Scissor-cross ionization injection in laser wakefield accelerators

Abstract

We propose to use a frequency-doubled pulse colliding with the driving pulse at an acute angle to trigger ionization injection in a laser wakefield accelerator. This scheme effectively reduces the duration of the injection; thus, high injection quality is obtained. Three-dimensional particle-in-cell simulations show that electron beams with energy of , a charge of , energy spread of and normalized emittance of a few millimeter milliradian can be produced by laser pulses. By adjusting the angle between the two pulses, the intensity of the trigger pulse and the gas doping ratio, the charge and energy spread of the electron beam can be controlled.