Soft X-ray population inversion in laser plasmas by resonant photoexcitation and photon-assisted processes

In this paper, the results of studies on soft X-ray population inversion by the resonant photoexcitation process are presented. The experimental studies in highly ionized multicomponent plasmas produced by high power glass laser indicate large population inversion densities at wavelengths Å. Intensity inversions of resonance lines from the and levels of Mg¹¹⁺ions at electron densities as high as 10²⁰cm^-3have been observed, indicating that gains of cm^-1have been achieved. These results and other photon-assisted soft X-ray population inversion schemes in inhomogeneous plasmas are discussed.