Investigations of XUV and soft X-ray emission from plasmas produced by picosecond pulses from solid targets

Emission spectra in the range 10-250 AA from plasmas produced by picosecond laser pulses from a variety of solid targets are presented. These spectra provide some useful information about the state of ionization of the plasma and other plasma parameters such as temperature. Some of the results obtained are compared with the predictions of detailed numerical calculations. Ionization in these plasmas proceeds rapidly before reaching a limit. Depending on the laser energy input this limit generally occurs at a closed shell where further ionization is inhibited by the large jumps in the binding energy of the closed-shell electrons.