Drift waves explained

In plasma physics, a drift wave is a type of collective excitation that is driven by a pressure gradient within a magnetised plasma, which can be destabilised by differences between ion and electron motion (then known as drift-wave instability or drift instability). The drift wave typically propagates across the pressure gradient and is perpendicular to the magnetic field. It can occur in relatively simple configurations such as in a column of plasma with a non-uniform density but a straight magnetic field.^[1] Drift wave turbulence is responsible for the transport of particles, energy and momentum across magnetic field lines.^[2]

The characteristic frequency associated with drift waves involving electron flow^[3] is given by$$\backslash omega^*\; =\; k\_\backslash perp\; \backslash left(-\backslash frac\backslash nabla\; n\_0\backslash right),$$where

k _{\perp} is the wavenumber perpendicular to the pressure gradient of the plasma, k _{B} is the Boltzmann constant, T _{e} is the electron temperature, e is the elementary charge, B _{0} is the background magnetic field and \nabla n _{0} is the density gradient of the plasma.

Notes and References

1. Book: Goldston. Robert J.. Introduction to plasma physics. Rutherford. Paul H.. Institute of Physics. 1995 . 0-7503-0325-5 . Bristol, UK. 21. Drift waves and instabilities. 33079555.
2. Horton. W.. 1999. Drift waves and transport . Reviews of Modern Physics . en . 71 . 3. 735–778. 10.1103/RevModPhys.71.735 . 1999RvMP...71..735H . 0034-6861 . 2152/61083 . 122400874 . free.
3. Book: Chen, Francis F.. Introduction to plasma physics and controlled fusion . 2016 . 978-3-319-22309-4. 3rd . Cham . 6.8 Resistive Drift Waves. 933392530.