Magnetohydrodynamics (MHD) is the study of the interactive relationship between magnetic fields and electrically conducting gases or fluids, such as plasma. The General Atomics (GA) Theory Group has an extensive history of pioneering contributions to the study of MHD, including significant advances in analytic theory, large-scale numerical simulation, and quantitative study of actual experiments.
These studies have covered a broad range of topics, focusing particularly on the onset conditions and dynamics of important tokamak instabilities, including global pressure and current limiting instabilities, edge localized modes, resistive wall modes, and tearing modes.
A variety of theoretical frameworks have been developed and employed, from static ideal MHD to more comprehensive extended formulations incorporating rotation, resistivity, viscosity, fast ions, and other drift and kinetic effects. A major characteristic of GA MHD theory work is that the basic theory is informed by issues of numerical tractability to produce quantitative models. Both basic theory and numerical tool development are well grounded by continuous testing on applications.