High intensity picosecond pulse interaction experiments

The development of intense short pulse (approx-lt lps) laser radiation focusable to extremely high intensities makes possible the investigation of many new regimes in atomic, plasma and nuclear physics. This paper reports on a high power Nd:glass laser system based on chirped pulse amplification which is being assembled for a variety of interaction experiments at focused intensities of up to 1018 W/cm2. Plans are underway to generate even higher intensities with a second laser system having an output energy in the 100 J range, which will also be used to study short-wavelength x-ray laser schemes. Initial interaction experiments at intensities of approx-lt 1016 W/cm2 have concentrated on characterizing energy coupling and x-ray generation with a range of plasma and x-ray diagnostics. These are made concurrent with the development of analytical and numerical models of the interaction mechanisms, atomic physics and hydrodynamics involved in these plasmas. Under prevailing focus spot irradiation conditions on planar solid targets of various materials, efficient coupling (<50%) to a short scale-length plasma is observed, with the creation of highly ionized states, as characterized by x-ray and XUV spectroscopy