QED-PIC simulations of electromagnetic cascades at the surface of pulsar's polar cap.

The recent implementation of the QED module in the OSIRIS 3.0 framework has enabled to simulate various scenarios where pair production or gamma-rays emission can be produced with ultra-intense lasers and/or relativistic particles beams [1,2]. In this study we leverage on these numerical tools to study extreme astrophysical scenarios where self-consistent produced electron-positron pair plasmas are of relevance such as in pulsar magnetospheres. The dynamics of pulsar's polar cap cascade, based on the Ruderman-Sutherland model, has been investigated for the first time numerically in one dimension by Timokhin [3]. Including quantum synchrotron radiation additionally to curvature photon radiation for the possible processes responsible for photon emission, we present the results of one and two dimensional QED-PIC simulations of the development of electromagnetic cascades at the surface of the polar cap and the subsequent plasma discharges that are accompanied by strong electrostatic waves. [1] M. Vranic et al., NJP, in press (2016) [2] T. Grismayer et al., Physics of Plasmas 23, 056706 (2016) [3] A. N. Timokhin, Mon. Not. R. Astron. Soc. 408, 20922114 (2010)