Ultrafast Synchrotron-Enhanced Thermalization of Laser-Driven Colliding Pair Plasmas

We report on the first self-consistent numerical study of the feasibility of laser-driven relativistic pair shocks of prime interest for high-energy astrophysics. Using a QED-particle-in-cell code, we simulate the collective interaction between two counterstreaming electron-positron jets driven from solid foils by short-pulse (similar to 60 fs), high-energy (similar to 100 kJ) lasers. We show that the dissipation caused by self-induced, ultrastrong (>10(6) T) electromagnetic fluctuations is amplified by intense synchrotron emission, which enhances the magnetic confinement and compression of the colliding jets.