Simulation study of positron production by picosecond laser-driven electrons

Positron production by picosecond laser-driven electrons has been studied via simulations. The laser parameters were chosen according to a typical 100 J/1 ps laser system, such as the XingGuang III laser. A near-critical density plasma was used to accelerate electrons. Then the positrons were generated by these electrons interacting with a high-Z converter. Particle-in-cell simulations of laser-plasma interaction indicate that the picosecond laser-accelerated electrons have a temperature up to 12 MeV with a beam charge of 800 nC (>5 MeV). The positron generation was simulated by a Monte Carlo toolkit. The simulation results show that with an optimal converter thickness the generated positron beam has a yield of 5 × 10 10 that is over one order of magnitude higher than that from direct laser-solid interaction. Graphical abstract