Demonstration of aluminum

Targets consisting of 25$\un{nm}$ $\chem{Al}$ layers buried in solid carbon at depths of up to 400$\un{nm}$ have been irradiated with frequency doubled $\chem{Ti}$:sapphire laser pulses of 150$\un{fs}$ duration at an intensity of a few 1017 $\un{W/cm^2}$. The analysis of the emitted $\chem{Al}$ K-shell spectra yields densities close to that of solid $\chem{Al}$ and temperatures around 500$\un{eV}$. By using the cold $\chem{Si}$ $K_{\alpha}$ line for wavelength calibration, the presence of a red dense-plasma line shift for several K-shell resonance and associated satellite lines is clearly demonstrated