A study of compressional Alfvén waves in a toroidal plasma

Abstract
A pair of loop antenna in a toroidal plasma device is found to excite compressional Alfvén waves in the frequency range of a few times the ion‐cyclotron frequency. Two‐dimensional profiles of the wave field and phase are obtained in a poloidal cross section as well as one‐dimensional radial profiles. The main wave excited is found to have the fundamental poloidal mode number. However the contribution from higher poloidal modes increases at higher wave frequencies and plasma densities. Comparison with theoretical wave profiles shows deviation from a simple cylindrical plasma model.