Progress in the pre-conceptual design of the auxiliary heating and current drive system for the Tokamak Energy Fusion Pilot Plant

Auxiliary heating and current drive is a crucial aspect of reactor-relevant tokamaks. Tokamak Energy is currently in the design phase of their Fusion Pilot Plant (FPP). Initial investigations for the flat-top phase of plasma scenarios rely exclusively on electron cyclotron (EC) waves as auxiliary heating and current drive source. This work focuses on parametric optimisation of the flat-top EC current drive scheme via ray-tracing simulations for three plasma scenarios, each having different magnetic field and aspect ratio. The purpose of the study is to maximise the normalised current drive efficiency ζ ECCD. It is shown that EC waves in the O mode polarisation are capable of efficiently driving plasma current throughout the plasma volume, supporting the notion that EC waves can be the single auxiliary power source for flat-top operations.