Imaging Electron Trajectories in a Laser-Wakefield Cavity Using Betatron X-Ray Radiation

Abstract : We demonstrate that betatron x-ray radiation accurately provides direct imaging of electrons trajectories accelerated in laser wakefields. Experimental far field x-ray beam profiles reveal that electrons can follow similar transverse trajectories with typical excursions of 1.5  μm±0.5  μm in the plane of laser polarization and 0.7  μm±0.2  μm in the plane perpendicular.