Wave spectrum of a conducting cylinder in an isotropic plasma

The boundary value problem of the propagation of an electromagnetic field along a cylindrical conductor in an isotropic plasma medium has been solved by the impedance method. The boundedness of the wave spectrum of such a guiding structure has been shown. The spectrum includes fast intrinsic wave $E_{01}$ and extrinsic hybrid waves $HE_{nm}$ and $EH_{nm}$, both fast and slow ones, their countable set being determined by the azimuthal index.