Whole Device Modeling of ITER pedestal while including the physics of multiple gyrokinetic tungsten bundles

One of the main scientific objectives of the Exascale High-Fidelity Whole Device Modeling (WDM) project is the prediction of ITER pedestal height and shape. In view of the costly simulations, research has been conducted to model the whole device with core and edge regions coupled consistently [1]. On the other hand, ITER is a tungsten environment machine and tungsten ions are known to strongly affect the performance of the pedestal. An advanced stretch goal of the project concerns the inclusion of tungsten physics in the WDM simulation. This research has been initiated with the inclusion of impurities in XGC [2] and the implementation of tungsten bundles [3] to model the 74 ionization levels of tungsten ions with a few gyrokinetic bundles (~4 to 7), as it decreases the computational cost of such simulations. It was found that the particle fluxes depend strongly on the ionization state of tungsten and associated poloidal asymmetries [3]. The low-Z tungsten ions move inwardly from the scrape-off-layer to the core while high-Z tungsten ions move outwardly from the core to the pedestal. The overall dynamics leading to an accumulation of tungsten ion in the pedestal. We started to implement atomic interactions between tungsten bundles [4]. Preliminary results including atomic interactions between these tungsten bundles in a pedestal will be presented.

[1] J. Dominski, et al. Phys. of Plasmas 28, 022301 (2021)

[2] Dominski et al, Journal of Plasma Physics, 85 (5) 905850510 (2019)

[3] Dominski et al 27th IAEA Fusion Energy Conference (FEC 2018) 22–27 October 2018, Gandhinagar India (2018)

[4] Dominski et al 46th EPS Conference on Plasma Physics, 7-12 July 2019, Milan Italy (2019)