2-DIMENSIONAL REFLECTION OF MAGNETOSONIC RADIATION BY GYROBALLISTIC WAVES - AN ANALYTIC THEORY

For the first time, the three-step process (conversion-propagation-con version) underlying gyroresonant reflection is analytically developed for two-dimensional geometry. Phase-space methods are used for the con version of an incident magnetosonic wave field to a continuum of gyrob allistic waves, for their propagation along guiding-center orbits in t he poloidal plane of a tokamak, and for their conversion to the two-di mensional magnetosonic reflection field. The wave fronts and amplitude of that field are obtained explicitly.