ICRF heating scenarios for the IGNITOR machine

A large frequency range ICRF antenna (70<f<140 MHz) is proposed for the IGNITOR machine, in order to allow either hydrogen or helium-3 minority heating for all the planned operating scenarios. Results from a feasibility study for such a heating system are presented. The power absorbed by the different plasma species as a function of plasma parameters for different heating scenarios was calculated using both 1-dimensional and 2-dimensional kinetic wave codes. Different alternatives are proposed in order to improve heating performances while accounting for the effects of collisional redistribution of the absorbed power. Wave absorption is predicted to be very strong for a number of different RF scenarios. Single pass absorption by alpha particles, as given by a 1-dimensional integral kinetic wave code, is also discussed. (orig.)