Properties of an exploding foil neon-like germanium soft X-ray laser

We describe the properties of the exploding foil neon-like germanium soft X-ray lasers having wavelengths of 19–28 nm and gain length product of more than 10. The measured X-ray intensity of lasing lines from an exploding foil target has been explained with the results of the plasma hydrodynamic code from the viewpoint of suitable condition of electron density and temperature for creating population inversion.