Sheath instability

Sheath instability is an instability in a plasma where ions form sheaths near an electrode, making the plasma unstable. It is a type of Rayleigh–Taylor instability. It is given by the formula: $${\omega }^2-\left(\frac{e}{m}\right)E_0(L_n^{-1}+\frac{{n_1}^{\prime }}{n_0})-i\omega {v_0}^{\prime }=0$$