Plasma conditions generated by interaction of a high brightness, prepulse free Raman amplified KrF laser pulse with solid targets

A high brightness, Raman amplified KrF laser has been used to irradiate solid targets with 12 ps laser pulses at intensities above ${10}^{15}$ W/${\mathrm{cm}}^2$ without the presence of a preformed plasma caused by low level amplified spontaneous emission prepulse. Time-resolved x-ray spectroscopy of the K-shell emission from aluminum was used to infer electron densities in excess of ${10}^{23}$ ${\mathrm{cm}}^{\mathrm{-}3}$ at temperatures of several hundred electronvolts.