Control of the laser accelerated electron beam

Monoenergetic electron beams have been generated in the self-injection scheme of laser acceleration. In applications of these laser accelerated electron beams, stable and controllable electron beams are necessary. A stable electron beam is generated in the self-injection scheme by using a Nitrogen gas jet target. We found the profile of the electron beam was manipulated by rotating the laser polarization. When we use a S-polarized laser pulse, a 20 MeV electron beam is observed with an oscillation in the image of the energy spectrum. From the oscillation, the pulse width of the electron beam is calculated to at most a few tens femtosecond. The direction of the electron beam is controlled by the gas jet position. (author)