Transport processes of a non-neutral plasma coupled to an external rotating wave

Abstract

Experimental investigations are carried out on radial transport phenomena of a pure electron plasma under the application of an external rotating wave that belongs to Trivelpiece-Gould (T-G) modes. Substantial radial compression of the density distribution is achieved by application of a properly controlled rotating electric field to one side of the plasma. Analyses of the observed plasma wave indicate that the efficient increase of the on-axis density entails the substantial damping of the T-G wave propagating in the plasma. The radial particle flux observed during the density compression is consistent with that of the theoretical model based on the drift-kinetic Vlasov equation [Y. Kiwamoto et al., Phys. Plasmas 12, 094501 (2005)]. This result implies that the radial compression of the plasma density distribution consists of the transverse E×B drift of particles subject to resonant wave-particle interaction in the axial dynamics.