GeV electrons due to a transition from laser wakefield acceleration to plasma wakefield acceleration

摘要

We show through experiments that a transition from laser wakefieldacceleration (LWFA) regime to a plasma wakefield acceleration (PWFA) regime candrive electrons up to energies close to the GeV level. Initially, theacceleration mechanism is dominated by the bubble created by the laser in thenonlinear regime of LWFA, leading to an injection of a large number ofelectrons. After propagation beyond the depletion length, leading to adepletion of the laser pulse, whose transverse ponderomotive force is not ableto sustain the bubble anymore, the high energy dense bunch of electronspropagating inside bubble will drive its own wakefield by a PWFA regime. Thiswakefield will be able to trap and accelerate a population of electrons up tothe GeV level during this second stage. Three dimensional (3D) particle-in-cell(PIC) simulations support this analysis, and confirm the scenario.