Case Study: MIT Plasma Science and Fusion Center achieves ADX vacuum vessel resilience to reactor‑level plasma disruptions with COMSOL Multiphysics

Evaluating Structural Integrity in High Performance Nuclear Fusion Machines for Power Generation

The MIT Plasma Science and Fusion Center needed to evaluate and optimize the Advanced Divertor eXperiment (ADX) tokamak design to withstand reactor-level heat fluxes, magnetic fields and severe plasma disruptions. Using Comsol's COMSOL Multiphysics software, researchers simulated magnetic fields, eddy currents and Lorentz forces from worst-case vertical displacement events (1.5 million ampere plasma current, 6.5 T toroidal field) to assess stresses and deflections in the Inconel 625 modular vacuum vessel.

Comsol simulations coupled the electromagnetic and structural models to show that, without reinforcement, Lorentz loads could push stresses toward the Inconel 625 yield (460 MPa) and cause roughly 1 cm deflection—exceeding the ADX design limit of 306 MPa. By evaluating a design change that added a support block (an extra fixed boundary), the Comsol-enabled analysis demonstrated significantly reduced stress and displacement, bringing the vessel within the 306 MPa target and indicating the stabilized ADX vacuum vessel can survive disruptions and support operation.

MIT Plasma Science and Fusion Center

Jeffrey Doody

Mechanical Engineer