Abstract:

Understanding the impact of tungsten on tokamak performance and its mitigation by low-Z impurities is key to the success of ITER operations. A novel self-consistent gyrokinetic model, integrated into the XGC code [1,2], has been developed to comprehensively analyze tungsten transport and radiation. In this model, the tungsten ions are represented by a few bundles, with their fractional abundance determined by the atomic balance between ionization and recombination processes derived from ADAS rates [3]. The electron cooling by tungsten radiation is also derived from ADAS rates. This new model enables the study of tungsten radiation, transport dynamics, and interactions with low-Z species. Two complementary tungsten studies will be presented. First, we study the impact of nitrogen on the collisional and turbulent peaking factors of tungsten in a WEST plasma.Analysis of tungsten radiation with synthetic diagnostics will be discussed. Second, we explore the intricate interplay between collisional and turbulent transport in an H-mode plasma scenario of ASDEX Upgrade.

[1] Dominski et al. J. Plasm. Phys. (2019)

[2] Dominski et al. Phys Plasmas (2024)

[3] https://www.adas.ac.uk