Propagation and damping of the fast Alfven wave in the Texas Tech Tokamak

Date

1983-08

Journal Title

Journal ISSN

Volume Title

Publisher

Texas Tech University

Abstract

Propagation and damping of the fast Alfven wave has been investigated for a deuterium-hydrogen plasma in a small research Tokamak. Magnetic probes served as the principle diagnostic in studying the waves* dispersion characteristics, the eigenmode Q's and the radial profiles of the electrical field polarization. Results indicate that a simple cylindrical model is sufficient for predicting the waves* dispersion properties, Q measurements supply strong evidence that the fast wave damping is dependent on resonance layers in the plasma. The dependence of Q on percentage hydrogen in the predominantly deuterium plasma suggests that mode conversion of the fast wave to the ion Bernstein wave at the ion-ion hybrid resonance layer may be occurring. The measured field patterns differed substantially from theoretical expectations and no localized resonance layer effect was detected in the polarization profiles. However, a more quiescent plasma and better spatial resolution of the probe measurements may help in resolving some mode conversion effects.

Description

Keywords

Plasma heating, Tokamaks, Plasma waves, Damping (Mechanics)

Citation