In the future International Thermonuclear Experimental Reactor (ITER), the interaction between the plasma and the tungsten chosen as the plasma-facing wall material imposes that the hot central plasma loses energy by X-ray emission from tungsten ions. On the other hand, the registered X-ray spectra provide alternative diagnostics of the plasma itself. Highly ionized tungsten emits extremely complex X-ray spectra that can be understood only after exhaustive theoretical studies. The detailed analyses will be useful for proper interpretation of soft X-ray plasma radiation expected to be registered on ITER-like machines, that is, Tungsten (W) Environment in Steady-state Tokamak (WEST). The simulations of the soft X-ray spectra structures for tungsten ions have been performed using the flexible atomic code (FAC) package within the framework of collisional-radiative (CR) model approach for electron temperatures and densities relevant to WEST tokamak.
This paper shows the theoretical predictions of the outer-shell ionization effect on the positions of Kα1,2, Kβ1,3, and K β2 X-ray lines for some 4d-transition metals (molybdenum and palladium) and 4f rare-earth elements (dysprosium and ytterbium). The ionization energy shifts have been evaluated using the multiconfiguration Dirac-Fock method, containing Breit interaction and quantum electrodynamic (QED) corrections. The presented results are important for obtaining the information about some parameters of plasma generated by different sources, especially by pulsed power machine and short-pulse lasers.