Electron Cyclotron Heating and Current Drive studies for the SMART Tokamak

This study presents an initial scoping of Electron Cyclotron Heating and Current Drive (EC H&CD) for the SMall Aspect Ratio Tokamak (SMART), operated by the University of Seville's Plasma Science and Fusion Technology (PSFT) Laboratory. We investigate two planned operational phases with distinct magnetic field strengths: 0.4 T and 1 T. Using the TRAVIS ray tracing code, we rapidly scanned key SMART plasma scenarios. For the 0.4 T scenario, we performed a scan of poloidal and toroidal launching angles from three locations: mid-plane, off-mid-plane, and top-launcher, assuming extraordinary (X-mode) polarization. We observed that absorption occurs at the second harmonic, with the highest power absorption achieved by launching the EC beam from the top of the tokamak. Additionally, we conducted a numerical analysis of the fundamental X-mode EC H&CD start-up regime for the 1.0 T plasma scenario. This analysis, performed with two different wave frequencies (28 and 35 GHz), demonstrates very high current drive efficiency in the linear regime. A series of GENRAY-CQL3D simulations were also performed to investigate the impact of the non-linear effects on the current drive efficiency.