Electron Acceleration by a Radially Polarized Laser Pulse in an Ion Channel

The presence of a preformed ion channel in a laser accelerator enhances the oscillatory velocity of electrons due to the confined motions that leads to increase the energy gain from acceleration. The unique properties of radially polarized laser beam are utilized which leads to improvement in trapping and acceleration of electron so that an electron can be accelerated further to a very high energy level. The enhancement in electron energy is due to fact that the radial field vanishes on axis, but only axial field survives which accelerates the electron longitudinally. The electrostatic field generated by an ion channel stops the electrons to escape from the interaction region due to the transverse oscillations and thus causes a resonance between the electrons and the electric field of laser pulse. Our results show that the combined role of radial polarization and the effect of an ion channel can enhance the electron energy gain significantly.