The process of high energy electron acceleration along the surface of grating targets which were irradiated by a relativistic, high contrast laser pulse at an intensity I=2.5x10<sup>20</sup> W/cm<sup>2</sup> was studied. Our experimental results demonstrate that for a grating target with a periodicity of twice the laser wavelength, the surface electron flux is more intense for a laser incidence angle which is larger compared to the resonance angle predicted by the linear model. An electron beam with a peak charge of ∼ 2.7 nC/sr, for electrons with energies >1.5\ MeV, was measured. Numerical simulations carried out with parameters similar to the experimental conditions also show an enhanced electron flux at higher incidence angles depending on the preplasma scale length. A theoretical model which includes ponderomotive effects with more realistic initial preplasma conditions suggests that the laser driver intensity and preformed plasma scale length are important for the acceleration process. The predictions closely match the experimental and computational results.
Zhu Xiaoming, Prasad Rajendra, Swantusch Marco, Aurand Bastian, Andreev Alexander , Willi Oswald, Cerchez Mirela. Relativistic Electron Acceleration by Surface Plasma Waves Excited with High Intensity Laser Pulses[J]. High Power Laser Science and Engineering, , (): .