Possibility of excitation of azimuthal surface waves in a magnetized plasma by annular ion beams

Excitation of the azimuthal surface eigenmodes with the extraordinary polarization for the ion plasma component is shown to be possible in cylindrical waveguides with metal walls, filled partially by a cold magnetoactive neon plasma. The interaction of the oscillations with the flows of alpha particles rotating around the plasma column in a narrow layer that separates the plasma from the waveguide walls is studied. If the external magnetic field is strong enough, the resonance interaction of the beam with the waves can be realized for three minimum values of the azimuthal mode number when the wave frequency normalized by neon ion cyclotron frequency is close to the factor of five $(m_{\mathrm{Ne}}/m_{\mathrm{He}}\approx 5)$.