Drift waves

The characteristic frequency associated with drift waves involving electron flow^[3] is given by $${\displaystyle \omega ^{*}=k_{\perp }\left(-{\frac {k_{B}T_{e}}{eB_{0}}}\nabla n_{0}\right),}$$ where ${\displaystyle k_{\perp }}$ is the wavenumber perpendicular to the pressure gradient of the plasma, ${\displaystyle k_{B}}$ is the Boltzmann constant, ${\displaystyle T_{e}}$ is the electron temperature, ${\displaystyle e}$ is the elementary charge, ${\displaystyle B_{0}}$ is the background magnetic field and ${\displaystyle \nabla n_{0}}$ is the density gradient of the plasma.