Laser wakefield bubble regime acceleration of electrons in a preformed non uniform plasma channel

Abstract

A model of bubble regime electron acceleration by an intense laser pulse in non uniform plasma channel is developed. The plasma electrons at the front of the pulse and slightly off the laser axis in the plasma channel, experience axial and radial ponderomotive and space charge forces, creating an electron evacuated non uniform ion bubble. The expelled electrons travel along the surface of the bubble and reach the stagnation point, forming an electron sphere of radius re. The electrons of this sphere are pulled into the ion bubble and are accelerated to high energies. The Lorentz boosted frame enabled us to calculate energy gain of a test electron inside the bubble.

Breakdown of the ponderomotive approximation as an acceleration mechanism in wave-particle nonlinear dynamics

“…6,7 What remains as a needed crucial condition in all variants is the adjustment of a proper resonant phase between accelerating fields and particles. 2,8 Proper wave-particle tuning demands fine control of the beam-injection process, [9][10][11] so one might be interested in settings where tuning can be achieved automatically by the own system, without any extra intervention of the experimenter. One way to do that is to use intense electromagnetic waves in neutral gases-the gas is ionized and the resulting charged particles are self-adjustably accelerated by the waves.…”