Electron Injection into Plasma Wake Fields by Colliding Laser Pulses

An injector and accelerator is analyzed that uses three collinear laser pulses in a plasma: an intense pump pulse, which generates a large wake field ({ge}20 GV/m), and two counterpropagating injection pulses. When the injection pulses collide, a slow phase velocity beat wave is generated that injects electrons into the fast wake field for acceleration. Particle tracking simulations in 1D with injection pulse intensities near 10{sup 17} W/cm{sup 2} indicate the production of relativistic electrons with bunch durations as short as 3 fs, energy spreads as small as 0.3{percent}, and densities as high as 10{sup 18} cm{sup {minus}3} . {copyright} {ital 1997} {ital The American Physical Society}