Analysis of plasma density profiles and thermal transport in laser-irradiated spherical targets

Abstract

Measurements are presented for plasma density profiles, critical surface trajectories, and mass-ablation rates, as obtained from experiments in which layered spherical targets were irradiated with 1.05-μm laser light at intensities between 1×1014 and 1×1015 W/cm2. The targets were designed to allow study of thermal transport in overdense plasmas. They were from 70 to 110 μm in diameter, with a variable thickness parylene ablator and an aluminum substrate. Simulated results are consistent with all three sets of data if transport of both thermal and suprathermal electrons is severely inhibited, with a flux limiter of 0.03≤f≤0.06 being appropriate.