Dense electron-positron plasmas and bursts of gamma-rays from laser-generated quantum electrodynamic plasmas

Abstract

In simulations of a 12.5 PW laser (focussed intensity I=4×1023Wcm−2) striking a solid aluminum target, 10% of the laser energy is converted to gamma-rays. A dense electron-positron plasma is generated with a maximum density of 1026m−3, seven orders of magnitude denser than pure e− e+ plasmas generated with 1PW lasers. When the laser power is increased to 320 PW (I=1025Wcm−2), 40% of the laser energy is converted to gamma-ray photons and 10% to electron-positron pairs. In both cases, there is strong feedback between the QED emission processes and the plasma physics, the defining feature of the new “QED-plasma” regime reached in these interactions.