Evolution of a high-temperature femtosecond surface plasma, recorded with time resolution

The results are given of experiments involving the generation (and subsequent probing) of a high-temperature surface plasma produced by 300 fs pulses of 5×10¹⁵ W cm^-2 intensity. An optical image of the plasma was formed. This made it possible to achieve not only temporal but also spatial resolution, and to determine the dynamics of the transverse structure of the plasma from reflection of a probe pulse. The recorded plasma temperature was 140 eV and the expansion velocity was of the order of 10⁷ cm s^-1.