Design and optimization of a curved three-strap antenna for DTT ICRH system

The Divertor Tokamak Test facility (DTT) aims at demonstrating possible solutions to the power exhaust issue to pave the path to DEMO. Here we present the numerical design and optimization of a three-strap Ion Cyclotron Resonance Heating (ICRH) antenna suitable to deliver Ion Cyclotron Radio Frequency (RF) Power on DTT plasmas. The launcher operates in the frequency range 60 – 90 MHz and here has been studied and optimized by using the commercial RF simulation software CST Studio Suite. The plasma is considered as an equivalent, high permittivity, lossy dielectric. Considering the mechanical and operational severe constraints of DTT, we firstly designed an antenna flat model with the objectives to optimize the structure for coupling a power 1.5 MW to the dielectric load with a progressive phase shift of 180◦ between toroidally adjacent straps. The second part of the work regarded the design and optimization of a parametric curved antenna model in CST, which employs poloidal and toroidal curvatures suitable to better couple RF to DTT plasmas. The antenna curved model has been re-optimized in terms of coupled power and electric field values to match DTT requirements.