Thermal transport measurements of UV laser irradiated spherical targets

New measurements are presented of thermal transport in spherical geometry using time-resolved X-ray spectroscopy. The time dependence of the mass ablation rate m(dot) was determined by following the progress of the ablation surface through thin layers of material embedded at various depths below the surface of the target. These measurements made with 6 and 12 UV (351 nm) beams from OMEGA are compared to previous thermal transport data and are in qualitative agreement with detailed LILAC hydrodynamic code simulations which predict a sharp decrease in m(dot) after the peak of the laser pulse. Non-uniform laser irradiation of the target results in the anomalously high values of m(dot) measured in these experiments.