Non-Axisymmetric Alfvén Wave Excited by a Helical Coupler in an Inhomogeneous Plasma

Autor: Amagishi, Yoshimitsu, Inutake, Masaaki, Akitsu, Tetsuya, Tsushima, Akira
Zdroj: Japanese Journal of Applied Physics; November 1981, Vol. 20 Issue: 11 p2171-2171, 1p
Abstrakt: Non-axisymmetric Alfvén waves are excited with a helical coupler in a finite beta and a cylindrical inhomogeneous plasma surrounded by a conducting wall. The helical coupler, which consists of two symmetrical helical windings, exhibits a strong propagation directionality; slow waves of the m=-1 mode and fast waves of the m=+1 mode can be launched simultaneously from the coupler, but propagate in opposite directions along the static magnetic field. Dispersion relations including the attenuation length for both modes are compared with a magnetohydrodynamic theory given by Woods on the assumption of appropriate boundary conditions. As a nonlinear phenomenon, subharmonic slow Alfvén waves of the m=-1 mode have been observed when the pump frequency is close to or above the ion cyclotron frequency.
Databáze: Supplemental Index