Numerical analysis of 10ʹs femtosecond relativistic electron beam generation using single 12 TW50 fs laser pulse

Particle-in-cell two-dimensional (PIC-2D) simulations have been performed to verify the trapping of plasma electrons in the wake of ultrashort, multi-terawatt laser pulse as it propagates through underdense uniform plasma. It is supposed that the wake wavebreaking is the reason for the beam generation. This mechanism may lead to a compact ultrashort-pulse relativistic electron accelerator/injector (we call it laser–plasma linac). For a laser pulse with a duration of 50 fs and a peak power of 12 TW propagating through plasma, the simulation results show the generation of electron beam from the self-trapped plasma electrons with maximum energy >25 MeV and pulse duration of about 12 fs at FWHM. The two-dimensional effect of the plasma wave and the phase space of accelerated electrons are discussed. The present numerical results are relevant to the laser–plasma acceleration experiments that use the 12 TW 50 fs laser system at the Nuclear Engineering Research Laboratory (NERL), University of Tokyo.