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

In simulations of a 12.5 PW laser (focussed intensity I = 4 x 10(23) Wcm(-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 10(26) m(-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 = 10(25) Wcm(-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. (C) 2013 AIP Publishing LLC