Petawatt laser system and experiments

We have developed a hybrid Ti:sapphire-Nd: glass laser system that produces more than 1.5 PW of peak power. The system has produced up to 680 J of ene rgy on target at 1054 nm in a compressed 440 +/- 20-fs pulse by use of 94-c m diffraction gratings. A focused irradiance of up to 6 x 10(20) W/cm(2) wa s achieved using an on-axis parabolic mirror and adaptive optic wavefront c ontrol. Experiments with the petawatt laser system focused the beam on soli d targets and produced a strongly relativistic interaction. Energy content, spectra, and angular pattern of the photon, electron, and ion radiations w ere diagnosed in a number of ways, including several nuclear activation tec hniques. Approximately 40-50% of the laser energy was converted to broadly beamed hot electrons, with an associated bremsstrahlung beam. High luminosi ty ion beams were observed normal to the rear surface of various targets wi th energies up to greater than or equal to 55 MeV, representing similar to7 % of the laser energy. These and other results are presented.