magnetohydrodynamic instability

Magnetohydrodynamics (MHD) describes the behavior of electrically conducting fluids, such as plasmas, when they interact with electric and magnetic fields. These fields can be externally applied or generated by the plasma itself.1

In MHD, instabilities can arise, leading to turbulence and significant energy losses. These instabilities occur when a plasma seeks a lower energy state, much like a ball rolling down a hill. This can result in enhanced diffusion, increased electrical resistivity, and substantial heat loss. For instance, in toroidal plasma configurations, exceeding a critical current can trigger violent instabilities. While completely stable systems are difficult to achieve, significant progress has been made in mitigating major instabilities in laboratory settings. Magnetohydrodynamic waves are also a major source of variations in Earth's magnetic field, originating in the outer magnetic field and causing oscillations at Earth's surface.23