Scalings of laser-driven MeV electron sources with relativistic multi-picosecond laser pulses

We investigate the generation of MeV electrons in relativistic multi-picosecond laser-solid interactions, using 2D Particle-in-Cell simulations. Scanning a parameter space of intensities from 1E18 to 1E20 W/cm2 and pulse durations between 100 femtoseconds and 10 picoseconds, we discuss scalings of the effective hot electron temperature and MeV electron dose relevant to applications, as well the direct laser acceleration mechanism that drives electrons to energies much higher than the ponderomotive potential of the laser pulse.