Dense electron-positron plasmas and gamma-ray bursts generation by counter-propagating quantum electrodynamics-strong laser interaction with solid targets

We use quantum electrodynamics (QED) particle-in-cell simulations to investigate and compare the generation of dense electron-positron plasmas and intense γ-ray bursts in the case of counter-propagating laser solid interaction (two-side irradiation) and single laser solid interaction (one-side irradiation). In the case of counter-propagating linearly polarized laser pulses irradiating a thin aluminum foil with each pulse peak power of 12.5 PW (I = 4 × 10²³W/cm²), we calculate that about 20% of the laser energy is converted into a burst of γ-rays with flux exceeding 10¹⁴s.⁻¹ This would be one of the most intense γ-ray sources among those currently available in laboratories. The γ-ray conversion efficiency in the case of two-side irradiation is three times higher than in the case of one-side irradiation using a single 12.5 PW laser. Dense electron-positron plasma with a maximum density of 6 × 10²⁷m⁻³ are generated simultaneously during the two-side irradiation which is eightfold denser compared to the one-side irradiation. The enhancement of the effects in the case of counter-propagating lasers are the results of the symmetrical compression of the foil target and the formation of electric potential and standing wave around the target. Realizing experimentally the proposed counter-propagating QED-strong laser-solid interaction to produce dense electron-positron pairs and prolific γ-rays will be made possible by the Extreme Light Infrastructure-Nuclear Physics facility under construction.