PRODUCTION OF SUPERTHERMAL ELECTRONS AND ION-CYCLOTRON WAVES IN A REVERSED-FIELD-PINCH PLASMA

Production of superthermal electrons through kinetic interactions with electromagnetic fluctuations is studied to account for observations o f fast electrons and ion cyclotron waves in reversed field pinch plasm as. Low-frequency Alfvenic (torsional) modes can interact with electro ns through the Landau resonance when the wavelength perpendicular to t he magnetic field is as small as the ion gyroradius. Such kinetic Alfv en waves induce simultaneous diffusion (double diffusion) in the coord inate and velocity spaces, and produce a field aligned superthermal el ectron beam in the edge region. Microinstabilities are driven by the e lectron-beam and ion cyclotron waves are excited. Through these preces ses the fluctuation energy in the low-frequency regime may be transpor ted to the ion cyclotron frequency regime.