On the possibility to improve positron acceleration on the rear surface of the target irradiated by intensive short laser pulse

The PM2D code is used to simulate relativistic electron-positron plasma generated in the target irradiated by laser light of relativistic intensities. The paper discusses results of PM2D simulations performed with the aim to increase mean energy and brightness of positron jets that could be formed near the rear surface of the target. The calculations demonstrate the possibility to significantly improve positron jet acceleration by target reconfiguring

The simulations of charged particle acceleration from gas target at 20 TW SOKOL-P laser with intensity of 5⋅1019 W/cm2

2D PIC code simulations have been performed for the optimization of gas jet target parameters to achieve a maximal energy and efficiency of charged particle acceleration in planned experiments at the 20 TW picosecond SOKOL-P laser. These calculations specify an opportunity to obtain energy up to Ee ∼ 200 MeV and efficiency ηe ∼ 10% for accelerated electrons and Ep ∼ 30 − 50 MeV and ηp ∼ 5% for accelerated protons in these experiments at laser intensity I ∼ 5 ⋅ 1019 W/cm2. They show the necessity of providing a formation of hydrogen jets with diameter ∼ 1mm, a gas molecule concentration ∼ 2 ⋅ 1019 cm−3 and steep density gradients ∼ 200 μm at the edge of the gas jet target for achieving these parameters of laser accelerated particle beams