Dispersion of dipolar electromagnetic waves in a radially inhomogeneous axially magnetized plasma column

The wavelengths and attenuation coefficients of dipolar left and right-hand circularly polarized waves in a radially inhomogeneous axially magnetized plasma column are computed by means of step approximation of the radial plasma density profile. A comparison with theoretical results assuming radial plasma homogeneity shows that the radial plasma inhomogeneity is significant for wave propagation. In particular it facilitates the occurrence of backward waves and increases by up to one order of magnitude the wave attenuation coefficient compared with a homogeneous plasma column having the same average plasma density.