Speaker
Description
EMC3-EIRENE scrape-off layer (SOL) simulations, with a domain extended to the first wall, are completed for the two scenarios which constitute the main targets of the Start of Research Operations (SRO) campaign in the ITER 2024 re-baseline: $B_T=5.3$ T, $I_P=15$ MA hydrogen L-modes and $B_T=2.65$ T, $I_P=7.5$ MA deuterium H-modes. These simulations also form part of a coordinated activity with the ITER Scientist Fellow Network boundary plasma modelling activity to cross-validate the EMC3-EIRENE, SOLPS-ITER and SOLEDGE3X codes on the SRO mission objective scenarios. The 3D EMC3-EIRENE boundary plasma calculations, including heat and particle loading onto the shaped wall geometry of the inertially cooled tungsten (W) Temporary First Wall (TFW) [1], will support studies of W sourcing, and erosion-migration of boron (B) layers deposited during boronization wall conditioning. An initial comparison of the predicted plasma, divertor, and wall loading profiles between EMC3-EIRENE and SOLPS-ITER are in reasonable agreement.
Additionally, EMC3-EIRENE modeling of non-axisymmetric SOL plasmas caused by the application of Resonant Magnetic Perturbations (RMP) for Edge Localized Mode (ELM) suppression is performed for the $B_T=2.65$ T deuterium H-mode SRO scenario. The perturbed magnetic field geometry is calculated by the MARS-F plasma response code for a scan of plasma current from $I_P=6.5→8$ MA ($q_{95}=3.4→2.7$). RMP coil phasing is optimized to maximize the displacement of the X-point $\xi_X$, a metric correlated with ELM suppression. For fixed $30$ kAt RMP current the magnetic footprint width on the outer divertor target varies between $17$ and $38$ cm when RMP current is scaled to maintain constant $\xi_X$=2 mm, the footprint width varies between $1.5$ and $25$ cm. Initial modeling results show that TFW particle load and temperature are modified by these RMP scenarios, particularly near the secondary null at the top of the vessel, and are expected to have a non-negligible impact on W sources and B layer lifetimes.
[1] R. A. Pitts et al., “Physics basis and status of the ITER tungsten First Wall”, Int. Conf. on Plasma Surface Interaction, 2026.