Hannover 2016 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

P: Fachverband Plasmaphysik

P 8: Laser Plasmas I

P 8.2: Talk

Tuesday, March 1, 2016, 15:00–15:15, b302

Laser-pulse-shape control of seeded QED cascades — •Matteo Tamburini, Antonino Di Piazza, and Christoph H. Keitel — Max Planck Institute for Nuclear Physics

The emergence of electron-positron cascades via ultrastrong electromagnetic fields constitutes a prominent manifestation of the complex interplay between strong-field QED processes and multiparticle dynamics. Here the onset and development of electron-positron cascades are investigated in the head-on collision of two realistic tightly focused ultraintense optical laser pulses in a tenuous gas [1]. As a consequence of the large ponderomotive forces expelling all electrons of the gas from the focal volume, we demonstrate that the onset of QED cascades may be prevented even at intensities around 10²⁶ W/cm² by focusing the laser energy almost down to the diffraction limit. Alternatively, a well controlled development of a QED cascade may be facilitated at laser intensities below 10²⁴ W/cm² per beam by enlarged focal areas and a rapid rise of the pulse or at total powers near 20 PW by employing suitable high-Z gases.

[1] M. Tamburini, A. Di Piazza, and C. H. Keitel, arXiv:1511.03987