Theory of High-Energy-Photon K-Shell Recombination Continuum Radiation From $Z$ -Pinch Plasmas

This paper presents explicit analytical formulas relating the X-ray yields in various energy bins of the free-bound recombination continuum to the mass, temperature, dimensions, and confinement time of the plasma participating in the K-shell emission. Estimates based on these formulas support the idea that K-shell recombination continuum radiation of argon, titanium, and iron can be a viable alternative to the K-shell line radiation of higher atomic number ions for advancing the operation of Z -pinch plasma radiation sources into the warm X-ray photon energy range of 10-20 keV. The potential of the refurbished Z accelerator for generating multikilojoule radiation yields in this energy range via recombination continuum is assessed.