Electron Acceleration in Wakefield and Supra-Bubble Regimes by Ultraintense Laser with Asymmetric Pulse

Electron acceleration in plasma driven by circular polarized ultraintense laser with asymmetric pulse areinvestigated analytically and numerically in terms of oscillation-center Hamiltonian formalism.Studies include wakefieldacceleration,which dominates in blow-out or bubble regime and snow-plow acceleration which dominates in supra-bubbleregime.By a comparison with each other it is found that snow-plow acceleration has lower acceleration capability.Inwakefield acceleration,there exists an obvious optimum pulse asymmetry or/and pulse lengths that leads to the highnet energy gain while in snow-plow acceleration it is insensitive to the pulse lengths.Power and linear scaling lawsfor wakefield and snow-plow acceleration respetively are observed from the net energy gain depending on laser fieldamplitude.Moreover,there exists also an upper and lower limit on plasma density for an effective acceleration in bothof regimes.