Excitation of Bernstein mode in an inhomogeneous collisionless plasma

The cyclotron harmonic waves propagating at right angles to the static magnetic lines of forces, are excited in an inhomogeneous plasma. The measured dispersion relations are in good agreement with a collisionless theory, not only qualitatively but also quantitatively. It is made clear that the excited waves propagate within the core of the plasma bounded by the upper hybrid (ω P 2 ( r )>ω 2 -ω c 2 ), and these waves are propagating rather than standing.