Effects of the energetic-ion-driven instabilities on plasma heating, transport, and rotation in toroidal systems

A theory is developed from which it follows that energetic-ion-driven instabilities can, first, channel the energy of the energetic ions outside the region where these ions are located and, second, considerably affect the electron heat flux across the magnetic field. A new mechanism of the frequency chirping is revealed. Namely, it is shown that instabilities caused by the energetic ions can influence the plasma rotation, in which case the development of the instabilities results in variation of the Doppler shift in time. It is concluded that a key factor responsible for the mentioned phenomena is the local imbalance of the wave emission by energetic ions and the wave absorption by electrons along the radius. On the basis of the developed theory, experiments on the stellarator Wendelstein 7-AS and the spherical torus NSTX, where effects of Alfvénic activity on the plasma temperature were observed, are considered. Effects of energetic-ion-driven instabilities 2