Simulation of self-modulated laser wakefield acceleration using few TW in downramp injection and ionization injection regimes.

Simulations of transitional self-modulated laser wakefield acceleration driven by laser pulses of a few terawatts are discussed, comparing a downramp-based injection regime with an ionization injection regime. We demonstrate that a configuration using an gas target and a laser pulse of ∼75 with ∼2 peak power is a good alternative as a high repetition rate system that produces electrons of many tens of MeV, pC charge, and emittance of the order of 1 mm mrad.

Femtosecond laser-plasma dynamics study by a time-resolved Mach-Zehnder-like interferometer.

Side-view density profiles of a laser-induced plasma were measured by a home-built, time-resolved, Mach-Zehnder-like interferometer. Due to the pump-probe femtosecond resolution of the measurements, the plasma dynamics was observed, along with the pump pulse propagation. The effects of impact ionization and recombination were evidenced during the plasma evolution up to hundreds of picoseconds.