The abrupt loss of thermal confinement and plasma current in a tokamak, called a "disruption," can lead to enormous transient heat loads and electromechanical forces in the tokamak.  Disruptions can also lead to the formation of high-energy "runaway electron" beams that can melt plasma-facing components.  M3D-C1 implements models of runaway electrons, conducting structures, and high-Z impurities that are injected to mitigate the risks from disruptions, enabling comprehensive, self-consistent modeling of these events.

As stellarator plasmas are heated, they can develop instabilities that create magnetic islands or regions of magnetic chaos.  M3D-C1 is able to simulate the plasma evolution under these conditions, including calculating the pressure gradients in regions of chaotic magnetic fields self-consistently with specified heating sources.  This makes it a unique tool for exploring both stability and non-ideal (nonintegrable) stellarator equilibria, including configurations with island divertors or nonresonant divertors.

Edge-localized modes (ELMs) are periodic instabilities in the edge tokamaks that melt or erode the plasma-facing components of the tokamak.  M3D-C1 has been used to calculate ELM stability thresholds, including in spherical tokamak configurations where non-ideal (resistive) effects become important for determining stability.  M3D-C1 has also been used extensively to calculate the plasma response to resonant magnetic perturbations (RMPs), which can be used to suppress ELMs under some conditions.

Tokamak core plasmas can exhibit a range of MHD instabilities that can strongly the attainable core pressure, including sawteeth, infernal modes, and tearing modes.  M3D-C1 has been used extensively to model these processes, showing how helical core modes can eliminate sawteeth, how infernal modes can lead to fast core temperature collapses, and finding the saturated widths of islands caused by tearing modes.

In a fusion power plant, the hot ions created by fusion reactions must be confined until the bulk of their energy has been transferred to the fusion fuel plasma through collisions.  These hot ions can drive and interact with MHD modes that degrade the confinement of the hot ions.  M3D-C1 includes the capability to model these processes using a particle-in-cell (PIC) method for describing hot ions or other kinetic species.