Effects of finite drift orbit width and RF-induced spatial transport on plasmas heated by ICRH

The finite drift orbit width, orbit topology and RF-induced transport of resonant ions play an important role in many high power ICRH scenarios in hot plasmas. Wave-particle interactions with waves propagating in the co-current direction produce an inward drift of trapped orbits ultimately detrapping them into passing orbits when the turning points meet. The drift of ions across magnetic flux surfaces gives rise to a torque on the background plasma. Due to the finite orbit width and the finite Doppler shift of the cyclotron resonance, the drifts and hence the torques do not cancel even for toroidally symmetric wave spectra. An inward drift appears near the center and an outward further out giving rise to a differential acceleration of the plasma.