Laser driven electron acceleration in vacuum, gases, and plasmas

In this paper we discuss some of the important issues pertaining to laser acceleration in vacuum, neutral gases, and plasmas. The limitations of laser vacuum acceleration as they relate to electron slippage, laser diffraction, material damage, and electron aperture effects, are discussed. An inverse Cherenkov laser acceleration configuration is presented in which a laser beam is self-guided in a partially ionized gas. Optical self-guiding is the result of a balance between the nonlinear self-focusing properties of neutral gases and the diffraction effects of ionization. The stability of self-guided beams is analyzed and discussed. In addition, aspects of the laser wakefield accelerator are presented and laser-driven accelerator experiments are briefly discussed.