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

摘要

A theory is developed irom which it follows that energetic-ion-dnven 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 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 instabilities results in a 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 the effects of Alfvenic activity on the plasma temperature were observed, are considered.