Production of hot near-solid-density plasma by electron energy transport in a laser-produced plasma

Targets with a layer of aluminum buried beneath a plastic overlay have been irradiated with 0.53 {μ}m wavelength, 20-ps pulse length light at (1--2)×{}10¹⁶ W cm^-2. The widths of Stark broadened Al xii 1s²¹{S}₀$--1s3p $¹P₁$ spectral lines and the ratios of satellite line intensities to the Al xii 1${s}²m¹S₀$--1s2p $¹P₁spectral line emitted from the aluminum layer imply electron densities up to (6--8)×{10}²²$ ${cm}^{{{-}}3}$. This result is a direct observation of significant energy transport to densities close to solid.