Electron Acceleration by Longitudinal Electric Field of a Gaussian Laser Beam

Abstract

It is analytically shown that the longitudinal electric field of a Gaussian laser beam in vacuum accelerates an electron to an ultra-relativistic energy. The most favorable electron is accelerated in a length of twice the Rayleigh range. It is found that the ultimate energy increment of the electron with a single laser beam is given by the product of transverse field intensity and the beam waist. Also stability of the electron orbit and the trapping condition are discussed. The gain can be of the order of 100, MeV per single stage and then a multi-stage acceleration enables TeV-order-acceleration in a length of a few kilometers with the present state of the art.