Excitation of ion Bernstein and ion cyclotron waves by a gyrating ion beam in a plasma column

Gyrating ion beams, produced by quick ionization of neutral beams, employed for plasma heating, are susceptible to ion Bernstein and ion cyclotron instabilities. The Bernstein wave, having large parallel phase velocity, is excited via cyclotron interaction whereas the ion cyclotron wave with lower parallel phase velocity could be driven by Cerenkov interaction as well. The maximally growing modes have transverse wave number of the order of inverse ion Larmor radius. The nonlocal effects cause reduction in the growth rate.