
%0 Journal Article
%A Borg, GG 
%T Guided Propagation of the Alfv&#233;n Wave in a Tokamak
%J Australian Journal of Physics
%D 1996/10/01
%V 49
%N 5
%P 953-966
%K 
%R https://doi.org/10.1071/PH960953
%U https://www.publish.csiro.au/paper/PH960953 
%X Experimental observations are presented of the magnetically guided Alfv&#233;n wave excited directly by a small dipole loop antenna located in the scrape-off layer of a tokamak plasma. This wave is excited most efficiently by antenna current elements aligned along the magnetic field and measurements indicate that, at all frequencies below the ion cyclotron frequency, the wave propagates for several transits around the machine with a high degree of localization about magnetic field lines intersecting the antenna. Along the field, the wave has both a slowly varying amplitude and phase with predominantly radial electric and azimuthal magnetic field components. These experiments demonstrate that the Alfv&#233;n wave can propagate as a magnetically guided TEM mode in plasmas which are highly inhomogeneous. We also present a simplified mathematical description of the wave. 
