Low Dimensional Integrated Model for Simulating Magnetized Target Fusion Systems at General Fusion

Integrated numerical model being developed by General Fusion (GF) simulates magnetized target fusion (MTF) systems, in which liquid metal liner compresses spherical tokamak plasma to fusion conditions. The goal of this model is to guide the current design of Fusion Demonstration Plant (FDP) and the future design of an MTF reactor. The basic approach is to find the shape of the comression trajectory of the rotating liquid metal liner depending on the applied pressure pulses and the geometrical constraints. The code solves the reduced form of axisymmetric 2D Navier-Stokes equation, similar to the shallow water approximation where the fluid free surface is determined as function of poloidal coordinates and time. On the outer side, the code is coupled with self-consistent model of driving system, which produces the pressure pulses for liner compression. On the inner side, it is coupled to a target, which is a vacuum toroidal field diffusing into the liner, or a resistively evolving Grad-Shafranov plasma equilibrium. The main advantage of the code is its speed: the simple case takes several minutes of wall-clock time, allowing for fast optimization of FDP design. Comparison of simulations with ongoing GF compression experiments and results of FDP design optimization will be presented.