The General Atomics Tokamak Model (GATM) is a recently developed finite element (FE) environment for assessing the performance of tokamak magnet-plasma systems. Its generic environment is designed to assess magnet performance parameters for existing tokamaks, such as Doublet-III-D (DIII-D) and next-generation tokamak. GATM’s environment consists of a number of models, including a Comsol 3-D FE model and routines connecting this model to other GA tools. GATM consists of a 2-D axisymmetric module characterizing Poloidal Fields (PFs) system magnetic properties, including an equilibrium fitting code (EFIT) plasma representation. The 2-D module contains a central solenoid (CS) structural model for stress and deflection assessment. Toroidal field (TF) coils are characterized by a 3-D magnetics module for TF calculations and simulation of TF nonaxisymmetric ripple. PF and TF magnetics models provide input to a 3-D TF structural module, which simulates both in-plane and out-of-plane stress. A 3-D TF center post module uses input from the other three modules to evaluate the performance of a superconducting coil including details of the case, winding-pack, and superconducting cable. Model geometry, (Plasma, TF, CS, PF, and structures) is fully parametrized and allows for rapid assessment of arbitrary tokamak configurations. The GATM model is under development and is intended to interface with other general atomics models including: GA System Code (GASC), dynamic tokamak system model (TokSys), recently developed FUsion Synthesis Engine (FUSE), and DIII-D database, including EFIT. Models and current states generated in the GATM environment are output to engineering relevant codes ANSYS and SolidWorks. The article provides an overview of the present GATM environment and its application to DIII-D’s TF coil and an advanced tokamak (AT) Fusion Pilot Plant (FPP).

DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with fundamental plasma physics understanding and model validation, to drive scenario development by integrating high performance core and boundary plasmas. Substantial increases in off-axis current drive efficiency from an innovative top launch system for EC power, and in pressure broadening for Alfven eigenmode control from a co-/counter- I p steerable off-axis neutral beam, all improve the prospects for optimization of future long pulse/steady state high performance tokamak operation. Fundamental studies into the modes that drive the evolution of the pedestal pressure profile and electron vs ion heat flux validate predictive models of pedestal recovery after ELMs. Understanding the physics mechanisms of ELM control and density pumpout by 3D magnetic perturbation fields leads to confident predictions for ITER and future devices. Validated modeling of high- Z shattered pellet injection for disruption mitigation, runaway electron dissipation, and techniques for disruption prediction and avoidance including machine learning, give confidence in handling disruptivity for future devices. For the non-nuclear phase of ITER, two actuators are identified to lower the L–H threshold power in hydrogen plasmas. With this physics understanding and suite of capabilities, a high poloidal beta optimized-core scenario with an internal transport barrier that projects nearly to Q = 10 in ITER at ∼ 8 MA was coupled to a detached divertor, and a near super H-mode optimized-pedestal scenario with co- I p beam injection was coupled to a radiative divertor. The hybrid core scenario was achieved directly, without the need for anomalous current diffusion, using off-axis current drive actuators. Also, a controller to assess proximity to stability limits and regulate β N in the ITER baseline scenario, based on plasma response to probing 3D fields, was demonstrated. Finally, innovative tokamak operation using a negative triangularity shape showed many attractive features for future pilot plant operation.