FIREWALL: A surrogate model for the rapid assessment of tokamak wall loading and melting by runaway electrons
Year: 2026
Type: preprint
Abstract: Runaway electron (RE) beams generated during tokamak disruptions can deposit highly localized heat loads on plasma-facing components, posing a serious risk of melting and damage. Monte Carlo particle transport simulations coupled with three-dimensional thermomechanical response modeling can quantify this damage but are too computationally demanding for device-scale assessments and extensive scenario scans. We present FIREWALL (Fast Integrated Runaway Electron WALL loads), a surrogate model that combines a database of \textsc{Geant4} volumetric energy-deposition profiles with a one-dimensional heat-diffusion solver for each wall element. FIREWALL retains the energy and incident angle distributions of impacting REs and predicts the spatiotemporal temperature evolution of detailed three-dimensional wall geometries up to the melting threshold. FIREWALL thus provides a fast physics-based framework for translating global RE simulations into global wall melting predictions, enabling large-scale screening of disruption scenarios while directing high-fidelity costly workflows to the limited wall regions where they are actually required.
Source: arXiv (Cornell University)
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: Implementation of activities described in the Roadmap to Fusion during Horizon Europe through a joint programme of the members of the EUROfusion consortium, G2293481551, G3562821882, G5404377299, Explosive events driven by runaway electron deposition in plasma-facing components, G8436673617, NAISS
OpenAlex ID: W7215128619