A novel instability concept, namely, a two-streaming process in gyrospace, is investigated. This leads to a two-energy-stream cyclotron instability even without beams in real space, where fast ions drive electrostatic ion Bernstein waves unstable. The instability comes from the coupling of the fast and slow ion Bernstein branches due to a weak relativistic effect. When an unstable condition is satisfied, the growth rate of the cubic instability is proportional to (nf/ns) 1 3(γf-1) 1 3 while the efficiency ∝ (nf/ns) 1 3(γf-1) -2 3. A quadratic instability dominates high harmonics at the lower-hybrid frequency regime and its growth rate has no γf-1 dependence. The mechanism may play an important role in the interaction and dynamics of fast ions in magnetized plasmas.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)