Modeling of atomic processes of multiple charged ions in plasmas and its application to the study of EUV light sources

Atomic processes of multiple-charged ions of high-Z elements from tin to dysprosium are investigated for their application to light sources for extreme-ultra-violet (EUV) lithography. Modeling of these ions in plasmas, including tungsten, which is being considered for use as a divertor and wall material in the fusion devices, is discussed. Atomic spectra become very complex in the case of low-charged ions below Pd-like ions, which calls for a new atomic code for calculating the energy levels and rate coefficients of collisional and radiative processes. The collisional radiative model is validated through code comparison workshop activities. An alternative method for investigating the formation of the non-uniform structure of the plasmas is also presented.