On kinetic electrostatic plasma waves carrying orbital angular momentum

Abstract

A kinetic description of electron plasma waves carrying orbital angular momentum is revisited by introducing a variable transformation, which confirms a more natural representation of wave propagation in electron-ion plasma extendable to an electron-positron plasma. Specifically, the twisted Landau resonance condition is expressed in a consistent way, which expands the resonance region, and hence modifies the usual assumption of decomposition of the susceptibility in axial and poloidal components involving two separate poles. The present formulation is recommended by numerical analysis and comparison with typical results and illustrations.