Extreme Ultraviolet Radiation Transport in Laser-Irradiated High- Z Metal Foils

Spatially resolved extreme ultraviolet spectra were measured from the rear side of gold foils irradiated with 1.05-{μ}m wavelength, 100-ps pulses at intensities of 3×{} 10¹⁴ W/cm². In the energy range of 0.1 to 1.0 keV the radiation intensity decayed exponentially with foil thickness up to 1 {μ}m but remained almost constant over the range of 1 to 6 {μ}m. These results indicate that radiation heat conduction plays an important role in high-Z plasma energy transport. Ablation by the radiation heat flux is briefly discussed.