SUPERTHERMAL ION-CYCLOTRON HARMONIC EMISSION FROM FUSION AND SPACE PLASMAS - A SINGLE PHYSICAL-MECHANISM

A common mechanism for the observed excitation of waves at sequential multiple ion cyclotron harmonics in the JET tokamak and in various spa ce plasmas is proposed. It is suggested that, in each case, waves on t he fast Alfven-ion Bernstein branch are excited by the magnetoacoustic cyclotron instability, which is driven by an energetic ion distributi on with a local maximum at upsilon(perpendicular to) not equal 0, wher e upsilon(perpendicular to) is the velocity component perpendicular to the magnetic field.