A free-wave accelerator

In recent years, radically new methods for accelerating charged particles to high energies have been proposed. These methods have ranged from various kinds of plasma wave accelerators to inverse free electron lasers. Recently, the Free Wave Accelerator (FWA) was proposed whereby a large net energy is imparted to electrons via the field of an extremely powerful laser whose intensity produces quiver energies significantly greater than the electron rest mass. The authors present one- and three-dimensional calculations of the motion of relativistic electrons under the influence of an intense, linearly polarized laser and a static magnetic field, where strong acceleration of electrons is obtained. The electron dynamics in the case of a focused laser beam are compared to that of a pure plane wave. The focused laser beam tends to eject the electron due to the strong transverse ponderomotive force. It is shown that by depressing the laser beam`s central intensity the electron will remain within the focus