Subpicosecond time-resolved x-ray spectroscopy of plasmas produced by high-intensity ultrashort laser pulses

We present and discuss time resolved spectra (KeV range) of solid density plasmas produced by the interaction of clean high intensity laser pulses (400 fs, 0.53 micrometers light) with solid and foil targets at intensities between 1018 W/cm2 and 1020 W/cm2. Results have been obtained with the new PX1 x-ray stream camera which has a temporal resolution of 750 fs in the KeV x-ray range.