High irradiance studies of laser-produced plasmas

The experimental portion of the laser plasma research program at Soreq is devoted mainly to the study of laser light absorption, plasma energy transport and the development and application of X-ray diagnostics. Experiments were conducted with 1.06 μm laser light pulses produced by either a mode-locked or a Q-switched Nd:YAG oscillator. Both short (60 psec) and long (2.5 nsec) pulses were used in the range of irradiances from 1013 to 1016 W/cm2. Low and high atomic number targets were irradiated with π and σ polarized light at both normal and oblique incidence. Results are given for 1) laser reflection and absorption, 2) momentum measurements, 3) electron-ion decay instabilities and 4) X-ray spectra of high atomic number targets. The computational program makes use of a one-dimensional Lagrangian laser-plasma simulation code which includes ionization and a perfect degenerate equation of state. The code is being used to calculate shock waves, pressure and compression in single and double layer targets. (author)