Flexible Optimized Coils Using Space curves (FOCUS)

FOCUS can be used to design the complex coils in stellarator fusion reactors. A key advantage of FOCUS is that it does not require a predefined winding surface, offering more flexibility in finding optimal coil shapes compared to older methods. Instead, FOCUS directly optimizes the 3D shapes of the coils to produce the desired magnetic field for plasma confinement. This allows FOCUS to design various types of coils, like modular and helical ones, while balancing speed and accuracy.

FOCUS Details

The HYM code is a nonlinear 3D simulation program designed to study the stability of field-reversed configurations (FRCs). FRCs are promising magnetic configurations for fusion energy research, visualized as self-contained plasmas where magnetic field lines form closed loops without a central conductor. The HYM code is important because it uses various physics models, such as resistive magnetohydrodynamics and hybrid models that treat ions as particles and electrons as a fluid, enabling detailed analysis of these FRCs. A vital aspect of HYM is its unique delta-f particle simulation method, which helps researchers better understand the physics of instabilities within the plasma of FRCs in kinetic regimes by minimizing numerical noise. The code's ability to switch to a standard particle-in-cell method allows for the investigation of early and later stages of instability in FRCs. 

M3D-C1

M3D-C1 is a computational code that solves the extended magnetohydrodynamic equations, a model that describes plasma as an electrically conducting fluid composed of ions and electrons. This code is primarily used to calculate the equilibrium, stability and dynamics of fusion plasmas but has also been applied to various other areas, including astrophysical research. M3D-C1 is specifically designed to address some of the most critical challenges in tokamak plasmas, including large-scale instabilities and disruptions.

M3D-C1 Details

STELLOPT

STELLOPT is a computational code used to optimize 3D magnetohydrodynamic equilibria for stellarator design and equilibrium reconstruction. It works by adjusting plasma-shaping and magnetic configurations to meet target parameters, improving stability and confinement. STELLOPT interfaces with the VMEC 3D equilibrium solver and can incorporate experimental data to reconstruct plasma states. It is also used to explore engineering constraints in fusion devices, such as coil design and divertor configurations.

STELLOPT Details

Stepped Pressure Equilibrium Code (SPEC)

SPEC is designed to solve 3D magnetohydrodynamic (MHD) equilibria with stepped-pressure profiles, meaning areas where plasma pressure changes abruptly. Unlike models that assume fully nested magnetic surfaces, where magnetic field lines form smooth, continuous layers around the plasma without intersecting, SPEC allows for solutions that include magnetic islands and chaotic regions, which influence plasma confinement and stability. It is a spectral-element code, meaning it divides the plasma into smaller regions to improve accuracy. SPEC finds the lowest energy plasma states by optimizing the multiregional, relaxed-MHD (MRxMHD) energy functional, a mathematical approach that balances magnetic and plasma forces in each region.

SPEC Details

X-Point Included Gyrokinetic Code (XGC)

XGC is a gyrokinetic particle-in-cell (PIC) code designed to simulate the edge region of magnetically confined fusion plasmas. Unlike fluid-based models, gyrokinetic simulations track individual particle motions to capture small-scale turbulence and kinetic effects. XGC can model both tokamak and stellarator geometries, providing insight into plasma behavior near critical boundary regions. Its simulation domain includes the magnetic separatrix, which divides confined plasma from escaping particles, the magnetic axis, the center of the plasma's magnetic field structure and the biased material wall, which interacts with escaping plasma. These capabilities make XGC important for studying plasma turbulence, transport and interactions with reactor walls.

XGC Details