Laser electron acceleration in vacuum

This scheme involves pairs of intersecting linearly-polarized Gaussian-profile laser beams that are focused at crossover in vacuum and phased such that transverse field components cancel. The Ez components accelerate properly-phased z-axis relativistic electrons throughout a half-wave slip distance centered at crossover. The slip length is approximately 90λ for the case considered. The Ez components vanish rapidly before and after this slip region, thus providing conditions for a special case that is not included in Palmer's general acceleration theorem. Electron energy-gain gradients of several GeV/m appear to be possible.