ICRF antennas optimized for operation with a high-Z metallic wall in ASDEX Upgrade

High-Z materials are considered the best candidates for plasma facing components (PFCs) in future fusion devices, while ion cyclotron range of frequencies (ICRF) heating is a method of choice because of its flexibility, cost effectiveness, and plug-to-power efficiency. But high-Z materials and ICRF have been a difficult combination. ASDEX Upgrade (AUG) is pioneering the use of a tungsten (W) wall and in the next years it will prove (or disprove) the appropriateness of this combination for the future. aper describes the optimization procedure for and the main features of a new proposed ICRF antenna for AUG specifically designed to improve the compatibility of ICRF with a high-Z metallic wall. The optimization criteria for a new design are based on a reduction of the parasitic parallel electric field responsible of the impurity production. The evolutionary design of the 2-strap antenna is compared with a redesigned 4-strap antenna embedded in the wall. er, options and constraints on how to integrate a wider antenna in the present configuration of ASDEX Upgrade and its integration on the stabilizing wall are discussed.