Abstract: A non-LTE average atom model which has been modified to include tunnel ionisation and ATI heating is presented, and the model is applied to study the optically ionised Li-like Ne recombination X-ray laser. Results from the calculation show that high gain in Li-like Ne at 9.8 nm can be produced with a 100 fsec duration, 0.248μm laser of intensity 2×10^-17Wcm^-2 and the gas density of 10^-3gcm^-3. The duration of X-ray lasing is about 1.5 psec.

Key words: Tunnel Ionisation, Above Threshold Ionisation, Game and Recombination X-ray lasers