# SMITER: A field-line tracing environment for ITER

## TL;DR

SMITER is a comprehensive GUI-based software environment for magnetic field-line tracing and power deposition mapping on ITER's plasma-facing components, integrating CAD, meshing, visualization, and parallel processing for accurate 3D modeling.

## Contribution

It introduces a new integrated framework combining CAD import, field-line tracing, and visualization tailored for ITER, with capabilities for finite element temperature computation and parallel processing.

## Key findings

- Benchmarking against existing codes shows high accuracy.
- Demonstrated power deposition mapping for various ITER plasma scenarios.
- Integrated visualization aids detailed analysis of plasma-facing components.

## Abstract

Built around the SMARDDA modules for magnetic field-line tracing [IEEE Tr. Plasma Sc. 42 (2014) 1932], the SMITER code package (SMARDDA for ITER) is a new graphical user interface (GUI) framework for power deposition mapping on tokamak plasma-facing components (PFC) in the full 3-D CAD geometry of the machine, taking as input a user-defined specification for parallel heat flux in the scrape-off layer (SOL) and a description of the equilibrium magnetic flux. The software package provides CAD model import and integration with the ITER Integrated Modelling and Analysis Suite (IMAS), parametric CAD components catalogue and modelling, CAD de-featuring for PFC surface extraction, meshing, visualization (using an integrated ParaView module), Python scripting and batch processing, storage in hierarchical data files, with several simulation cases in one study running in parallel and using message passing interface (MPI) for code speed-up. An integrated ParaView module can combine CAD geometry, magnetic field equilibrium, meshes and results for detailed setup analysis and a module is under development for full finite element computation of surface temperatures resulting from the power deposition patterns on 3-D PFCs. The code package has been developed for ITER, but can be deployed for similar modelling of any tokamak. This paper presents and discusses key features of this field-line tracing environment, demonstrates benchmarking against existing field-line tracing code and provides specific examples of power deposition mapping in ITER for different plasma configurations.