ICRF EDGE INTERACTION GUIDELINES FOR ICRF ANTENNA DESIGN AND INITIAL ICRF/EDGE INTERACTION EXPERIMENTS ON THE TORE SUPRA TOKAMAK/

Understanding ion cyclotron range of frequency (ICRF) antenna interact ion with the edge/scrape-off-layer (SOL) plasma is crucial to building antennas that can survive long-pulse or Steady-state high-power opera tion in plasmas. The global effects of ICRF/edge interactions are disc ussed. The present knowledge of ICRF-induced sheath interactions with the edge and SOL plasmas in magnetic fusion experiments is quantitativ ely reviewed and added to. The design principles and equations governi ng plasma heat loading and the sputtering of Faraday shields and the b umper limiters of ICRF antennas for long-pulse and steady-state device s are presented. Electrostatic sheaths on Faraday shields and bumper l imiters are discussed, and an analytic estimate of the induced direct- current (de) plasma potential at the lateral protection (bumper limite rs) of ICRF antennas is given. This is a new result. This estimated de voltage is used to give the total power flow to the lateral protectio n, and an expression for the power flux is given-also with new results . Equations to use in estimating impurity production (sputtering) and principles for minimizing im purity production are reviewed. Similar e quations and estimates for electromotive radio-frequency sheaths are g iven, and new scaling laws for the de voltage and power flow to the IC RF antenna lateral protection due to electromotive sheaths are propose d, The initial results from the ICRF/edge interaction experiments on T ore Supra are presented and discussed in light of the theoretical and heuristic results given.