title: Mercier criterion
text: # Mercier criterion
  
  The Mercier criterion is a criterion for plasma used in the theoretical study of plasma instability. It was first proposed in 1954 by C. Mercier, who applied the perturbation method (in which $\omega ={\frac {\partial }{\partial t}}$ represents the frequency and $\mathbf {k} ={\frac {\partial }{\partial z}}$ is the z-direction of the unit vector) to the plasma mathematical model to compute calculations.
  
  