Resonances and anti-resonances of a plasma column in a helicon plasma source☆

Abstract We consider excitation of a plasma cavity in a range of parameters typical for helicon sources. The resonance and anti-resonance properties are shown to be intrinsic for a plasma column in this case, as well as for any bounded plasma system. If a column is well separated from a conductive wall, even small collisions result in the destruction of both resonances and helicon anti-resonances. The anti-resonance states with quenched Trivelpiece-Gould waves turn out to be stable against collisions and ensure enhanced rf power release in the bulk plasma.