Conversion efficiency of extreme ultraviolet radiation in laser-produced plasmas

A simple analytical model is presented for the conversion of laser beam energy into extreme ultraviolet radiation. The model is compared with experimental results to show good agreements under different conditions of the laser wavelength lambda(L), the laser intensity S-L, the pulse duration t(L), and the target atomic number Z(0). It turns out that relatively high conversion efficiencies are obtained when the Planck optical thickness of the plasma is tau approximate to 0.3-0.5, which is attained under an optimized combination of S-L and t(L) once lambda(L) is fixed. The lambda(L) scaling on the conversion efficiency is derived.