Fine structure of density ducts formed by active radiofrequency action on laboratory and space plasmas

The results of active ionospheric and model laboratory experiments on the generation of artificial irregularities of a magnetized plasma (density ducts), which can be used as waveguide channels for low-frequency waves, have been reported. It has been found that ducts formed at the localized high-frequency heating of the plasma have a fine structure under certain conditions: they include irregularities of the plasma density, which significantly affect the propagation of low-frequency waves, ensuring the deep amplitude modulation of low-frequency radiation and changing its spatial structure. A mechanism of the formation of such irregularities has been proposed.