Intense electron and proton beams from PetaWatt laser-matter interactions

Recent experiments at the LLNL Petawatt Laser have demonstrated the generat ion of intense, high-energy beams of electrons and ions from the interactio n of ultra-intense laser light with solid targets. The focused laser intens ities are as high as 6 x 10(20) W/cm(2), at which point the quiver energies of the target electrons extend to similar to 10 MeV. In this new, fully re lativistic regime of laser-plasma interactions, nuclear processes become im portant and nuclear techniques are required to diagnose the high-energy par ticle production. We describe recent experiments in which we have observed electrons accelerated to 100 MeV, photo-nuclear fission, positron-electron pair creation, monoenergetic electron jets and intense beams of protons emi tted from the back surface of a laser-irradiated target. (C) 2000 Elsevier Science B.V. All rights reserved.