiments at extreme field intensities. Here, we demonstrate that the onset of QED cascades may be either prevented even at intensities around 1026 W/cm2 with tightly focused laser pulses and low-Z gases, or facilitated at intensities below 1024 W/cm2 with enlarged laser focal areas or high-Z gases. These findings pave the way for the control of novel experiments such as the generation of pure electron-positron-photon plasmas from laser energy, and for probing QED in the extreme-intensity regime where the quantum vacuum becomes unstable.