ECCD Studies for a Volumetric Neutron Source (VNS)

We explore the theoretical capabilities of Electron Cyclotron Current Drive (ECCD) in a volumetric neutron source (VNS), a high-neutron-fluence tokamak for component testing and qualification that is being considered in the frame of the EUROfusion Consortium. Two selected applications are addressed, namely bulk current drive in the plasma centre and stabilization of Neoclassical Tearing Modes (NTMs). It is shown that a current drive efficiency above 50 kA/MW can be reached, close to typical values reported for DEMO central ECCD. Suppression of NTMs should require less than 10 MW, but this power might become marginal in case of significant beam broadening caused by density fluctuations. The optimum launcher parameters for the envisaged applications will be further iterated to find the sweet spot between physics and engineering constraints.