There is considerable interest in the use of energetic ion beams to heat magnetically confined plasmas to ignition temperature. An uncertainty in this heating technique is the possible role of instabilities driven by the fast ion beams. For this reason, we have investigated homogeneous plasma modes, including the cross field ion-ion wave and the beam ion-acoustic wave, as well as the ordinary electromagnetic mode, which taps the free energy associated with the beam anisotropy. The growth rates of these modes are calculated and the stability thresholds are compared to parameters for both present injection experiments and the proposed TFTR device.
Role of Plasma Elongation on Turbulent Transport in Magnetically Confined Plasmas
