Radio-frequency (rf) forces and wave helicity transport

A kinetic theory is developed which unifies the concept of radio‐frequency (rf) current drive and wave helicity injection. It is shown that wave helicity injection and transport can be incorporated into the more general concept of rf forces. Moreover, the part related to wave helicity has the same form as a mean field dynamo. Present result suggests that the evaluation of rf current drive by conventional methods may leave out some important effects. The theory may also simplify the study of rf influence on transport and stability.