Mikrowellenabsorption in der Nähe der 2. Harmonischen der Elektronenzyklotronfrequenz

In plasmas produced by microwave power the electron density displays a dependence on the magnetic field strength obviously asymmetric with respect to the harmonics of the electron cyclotron frequency. In regions of the magnetic field strength just above the harmonics there are extremely high values of electron density, the density values dropping sharply off towards the other wing of the harmonics. Absorption experiments near the second harmonic at low microwave power — the plasma being produced by different means — reveal a resonant absorption structure in the magnetic field region above the harmonic. This can be attributed to excitation of geometrical eigenmodes of electrostatic. waves propagating perpendicular to the magnetic field (Bernstein waves).