Kinetic Modeling of Seeded Nitrogen in an ITER Baseline Scenario

TL;DR

This paper models the behavior of seeded nitrogen impurities in an ITER baseline scenario using kinetic simulations, providing insights into impurity distribution and plasma performance impacts.

Contribution

It introduces a comprehensive kinetic modeling approach for nitrogen impurities in ITER, including detailed charge-state analysis and effects of refined ion transport.

Findings

Nitrogen charge-state distribution varies significantly in the plasma.

Refined ion transport modeling affects impurity density predictions.

Impurity behavior influences overall plasma confinement and performance.

Abstract

ITER as the next-level fusion device is intended to reliably produce more fusion power than required for sustainably heating its plasma. Modeling has been an essential part of the ITER design and for planning of future experimental campaigns. In a tokamak or stellarator plasma discharge, impurities play a significant role, especially in the edge region. Residual gases, eroded wall material, or even intentionally seeded gases all heavily influence the confinement and, thus, the overall fusion performance. Nitrogen is such a gas envisaged to be seeded into a discharge plasma. By modeling the impurities kinetically using the full three-dimensional Monte-Carlo code package EMC3-EIRENE, we analyze the distribution of nitrogen charge-state resolved in a seeded ITER baseline scenario and draw conclusions for the hydrogen background plasma density. Lastly, we compare the influence of a more refined kinetic ion transport in EIRENE including additional physical effects on the impurity density.