Generation of dense and well-collimated positron beam via ultra-intense laser colliding with a flying plasma layer

With the forthcoming 10-100PW laser facilities, laser-driven electron-positron-pair production has gained particular interest. Here, a scheme to enhance the generation of dense electron-positron-pairs is proposed and numerically demonstrated, employing double laser pulses at the intensity level of 10(23)W cm(-2). The first laser accelerates a thin foil to a relativistic speed via the radiation-pressure-acceleration mechanism and a counter-propagating laser irradiates this flying plasma layer. The simulation results indicate that a high-yield and well-collimated positron beam (similar to 5.5x10(10) positrons/pulse, 8.8 nC/pulse) is generated with a large peak density (1.1x10(21) cm(-3)) by using tens-of-PW laser pulses.