''Ballistic Damping'': A Proposed Method of Stabilizing Resonant Ion Cyclotron Modes

摘要

The essence of the idea is as follows: One or more beams of energetic ions (or neutral atoms that will become ionized) are injected, parallel to the field lines, at radii where the instability electric field has maximum amplitude (say roughly halfway between the axis and the outer radius of the plasma). While in transit through the plasma these ions acquire transverse energy by resonant acceleration, thereby extracting energy from the wave. This imparted energy is then carried out of the confined plasma by the beam particles as they exit through the far mirror. In this way the ballistic damping process introduces a damping mechanism that can be used to inhibit the growth of unstable waves and/or to damp them out before they reach unacceptably high amplitude. It is also shown that the beam power required is substantially lower than the plasma powers involved, scaling in a favorable way with increase in the size of the mirror cell. (ERA citation 04:002006)