Shear Alfvén waves with transverse scales of electron skin-depth size are launched with a dual-disk antenna in the Large Plasma Device at UCLA. The waves are studied in the kinetic and inertial regimes. The kinetic shear Alfvén wave is observed for the first time and exhibits predicted radial structure. The perpendicular propagation of the wave is also studied for the first time, and it is found to be backward in the inertial regime, as expected. The wave currents are calculated from magnetic field measurements and are found to flow in toroidal vortices.

• Received 14 July 1998

DOI:https://doi.org/10.1103/PhysRevLett.82.2673