A folded waveguide coupler for plasma heating in the ion cyclotron range of frequencies

A new type of waveguide coupler for plasma heating experiments in the ion cyclotron range of frequencies (ICRF) is introduced. The coupler consists of a series of interleaved metallic vanes within a rectangular enclosure analogous to a very wide simple rectangular waveguide that has been ''folded'' several times. At the mouth of the coupler a plate is attached which contains coupling apertures in each ''fold'' or every other ''fold'' depending upon the application. This plate serves primarily as a wave field polarizer that converts coupler fields to the polarization of the fast magnetosonic wave within a plasma. Theoretical estimates indicate that the folded waveguide coupler is capable of high-efficiency multimegawatt operation into a plasma