Spectroscopy of plasmas at solid density generated by ultra-short laser pulses

Abstract

Plasma close to solid density is generated by focusing a frequency doubled Ti-Sapphire laser delivering 150 fs high contrast pulses at an intensity of ≈1017 W/cm2 on solid flat targets. We will first discuss the mechanism of dense plasma production based on hydro code and PIC simulations and on measurements of the laser absorption and the energy transport into the dense target. Then we will present spectrally and temporally resolved measurements of aluminum K-shell spectra. Using a thin layer consisting of MgO or C on top of the Al we record Al K-shell spectra with strongly broadened and shifted lines. The analysis of the measured width and the red shift of the Ly-α line with its He-like satellites and of the He-β line with its Li-like satellites indicates the emission from a plasma at solid density with a temperature in the range 250 to 300 eV. The typical duration of the emission of these lines is ≈2 ps.