CHARACTERIZATION OF PLASMAS PRODUCED BY PICOSECOND AND NANOSECOND LASER-PULSES

The results of an extensive experimental investigation devoted to the characterization of laser produced plasmas will be considered in this paper. 600 ps laser pulses were employed to explode thin Al targets and generate long scalelength plasmas for interaction studies relevant to inertial confinement fusion. Thermal transport processes in underdense plasmas were investigated using time resolved X-ray imaging. Transport in micron-sized high density plasmas was also investigated in the picosecond regime, using X-ray spectroscopy. In this case the heat flux was found to be smaller than that predicted by the 1D modelling, with the flux inhibition increasing dramatically at high intensities (>10(16) W/cm(2)). Preliminary results will be presented which suggest that strong self-induced magnetic fields may arise during the interaction which may influence heat transport processes.