Modeling of overheated lithium plasma for EUV-source developing

The efficiency of extreme ultra-violet (EUV) source based on overheated lithium plasma was estimated. Plane layer with optical depth 0.01 cm was considered. Level kinetic equations were described and solved using elementary processes in plasma. Escape-factor method was applied for accounting of radiation field. Similar calculations were carried out using BELINE code with self-consistent accounting of level kinetics and radiation field. Calculations were carried out for temperatures $T=5\div 50$ eV and electron densities $N_e=10^{10}\div 10^{19}$ 1/cm$^3$.