The resistive ballooning mode (RBM) is an instability occurring in magnetized plasmas, particularly in magnetic confinement devices such as tokamaks, when the pressure gradient is opposite to the effective gravity created by a magnetic field.
The linear growth rate
of the RBM instability is given as where
is the effective gravity produced by a non-homogeneous magnetic field, R0 is the major radius of the device, Lp is a characteristic length of the pressure gradient, and cs is the plasma sound speed.
The RBM instability is similar to the Rayleigh–Taylor instability (RT), with Earth gravity
replaced by the effective gravity
, except that for the RT instability,
acts on the mass density
of the fluid, whereas for the RBM instability,
This plasma physics–related article is a stub.